* s   '% 
 
A
   SYSTEM OF ANATOMY

                FOR THE USE OF


         STUDENTS  OF MEDICINE




         BY CASPAR WISTAR, M. D.
LATE PROFESSOR OF ANATOMY IN THE UNIVERSITY OF PENNSYLVANIA.
    FOURTH EDITION.

WITH NOTES AND ADDITIONS.
   BY WILLIAM EDMONDS HORNER,  vf. D.

ADJUNCT PROFESSOE OF ANATOMY IN THE TTNIVERSITY OF PENNSYLVA-
   NIA, MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, &t
IS TWO VOLUMES—VOL. II.
        'PHILADELPHIA:
CAREY, LEAV& CAREY—CHESNUT STREET.

               1«27 
                        '.wens


                             IS2.1






    EASTERN DISTRICT OF PENNSYLVANIA, TO WIT:

               BE IT REMEMBERED, that on  the twentieth day
             of August in the forty-ninth year of the Independence of
             the United States of America, A. D. 1825, H. C. Carey
             & I. Lea, of the said district, have deposited in this office
             the title of a  book, the right whereof they claim as Pro-
             prietors, in the words following, to wit:

  " A  System of  Aanatomy for  the use of Students of Medicine.  By
    " Caspar Wistar, M- D. Late Professor of Anatomy in the Universi-
    ty of Pennsylvania.  Third edition*  With notes and additions.  By
    " William Edmonds Homer, M. D. Adjunct Professor of Anatomy
    " in the University of Pennsylvania, and member of the American
    " Philosophical Society, &c.  In two volumes, Volume II."

  In conformity to the act of the  Congress of the United States,  entitled,
" An Act  for the Encouragement of Learning, by securing the copies of
Maps,  Charts, and Books, to the authors and proprietors of such copies,
during the times therein mentioned." And also  to the act, entitled, " An
Act supplementary to an Act, entitled " An  Act  for the Encouragement
of Learning, by securing the  copies of  Maps, Charts, and Books, to the
authors and proprietors of such copies during the times therein mentioned,"
and extending the benefits thereof to the arts of designing, engraving, and
etching historical and other prints."
                                           D. CALDWELL,
                     Clerk of the Eastern District of Pennsylvania.
 
CONTENTS  OF  TOL.  II.
                  PART VI.
   OF THE NOSE—THE MOUTH—AND THE THROAT.
                 CHAPTER I.
                  Of the Nose.
                  SECTION I.
Of the External Nose......        2
                 SECTION II.
Of the Cavities of the Nose   -----     4
                 CHAPTER II.
        Of the Mouth and- the Salivary Glands.
Of the Mouth      -    -   -    -■   -    -    -    14
Of the Salivary Glands  -   -    -   - *   -    -    25
                 CHAPTER III.
                 Of the Throat.
                  SECTION I.
Of the Isthmus of the Fauces     -   -   ■ -    -    29
                 SECTION II.
Of the Larynx.......31
Of the Thyroid Gland......37
                 SECTION III.
Of the Pharynx.......37 
IV
noxixx'i's.
                   PART  VII.
                 OF THE THORAX.
                   CHAPTER I.
         Of the General Cavity of the Thorax.
                    SECTION I.
Of the Form of the Cavity of the Thorax     -    -    44
                    SECTION II.
Of the Arrangement of the Pleurae                   45
Preparation of the Thorax.....47
                   CHAPTER II.
  Of the Heart and the Pericardium, and the Great Vessels
                connected with the Heart.
                    SECTION I.
Of the Pericardium......49
                    SECTION II.
Of the Heart      -   -    -     -"   -    -    -    50
                   SECTION III.
Of the Aorta, the Pulmonary Artery and Veins,  and the
   Venae Cavae at their commencement                 59
                   CHAPTER III.
               Of the Trachea and Lungs.
                    SECTION L
 Of the Trachea.......62
 The Black Glands on the Bronchiae                   64
                    SECTION II.
 Of the  Lungs.....--65
 Thorax of the Foetus    ------    69
 Physiological observations, &c.     -     -    -     -    71 
                     CONTESTS,                     V

                   PART  VIII.

                 OF THE ABDOMEN.

                   CHAPTER I.

A general view of the  Abdomen and Pelvis, and their Con-
        tents ; ivith an Account of the Peritoneum.

                    SECTION I.
Construction of the Abdomen.....82
Contents of the Abdomen.....85

                   SECTION II.
Of the Peritoneum -------    90

                   CHAPTER II.

    Of the Oesophagus, the Stomach, and the Intestines.

                    SECTION I.
Of the Oesophagus -    ,    -    -    -         -    94

                   SECTION II.
Of the Stomach.......96
Of the Gastric Liquor......101

                   SECTION III.
Of the Intestines.......104
Division of  the Intestines.....109
The Small Intestines    r- .   t    -    -    -       110
The Duodenum    -......Ill
Jejunum and Ileon -    -    -    -    -    -    -113
The Mesentery.......115
Of the Great intestines......117
The Caecum and Colon  -    -    -    -    -    -118
The Rectum  --------   122
The Omentum     -    -    -    .    .    _    -125

                   CHAPTER III.

        Of the Liver, the Pancreas, and the Spleen.

                    SECTION I.
Of the Liver  ---.;«_-   128 
VI
CONTIiJCTi. ■
                   SECTION II.
Of the Pancreas         -    -    -    -   -    -    141

                   SECTION III.
Of the Spleen     -------    145

                  CHAPTER IV.
    Of the Urinary Organs, and the Glandules Senates.
                   SECTION I.
Of the Glandulae Renales.....154
                   SECTION II.
Of the Kidneys and Ureters  -    -    -   -    -    155
                   SECTION III.
Of the Urinary Bladder......162

                   CHAPTER V.
          Of the Male  Organs of Generation.
                   SECTION I.
Of the Testicles and their Appendages   -   -    -171
                   SECTION II.
Of the Vesieulae Seminales and the Prostate Gland  -    181

                   SECTION III.
Of the Penis........184

                  CHAPTER VI.
         Of the Female Organs of Generation.
                   SECTION I.
Of the External Parts of  Generation    -            2O0

                   SECTION II.
Of the Vagina     -     - '  -    -    -   -    -    203
                   SECTION III.
Of the Uterus, the Ovaries, and their Appendages  -    205

                   SECTION IV.
Of the Bladder and Urethra  -                     213 
                     CONTENTS.                    VU

                    PART IX.

               OF THE BLOOD VESSELS'.

                    CHAPTER I.

Of the General Structure and arrangement ofthe Blood Vessels,

                    SECTION I.         "i '
Of the Arteries     -    -    -  ■  -    -   -    -   226

                    SECTION II.
Of the Veins........233

                   CHAPTER II.

  A Particular Account of the Distri&Uion of the Arteries.

                    SECTION I.
Of the Aorta, or the Great Trunk of the Arterial System  236

                   SECTION  II.
Of the Branches which go off from the Arcli of the Aorta  238

                   SECTION  III.
Of the Branches which go off between the Arch and the
  Great Bifurcation of the Aorta   -                 272

                   SECTION  IV.
Of the Arteries which originate at  and below the Great
  Bifurcation of the Aorta.....283

                  CHAPTER  III.

      Of the particular Distribution of the Veins.

                    SECTION T.
Of the Superior, or Descending  Vena Cava, and  the
  Veins which communicate with it      -            ^.jo

                   SEQTION  II.
Of the Inferior Vena  Cava, and the  veins connected
  \\i+h it      -    -    .         -     •   *     _   309 
 Vlll                  CONTENTS.

                     PART X.

                   OF THE NERVES.

 Nerves of the Brain    »  .  -
 Of the Cervical Nerves  -
 Nerves of the Diaphragm
 Brachial Plexus    -   -    -   -
 Nerves of the Arm -
 The Dorsal Nerve3 -   -    -   -
 Of the Lumbar Nerves  -
 The Sacral Nerves -   -    -   -
 Sciatic Plexus      -
 Great Sciatic Nerve     -
 Great Sympathetic Nerve
 Nerves of the Heart    -
 Nerves of the Abdominal Viscera  -


                    PART XI.

             OF THE ABSORBENT VESSELS.

                   CHAPTER I.

 Of the Absorbents of the Lower Extremities—the Abdomen
                   and the Thorax.

                   SECTION I.
The Absorbents of the Lower Extremities    -    -   376

                   SECTION II.
The Absorbents of the Abdomen and Thorax -    -   381

                   CHAPTER II.

 Of the Absorbents of the Head and Nech, of the Upper Ex-
  tremities, and the Upper Part  of the  Trunk of the Body.

                   SECTION I.
Of the Absorbents of the Head and Neck     -    -   391

                   SECTION II.
Of the Absorbents of the Arm, and Upper Part of the
  Trunk.......„   393
-   328
-   343
-   346
-   347
-   348
-   352
-   353
-   356
-   357
-   358
-   361
-   363
-   368 
SYSTEM OF ANATOMY.
PART VI.
OF THE NOSE: THE MOUTH : AND THE THROAT.
                 CHAPTER I.


                  OF THE NOSE.

  The prominent part of the face,  to which the
Word  nose  is  exclusively  applied in  ordinary  lan-
guage, is the anterior covering of two cavities which
contain the organ of  smelling.
  These  cavities are formed principally by the upper
maxillary and palate bones; and, therefore, to acquire
a complete idea of them, it is necessary to study these
bones, as well as the  os ethmoides,  the  vomer, and
the ossa spongiosa inferiora, which are likewise con-
cerned in their formation.
  In  addition  to the description  of these  bones, ifl
the account of the bones of the head, it will  be use-
ful to study the description of the cavities of tte nose
which follows it.  See vol. I. page 64.
  After thus acquiring a knowledge of the bony struc-
ture,  the student will be prepared for a description
of the softer parts.
  V«»L, II.             1 
The External Nose.
                    SECTION i.

              Of the External Nose.

  The superior part of the nose is formed by the
ossa nasi, and the nasal processes of the upper max-
illary bones, which have been already described; (see
vol. I. pages 42—46,) but the inferior part, which
is composed principally of cartilages, is much more
complex in its structure.
  The orifice, formed by the upper maxillary and
nasal  bones, is divided  by  a  cartilaginous plate,
which is the anterior and inferior part of the sep-
tum,  or partition  between  the two cavities of the
nose.   The anterior edge of this plate  projects be-
yond  the orifice in the  bones, and continues in the
direction of the suture between the ossa nasi.  This
edge forms an angle with the lower edge of the same
cartilage, which continues from it,  in  a  horizontal
direction, until it reaches the lower  part of the ori-
fice of the nose, at the junction of the palatine pro-
cesses of  the upper maxillary bones; where  a  bony
prominence is  formed, to which it is firmly united.
The upper  part of the anterior  edge of this carti-
lage, which is  in contact with the ossa nasi, is flat,
and is continued into two  lateral portions that are
extended from it, one on each side, and form a part
of the nose: these  lateral portions are sometimes spo-
ken of as distinct cartilages: but they are  really con-
tinuations of the middle portion or septum.
  Below the lower edge of  these  lateral portions are
situated the cartilages which form the orifices of the
nose, %r the nostrils.   Of these, there is one of con-
siderable size, and several  small  fragments,  on each
side of the septum.   Each of the larger  cartilages
forms a portion of an oval ring, which is placed ob-
liquely on the side of the septum: «o that the cxtre- 
                   Of the Nose.                 3

 mity of the oval points downward and forward, while
 the  middle part of the oval is directed upwards and
 backwards.  The sides of this cartilage are flat, and
 unequal in breadth.  The narrowest side  is internal,
 and  projects lower down than the cartilaginous sep-
 tum ;  so that it is applied to  its fellow of the other
 nostril.  The external side is broader, and continues
 backward and upward to  a considerable distance.
   The upper and posterior part of this oval ring is
 deficient;  but  the remainder of the nostril consists
 of several  small pieces of cartilage, which are fixed
 in a ligamentous membrane that is connected by each
 of its extremities to the oval cartilage, and thus com-
 pletes the  orifice.
   The anterior parts of the oval cartilages form the
 point of the nose ;  and the ligamentous portions, the
 alae  or lateral parts of the nostrils.
   When the external integuments and muscles are
 removed from the lower portion of the nose, so that
 the internal membrane and these cartilages only re-
 main, the internal membrane will be found attached
 to the  whole bony margin of each orifice, and to each
 side  of the whole anterior edge of the middle carti-
 lage, which projects beyond the bones.  This mem-
 brane is afterwards continued  so  as to line the oval
 cartilages and the  elastic membrane of the ala nasi,
 to the  margin of the orifice of the nostril.
  The internal portions of the oval cartilages being
situated without the  septum, and  applied to each
other,  they form the eternal  edge of the partition
 between the nostrils, or the columna nasi; which  is
very moveable  upon  the  edge of the  middle carti-
lage.
  The orifices of the nostrils, thus constructed, are
 dilated by that portion of the muscle, called Levator
Lubii  Superioris  Mseque Nasi, which  is inserted
into  the aire nasi. 
4          Of the Cavities of the Nose.

  They are drawn down by the depressor labii supe-
rioris alseque nasi. They are pressed against the sep-
tum and the nose by the  muscle called Compressor
Naris9 which  has however an opposite effect when
its upper extremity is drawn upwards by those fibres
of the occipito-frontalis,  which  descend upon  the
nose,  and are in contact with it.
  The end of the nose  is also  occasionally drawn
down, by some muscular fibres which descend from
it, on the septum of the nose, to the orbicularis oris:
they are considered as a portion of this musele by
many anatomists, but were described by Albinus as
a separate muscle, and called Nasalis Labii Supe-
rio?*is.
  When inspiration takes place with great force, the
alse nasi would be pressed against the septum if they
were not drawn out and dilated by some of the mus-i
cles above  mentioned.

                    SECTION II.

           Of the  Cavities of the Nose.

   To the description of the osseous parts of the nasal
cavities in  vol. I. page 64, it ought now to be added
that the vacuity in the anterior part of the osseous
septum is filled up by  a cartilaginous plate, connect-
ed with the nasal lamella of the ethmoid bone above,
and  with  the  vomer  below.   This  plate sends off
those lateral portions  already described, which  form
the  cartilaginous part  of  the bridge of the nose.
   It should also be observed that at  the back parts
 of these cavities are two orifices called the Posterior
 Nares, which are formed by the palate bones, the
 vomer,  and  the  body of the sphenoidal  bone, and
 are somewhat oval.
   The nasal cavities,  thus constructed, are lined by
 a peculiar membrane, which is called pituitary from, 
Schneiderian Membrane.           5
its secretion of mucus, or Schneiderian after an ana-
tomist who described it with accuracy.*
  This  membrane  is very  thick  and  strong,  and
abounds with so  many blood vessels, that in the liv-
ing subject it is of a red colour.  It adheres to the
bones and septum of the nose  like the periosteum,
but separates from them more  easily.   The  surface
which adheres to the  bones lias some resemblance to
periosteum ;  while  the  other surface is soft, spongy,
and rather villous.  Bichat seems to have considered
this membrane as formed of two lamina, viz.  perios-
teum, and the  proper mucous membrane ;  but he
adds, that it is almost impossible to separate them.
  It has been supposed that many distinct glandular
bodies were to be seen in  the structure  of this mem-
brane by examining the surface next to the bones ;f
but this opinion is adopted by very few of the anato-
mists of the present day.   The texture of the mem-
brane appears to be uniform ;  and on its surface are
a great  number of follicles of various sizes,  from
which flows the mucous of the nose.
  These follicles appear like pits,  made by pushing
a pin obliquely into a surface which retains the form
of the impression.  They can be seen very distinctly
with a common magnifying glass when the membrane
is immersed in water, both on the septum and on the
opposite surface. They are scattered over the mem-
brane without order or regularity, except that  in  a
few places they occur so as to form lines of various
lengths, from half an inch to an  inch.   The largest
of them are in the  lower parts of the cavities.
   It may be presumed that the secretion of mucous is
effected hereby vessels which are mere  continuations
of arteries spread  upon a  surface analogous to the

  * Conrad Schneider, a German professor, in  a large work, " De Ca-
tarrhis," imMished about 1(560.
  * St- W hi slow, section X. No. 837. 
 6               Olfactory Nerves.

 exhalents,  and  not convoluted  in  circumscribed
 masses, as in the case of ordinary glands.
   The arteries of this  membrane are derived from
 various sources :  the most important of them is the
 nasal branch of the internal maxillary, which passes
 into the  nose through the spheno-palatine foramen,
 and is therefore called  the Spheno-palatine Artery.
 It divides into several twigs, which  are  spent  upon
 the different parts of the surface of the nasal cavities.
 Two of them are generally found on the septum of
 the nose : one, which is small, passes forwards near
 the middle ; the other,  which is much larger, is near
 the lower part of it.
   Two small arteries called the anterior and poste-
 rior ethmoidal, which  are branches of the ophthal-
 mic,  enter  the  nose  by foramina  of the cribriform
 plate of the ethmoidal  bone.  These arteries  pass
 from the orbit to the cavity of the cranium, and then
 through the cribriform  plate  to the nose.  In addi-
 tion to these, there are  some  small arteries derived
 from the infra orbital, the alveolar and the palatine,
 which extend to  the  Schneiderian membrane ; but
 they are not of much importance.
  The veins of the nose correspond with the arteries.
 Those wftich accompany the ethmoidal arteries open
 into the ocular vein of the orbit, which terminates in
 the cavernous sinuses of the head.   The other veins
 ultimately terminate in the external jugulars.
   The nerves of the nose form an important part of
the structure; they are derived from several sources;
but the most important branches are  those of the ol-
factory.
  The olfactory nerves  form oblong bulbs, which lie
on each side of the crista galli, on the depressed por-
 tions of the  cribriform  plate  of the  ethmoid bone,
 within the dura mater.  These bulbs are of a soft con-
 sistence, and resemble the cortical part of the brain 
Olfactory Nerves.
7
 mixed with streaks of medullary matter.  They send
 off numerous filaments, which pass through the fora-
 mina of the ethmoid bone, and receive a coat from
 the dura mater as they pass through it
   These filaments are so arranged that they form two
 rows, one running near to the septum,  and the other
 to the surface of the cellular part of the ethmoid bone,
 and the os turbinatum :  and in addition to these are
 some intermediate filaments.
   When the Schneiderian membrane is peeled from
 the bones to which  it is attached, these nervous fila-
 ments are seen  passing from the foramina of the eth-
 moid bone to the attached surfaces : one row passing
 upon that which covered the septum,  and the other
 to that of the opposite side; while the intermediate
 filaments take an anterior direction, but unite to the
 membrane as soon as they come in contact with it.
   All of these can be traced downwards on the afore-
 said surfaces of the  membrane for a considerable dis-
 tance, when they gradually sink into the substance of
 the membrane,  and most probably terminate on the
internal villous surface; but they have not been traced
 to their ultimate termination.   They ramify so that
 the branches form very acute angles with each other.
 On the septum  the different branches are arranged so
as to form brushes, which lie  in  contact with each
other.  On the opposite sides, the different ramifica-
tions unite so as to form a plexus.
   Dr.  Soemmering published  last  year  some very
elegant engravings of the nose, representing one of
his dissections,  which appears  to  have  been uncom-
monly minute and successful.*   These  represent the
ramifications as  becoming more  expanded and deli-
cate in the progress towards their terminations, and
* They are entitled, Icones organorum humanorum olfactus. 
Z Sphenopalatine and other Nerves of the Nose.

as observing a tortuous course, with very short mean-
dering flexures.                        .        ,
  It is to be observed that the ramifications ot  me
olfactory nerve, thus arranged, do not extend to the
bottom of the cavity.  On the external side, they are
not traced lower than the lower edge of the ethmoid,
or of the superior spongy bone :  and on the septum,
they do not extend to the bottom, although they are
lower than  on the opposite side.   On the parts of the
membrane not occupied  by the branches of the olfac-
tory nerves, several other nerves can be traced.  The
nasal twig of the ophthalmic branch of the fifth pair,
after passing  from  the orbit into the  cavity of the
cranium, proceeds to the  nasal cavity on  each side
by a foramen  of the cribriform plate  ; and after send-
ing off some fibrillae, descends upon  the anterior part
of the septum to the point of the nose.   The sphe-
no-palatine nerve, which is derived from the second
branch of the fifth pair, and enters the nose by the
spheno-palatine foramen, is spread  upon  the  lower
part of the septum and  of the opposite side of the
nose also, and transmits  a branch  through a canal in
the foramen incisivum to the mouth.  Several small
branches also pass to the nose from  the  palatine and
other nerves  ; but those already mentioned are the
most important.
  A question has been proposed, whether the olfac-
tory nerve  is exclusively concerned in  the  function
of smelling, or whether  the other nerves above men-
tioned are  also concerned  in it.   It seems probable
that this function is exclusively performed  by the
olfactory nerve, and that  the other nerves  are  like
the ophthalmic branch of  the fifth pair, with respect
to the optic nerve.  In proof  of this,  it  is asserted
that the sense of smelling  has entirely ceased in some
cases, where the sensibility to  mechanical irritation
of every kind has remained unchanged.  If the ol- 
      Extent of the Schneiderian Membrane.     9

factory nerve alone is concerned  in  the  function of
smelling, it follows, that this function must be confin-
ed to the upper parts of the nasal  cavities ; but it
ought to be remembered,  that the structure of the
Schneiderian membrane, in the lower parts of these
cavities, appears exactly like that which is above.
  The surface of the nasal cavities and their septum,
when covered with the Schneiderian membrane, cor-
responds with  the osseous  surface formerly  descri-
bed.  The membrane covers the bones and cartilage
of the septum,  so  as  to make one  uniform regular
surface.  From the upper part of the septum,  it is
continued to the under side of the  cribriform plate
of the ethmoid,  and lines  it; the  filaments of the
olfactory nerve passing through the foramina  of that
bone into the fibrous surface of the  membrane.  It
is continued from the  septum, and from  the  cribri-
form plate,  to the internal  surface of the external
nose, and lines it.   It is also continued backwards to
the anterior surface of the body of the sphenoidal
bone ; and, passing through the foramina or openings
of the sphenoidal cells,  it lines these cavities com-
pletely ; but in these, as well as  the other cavities,
its structure appears somewhat changed; it becomes
thinner  and less vascular.
  At the above mentioned foramina, in some subjects,
it forms a plait or fold,  which diminishes the aper-
ture considerably.
  From the upper surface of the nasal cavities, the
membrane is continued downwards over  the surface
opposite to the  septum.   On the  upper flat surfaces
of the cellular  portions of the ethmoid, it forms  a
smooth uniform surface.   After passing over the first
turbinated bone, or that called after Morgagni,  it is
reflected into the groove, or upper meatus, immedi-
ately within and under it;  the fold formed  by the
membrane, as it is reflected into the meatus, is rather
  Vol.  ti.                2 
    10 Distribution of the Schneiderian Membrane.

    larger than the bone: and the edge of the fold there-
    fore extends lower done than  the  edge of the bone,
    and partly covers the meatus like a flap, consisting
    only of the doubled membrane.  This  fold generally
    continues backwards as far as the spheno-maxillary
    foramen, which it closes; the periosteum, exterior to
    the foramen, passing through  it, and blending itself
    with the  fibrous  surface of the  Schneide an mem-
    brane within.  Here the spheno-palatine nerves and
    arteries join the  membrane.   Below this meatus, it
    extends over the middle, (formerly called  the upper,)
    turbinated bone, and  is reflected  or folded inwards
    on the under side of this bone,  and continued  into
    the middle meatus below it.  In the middle  meatus,
    which is partly covered by the last-mentioned turbir
    nated bone, there are two  foramina: one communi-
    cating with  the maxillary sinus;  and the other with
    the anterior cells of the ethmoid  and  the frontal si-
    nuses.   The aperture into the  maxillary sinuses is
    much less in the recent  head, in which the  Schnei-
    derian membrane lines the  nose, than it is in  the
    bare bones.   A portion of the aperture in the bones
    is closed by the  Schneiderian membrane, which is
    extended  over it:  the remainder of the  aperture is
    unclosed; and through this foramen, the membrane
    is reflected so as to line the whole cavity.   As a por-
    tion of the foramen is covered by the membrane, and
    this portion as well as the  other parts of the cavity
    is lined by the membrane, it  is  obvious  that at  the
    place where the membrane  is  extended over  the
-   foramen in  the bone, it must be doubled ; or, in
    other words, a part of the aperture of  the maxillary
    sinus is closed by a fold of the Schneiderian mem-
    brane.
      This aperture varies in size in different subjects,
    and is often equal in diameter to a common quill.   It
    is situated in the middle of the meatus, and is covered 
Eustachian Tube.
11
by the middle turbinated bone: immediately above it,
is a prominence of the cellular structure of the eth-
moid bone, which has a curved or semicircular figure.
Near this prominence, in the same meatus, a groove
terminates, which leads from the  anterior ethmoid
cells and the frontal sinuses.
  From the middle meatus, the membrane  proceeds
over the inferior turbinated  bone, and is  reflected
round and under it into the lower meatus.  It appears
rather larger than the  bone which  it covers; and
therefore the lower edge of the bone does not extend
so low as the lower edge of the membrane, which of
course is like a fold or plait.   The membrane  then
continues and lines the lower meatus:  here it appears
less full than it is in  the turbinated  bone.   In this
meatus, near to its anterior end, is  the lower orifice
of the lachrymal duct:  this is  simply lined by the
Schneiderian membrane, which is continued into  it,
and forms no plaits or folds that affect the orifice.

         Orifice of the Eustachian Tube.
  Immediately behind each of the nasal cavities, on
the external side, is  the orifice of the Eustachian
Tube.  It has  an oval form, and is large enough to
admit a  very large quill.   Its  position is  oblique;
the upper extremity being anterior to the other parts
of the aperture, and on a line with the middle mea-
tus, while the centre is behind the inferior turbinated
bone.  The lower part of the oval is deficient.  This
tube is formed  posteriorly by a cartilaginous plate.
It is lined by the membrane continued from the nose.

      The cavities of the nose answer a twofold  purpose in
        the animal economy: they art'oid  a surface for the
        expansion of the  olfactory nerves: and a passage
        for the external air to the windpipe, in respiration.
      The function of smelling appears to be dependent, to
        a certain degree, upon respiration.  It has been as- 
12       Observations respecting the Nose.

        serted that unless the air passes in a stream through
        the nose, as in respiration, the perception ot odour
        does not take place; that in persons who breathe
        through wounds and apertures in the windpipe, the
        function of smelling is not performed.  It is rather
        in confirmation of this proposition, that  most per-
        sons, when they wish to have an accurate perception
        of any odour, draw in air rapidly through the nose.
      Although the  ultimate  terminations of the olfactory
        nerves cannot be demonstrated like those of the op-
        tic and auditory nerves, it is probable, from the ap-
        pearance of the fibres, while they are  distinguisha-
        ble, that they are finally arranged with great delica-
        cy.  It is certain that the impressions  from whence
        we derive the perceptions of many odours must be
        very slight; as some odorous bodies will impregnate
        the air of a large chamber for a great length of time,
        without losing any sensible weight.
      With respect to delicacy of structure and sensibility,
        it is probable that the nose holds a middle rank be-
        tween the eye or ear, and the  tongue : and on this
        account the  mucous is necessary as a covering and
        defence of its surface-
      It has been ascertained, by the investigations of  che-
        mists, that this mucous  contains the same ingredi-
         ents as the tears already described, viz. animal mu-
         cous and water; with muriate of soda, and soda un-
         combined; phosphate of lime, and phosphate of soda.
       The animal mucous, which is a most important ingre-
         dient in the composition, resembles the mucilage
         formed by some of the  vegetable gums in several
         particulars; and differs  from them in others.
       The mucous of the nose, if it remain there long after
         it is secreted,  becomes  much  more viscid in  con-
         sistence, and changes from a whitish  colour to one
         which partakes more or less of the yellow.  It is
         probable that an incipient putrefaction may occasion
         these changes in it.
       The use of the frontal, maxillary and  other sinuses,
         communicating with the nose,  has  been  the subject
         of some inquiry.   As there can be no stream of air
         through them, and as the membrane  lining them is
         neither so thick, villous nor flexible as  that lining
         the nose, it may be concluded, a priori, that  they
         are not concerned in the function of smelling.   This 
Use of the Sinuses of the Nose.          13
  opinion is strengthened by the fact, that very young
  children, in whom these sinuses scarcely exist, en-
  joy the sense of smelling  in  perfection.   The fol-
  lowing fact is also in support of it.   The celebrated
  Desault  attended  a patient,  in  whom one  of the
  frontal sinuses was laid open by the destruction  of
  the bone which covered it anteriorly.  This patient
  was able to breathe a  short time through the sinus
  when the mouth and nose were closed :  At the re-
  quest of Desault he breathed in  this manner when
  a cup of some aromatic liquor was  held near the
  opening of the sinus :  and had not the least percep-
  tion of odour.  This  experiment was repeated se-
  veral  times.
Many physiologists believe that these sinuses have an
  effect in modulating the voice. 
CHAPTER II.
                  OF THE MOUTH.

   The general cavity of the  mouth is formed ante-
riorly and laterally by the connexion of the lips and
cheeks to the upper and lower jaws ; so that the teeth
and the  alveoli of both jaws  may be considered as
within the cavity.  Above, it is bounded principally
by the palatine processes of the upper maxillary and
palate bones,  and the soft  palate, which continues
backward from them in the same direction.
   Below, the cavity is completed by several muscles,
which proceed from almost the whole internal circum-
ference of the lower jaw, and, by their connexions
with each other, with the tongue and the os hyoides,
form a floor or bottom to it. The tongue is particular-
ly connected to this  surface, and may be considered
as resting upon and supported by it.
   To acquire an idea of the parietes of this cavity,
after studying the upper and  lower maxillary bones,
the orbicularis oris and the muscles connected with it,
especially the buccinator, ought to be examined ;  and
also the digastricus,  the mylo-hyoideus, genioiiyoi-
deus, and genio-hyoglossus.   By this it will appear
that the lips and cheeks, and  the basis or floor of the
mouth,  are  formed  in a great measure by muscles.
Upon the internal  surface of these  muscles, a por-
tion of cellular and adipose  substance is arranged,
as well as glandular bodies of  different sizes ; and to
these is attached the membrane which lines the in-
side of the  mouth.
   This membrane passes from the skin  of the face
to the lips,  and the inside of the mouth; and, al-
though it is really a  continuation of the skin, there 
Internal Surface of the Mouth.       15
is so great a change of structure, that it ought to be
considered as a different membrane.  At the orifice
of the lips it is extremely thin, and so vascular that
it produces the fine florid colour which appears there
in health.  It is covered by a cuticle, called by some
anatomists,  Epithelium, which  has a  proportionate
degree of delicacy, and can be separated. like the
cuticle in other parts.   When this cuticle is separa-
ted,  the lips and the membrane  of the mouth appear
to be covered with very fine villi, which  are  parti-
cularly apparent in some preparations of the lips af-
ter injection and maceration.*
  Under this membrane are many small glandular
bodies of a roundish form,  called glandulae labiales,
whose excretory ducts  pass through it to the inner
surface of the mouth, for the purpose of lubrifying
it with their secretion, which  is  mingled with  the
saliva.
  The membrane, which lines the inside  of the lips
and cheeks,  is somewhat different from  that  which
forms the surface of the orifice  of the mouth  : it is
not so florid ; the blood vessels  in  its texture  are
larger and not so numerous.  This change, however,
takes place very gradually, in  the progress of the
membrane, from the orifice of the lips to the back
part of the cheeks.  Glandular bodies, like those of
the  lips, are  situated  immediately exterior to  this
membrane of the cheeks, between it and the mus-
cles  : their ducts open on its surface.  These glands
are called Buccales.
  This lining membrane is continued from the inter-
nal surface of the lips and cheeks to the alveolar por-
tions of the  upper and lower jaws, which are  in the
cavity  of the  mouth,   and covers them, adhering
firmly to the periosteum.

  * Ruysch  had a fine preparation of this structure.  See Thesaurus VII
Tab. III. Fig. 5. 
1(3     Gums.—Surface of the Hard Palate.

  The teeth  appear to  have passed through  aper-
tures in this  membrane, and are  surrounded by it
elosely at their respective necks.
  The portion of membrane, which thus invests the
iaws, constitutes the gums; which have now acquired
a texture very different from that of the membrane,
from  which  they  were continued.  They are ex-
tremely firm  and  dense,  and very vascular.  It is
probable that their ultimate structure is not perfect-
ly understood.
  In  the desease called scurvy, they tumify and lose
the firmness  of their texture;  they acquire a livid
colour, and are much disposed to hemorrhage.
  From the  alveoli of the upper jaw, the lining
membrane is  continued  upon the palatine processes
of the upper  maxillary and palate bones, or the roof
of the mouth.
  This membrane of the palate is not quite so firm as
that of the gums, and is also less florid : it adheres
firmly to the  periosteum, and thus  is closely fixed to
the bones.  There is generally a ridge on its surface,
immediately under the sature between the two upper
maxillary bones; and some transverse ridges are also
to be seen upon it.   On the internal surface of this
membrane  are small glandular  bodies, whose  ducts
open on the surface of the palate.
  It is asserted, that this membrane has a limited de-
gree of that sensibility which is essential to the func-
tion of tasting ; and, that  if certain sapid substances
are  carefully applied to it, their respective tastes will
be perceived, although they have not been in contact
with the tongue.
  The membrane is continued from the bones above
mentioned to the soft palate, or velum pendulum pa-
lati, which is situated immediately behind them. This
soft  palate may be considered as  a continuation  of
the partition  between the  nose and mouth;  it is at- 
Soft Palate.— Uvula.            17
tached to the posterior edge of the palatine processes
of the ossa palati, and to the  pterygoid processes of
the sphenoidal bone.  Its interior structure is mus-
cular.  The  upper surface is covered by the mem-
brane  of the nose, the lower surface  by the mem-
brane which lines the mouth.
  The muscles, which contribute to the composition
of this structure,  are  the circumflexi  and the le-
vatores palati above, and the constrictores  isthmi
faucium and  palato-pharyngei below.   (See Vol. I.
page  190—191.)  Thus  composed  the soft palate
constitutes the  back  part of the partition between
the nose and mouth.   When viewed  from before,
with the mouth open, it presents towards the tongue
an arched  surface, which  continues downwards on
each side, until it comes nearly in contact with  the
edges of that organ.   On each of the lateral parts of
this arch, are two pillars, or rather prominent ridges,
which project into the mouth.  These ridges are at
some distance from each other below, and approach
much nearer  above, so that they include a triangular
space.   They are called the lateral half arches of
the palate.   Each of them is  formed by a plait or
fold of the lining membrane of the mouth, and contains
one of the two last mentioned muscles : the anterior,
the constrictor isthmi faucium ; the posterior, the pa-
lato-pharyngeus.  These muscles, of course, draw the
palate down toward the tongue when they contract.
  From  the  centre of the arch, near  its posterior
edge, is suspended the uvula, a conical body, which
varies in length from less than half an inch to rather
more  than one inch.   It is connected by its basis to
the palate ;  but  its apex is loose  and pendulous.
This body is  covered  by the lining membrane of the
mouth.  It contains many small glands, and a mus-
cle also,  the  azygos uvulae, which  arises from  the
posterior edge of the ossa palati, at the suture which
  Vol. ii.              3 
18                The Tongue.

connects them to each other, and,  passing posteriorly
upon the soft palate,  extends from the basis to  he
apex of the uvula, into which it is inserted.   By tne
action of this muscle, the length of the uvula can be
very much diminished; and when  its contraction
ceases, that body  is elongated.
  The pendulous part of the uvula can also be moved,
in certain cases, to either side.
  It is commonly supposed, that the principal use ot
this little organ is to modulate the voice ; but there
are good reasons for  believing, that it has  another
object.  It was remarked by Fallopius, (and the ob-
servation has been confirmed by many surgeons since
his time,) that the uvula may be removed completely
without occasioning  any alteration of the voice, or
any difficulty of deglutition, if the soft palate be left
entire.
  The soft palate is so flexible, that it yields to the
actions of the levatores palati, which  draw  it up so
as to close the posterior nares completely.
  It also yields to thccircumflexi or tensores, which
stretch it  so as to do away its arched appearance.
  It is therefore  very properly called the Palatum
Molle.  It is also frequently called the Velum Pen-
dulum palati, from the position which it assumes.
                   The Tongue,

  Which is a very important part of this structure,
is retained in its position and  connected with the
parts adjoining it, by the following arrangements.
  The os hyoides, which  as  its  name imports, re-
sembles the Greek letter v, or half an oval, is situa-
ted rather below the angles of the lower jaw, in the
middle of the upper part of the neck. It is  retained
in its position by the sterno-hyoidei  muscles, which
connect it to the upper part of the sternum ; by the
coraco-hyoidei, which pass to it obliquely from the 
Structure of the  Tongue.          19
scapula ;  by the thyro-hyoidei, which pass to it di-
rectly  upward from  the  thyroid  cartilage:  all  of
which connect it to parts below.  To these should be
added  the  stylo-hyoidei, which  pass to it obliquely
from behind and rather from above; the mylo-hyoidei,
which come rather anteriorly from  the  lateral parts
of the lower jaw ;  and the genio-hyoidei, which arise
from a situation  directly anterior and superior,  the
chin.  When  these muscles are at rest,  the situation
of the os hyoides is, as above described, below the
angles of the lower jaw:  when  those, in one parti-
cular direction, act while the others are passive, the
bone may be  moved  upwards or downwards, back-
wards or forwards, or to either side.   This bone may
be considered  as the basis of the tongue; for the pos-
terior extremity of that organ is attached to it; and
of course the movements of the bone must have  an
immediate  effect upon those of the tongue.
  The tongue is a flat body of an  oval figure,  but
subject to considerable changes of form.
  The posterior extremity, connected to the os hy-
oides, is commonly called  its basis; the anterior ex-
tremity,  which, when  the tongue  is quiescent, is
rather more acute, is called its apex.
  The lower surface of the tongue is connected with
a number of muscles, which are  continued into  its
substance.  This connexion is such, that the edges of
the tongue are  perfectly free and unconnected ; aw  so
is the anterior extremity for a considerable distance
from the apex towards the base.
  The substance of the tongue consists principally of
muscular fibres  intermixed with  a delicate adipose
substance.   It is connected to the os hyoides by the
hyoglossus  muscle  and also by some other muscular
fibres, as well as by a dense membranous  substance,
which  appears to  perform the  part of a ligament. 
XO          Structure of the. Tongue.

This connexion is also strengthed by the continuance
of the integuments from the tongue to the epiglottis
cartilage, to be hereafter described ; for that cartil-
age is attached by ligaments to the os hyoides.
  The tongue is thin at its commencement at the  os
hyoides : but  it soon increases in  thickness.  The
muscular fibres in its composition have been consider-
ed as intrinsic, or  belonging wholly to its internal
structure;  and extrinsic, or  existing in part outside
of this structure.   The linguales muscles are intrin-
sic :  (Vol.  I. page  189,)  they are  situated near the
under surface  of the tongue,  one on each side, sepa-
rated from each other  by the  genio-hyo-glossi mus-
cles, and extending from the basis of  the tongue  to
its apex. These muscles can be easily traced as above
described ;  but there  are also many fibres  in the
structure of the tongue, which seem to pass in every
direction, and of course are  different  from  those of
the linguales muscles.   To  these two sets of fibres
are owing many of the  immensely varied motions of
the different parts of the tongue.
  In addition to these, are the extrinsic muscles, which
originate from the neighbouring parts, and are insert-
ed and continued into the substance of the tongue.
  Among the most important of these muscles, are
those which proceed from  the chin, or  the genio-
hyo-glossi.  They are  in contact with each other;
their fibres radiate from a central point on the inside
of the chin, and are inserted into the middle of the
lower surface  of the tongue :  the insertion commen-
cing at a short distance from its apex, and continu-
ing to its base.
   As the genio-hyo-glossi  muscles  have a considera-
ble degree of thickness, they add much to the bulk of
the tongue in the middle of the posterior parts of it.
   The hyo-glossi  and the stylo-glossi, being conti- 
Papillse of the Tongue.           21
nued into the posterior and laternal parts, contribute
also to the bulk of these parts.
  The tongue, thus composed and  connected, lies,
when at rest, on  the mylo-hyoidei muscles;  and the
space between  it and these muscles  is divided into
two lateral parts  by the  above described genio-hyo-
glossi.  In the space above mentioned, is a small sa-
livary gland, of an irregular oval form ;  the  greatest
diameter of which  extends from before backwards,
and its edges present outwards and inwards.   It has
several excretory ducts,  the orifices of which form a
line on each  side  of  the tongue.  This gland is very
prominent under the tongue ; and when  the tongue
is raised  it  is  particularly conspicuous; it  is called
the Sublingual.
  The lining membrane of the mouth continues from
the inside of the alveoli of the lower jaw, which  it
covers, over the  sublingual glands to the lower sur-
face of the tongue.   In this situation it is remarkably
thin;  but, as it proceeds to the upper surface of the
tongue, its texture changes considerably ; and on this
surface it constitutes the organ of taste.
  The upper surface of the tongue, although it  is
continued from the thin  membrane above described,
is formed by a  rough integument which consists, like
the skin, of three lamina.  The cuticle is very thin;
and under it, the rete mucosum* is thicker and softer
than in other places.
  The true skin  here abounds with  eminences of va-
rious  sizes and  forms, all of which  are denominated
Papillse.   The largest of  these are  situated on the
posterior part of  the tongue, and are so arranged that
they form an angle  rather acute, with its point back-

  • M. Bichat appears to have had doubts whether the real rete mucosum
existed here.  He says that he could only perceive a decussation of vessels
io the intervals of the papillse, which, as he.supposes, occasioned the florid
colour of the tongue. 
22           Papillse of the Tongue.

wards.   They are commonly nine in number: they
resemble an inverted  cone; or,  are  larger at their
head than  their basis.   They are situated in pits or
depressions, to the  bottoms of which they are con-
nected.  In many of them there are follicles, or per-
forations, which  have occasioned them to  be regard-
ed as glands.  They are called Papillse  Maxima,
or Capitatse.
   The  papillas, next in size, are denominated fungi-
form by some anatomists, and Mediae or  Semilenti-
culares by others.  They  are nearly cylindrical in
form, with their upper extremities  regularly round-
ed.   They are scattered over the upper surface of
the  tongue, in almost  every part of  it, at irregular
distances from each other.
   The  third class  are called conoidal   or  villous.
They are very  numerous,  and occupy the greatest
part of the surface of the tongue.   Although they
are called conoidal, there is a great difference in their
form ;  many  of  them  being irregularly angular  and
serrated, as well as conical.
   Soemmering and other German anatomists consider
the  smallest papillae as a fourth class, which they call
the filiform : these lie between  the others.
   It is probable that these papillae are essential parts
of the organ of taste ;   and their structure is of course
an interesting object of inquiry.
   The nerves of the tongue have been traced  to the
papillae, and  have been compared by some anatomists
to the stalk of the apple, while the papillse resembled
the fruit: but their ultimate termination does not ap-
pear to have been ascertained.*

   * In the explanation of the plates, referred to in the following sentence,
Soemmering observes, that when the fibrillae of the lingual nerve of the
fifth pair are traced to  the papillae of the second class, they swell out into
 a conical form ; and these nervous cones are in such close contact with
 each other, that the point of the finest needle could not be insinuated into
 the papillae-without touching a nerve. 
           Blood vessels of the Tongue.         23

  Soemmering has lately published some elegant en-
graved  copies of drawings of these papillae, when
they were magnified twenty-flve times;  from which
it appears that a very large number of vessels, parti-
cularly of arteries, exist in them.   These vessels are
arranged in a serpentine direction, and are prominent
on the surface; but  they appear doubled,  and the
most prominent part is the doubled  end.—This ar-
rangement of  vessels is perceptible  on  the sides of
the tongue, as well as on the papillse.
  Behind the large  papillse is a foramen,  first de-
scribed  by Morgagni, and  called  by him Foramen
Caecum.  It  is the  orifice of  a cavity which is not
deep ; the excretory ducts of  several mucous glands
open into it.
  On the upper surface of the tongue, a groove is
often to be seen, which is called the linea mediana,
and divides it into two  equal lateral parts.   Below,
the lining membrane of the mouth, as it is continued
from the lower jaw to the tongue, forms  a  plait,
which acts as a ligament, and  is called the frsenum
linguss.  It is attached to the middle of the tongue,
at some distance behind the apex.
   The  tongue is well  supplied with blood vessels,
which are  derived from the  lingual branch of the
external carotid on each  side.  This  artery passes
from the external carotid, upwards, inwards, and
forwards, to the body of the tongue.  In this course
it sends off several small arteries  to the contiguous
parts, and  one, which  is spent about the  epiglottis
and the adjoining parts, called the Dorsalis Linguae.
About the anterior edge of the hyo-glossus muscle,
it divides into two  large  branches: one of which,
called the Sublingual,  passes  under the tongue be-
tween the genio-hyoglossus and the sublingual gland,
and extends near to the symphysis of the upper jaw;
sending branches to  the sublingual gland, to the 
24         Blood vessels of the Tongue.
muscles under the tongue, to the skin, and the lower
lip.   The other is  in the substance of the tongue,
on the under side near the surface, and extends to
the apex.
  The veins of this organ are not so  regular as the
arteries: they communicate with the external  jugu-
lar ; and some of them  are always very conspicuous
under the tongue : these are called ranular.
  It is to be observed, that the vessels on each side
have but little connexion with each other ;  for those
of one side may be injected while the others continue
empty.
  The tongue is also well supplied with nerves, and
derives them from three  different sources on  each
side, viz. from  the fifth, the eighth, and ninth pairs
of the head.
  The lingual portion of the third branch of the fifth
pair,  passing under the  tongue,  enters its substance
about the middle, and forms many minute branches,
which pass  to  the papillse of the fore part of the
tongue.
  The glossopharyngeal portion of the eighth pair,
sending off several branches in its course, passes to
the tongue  near its basis,  and  divides into  many
small  branches, which are spent upon  the sides and
middle of the root of the tongue, and also upon the
large  papillse.
  The ninth pair of nerves  are  principally appro-
priated  to the tongue.   They pass on each side to
the most fleshy part of it, and  after sending  one
branch to the mylo-hyoideus, and  another to com-
municate with the lingual branch of the fifth pair,
they are spent principally upon the genio-glossi, and
linguales muscles.
  The tongue answers  a  threefold purpose.   It  is
the principal organ of taste.   It is a very important
agent in the articulation of words; and it assists in 
Salivary Glands.
25
those operations upon  our food, which are perform-
ed in the mouth.
               The Salivary Glands.
  The  salivary glands have such an  intimate  con-
nexion with the mouth that they may  be described
with it.*
  There are  three  principal  glands  on each side :
the Parotid, the Submaxillary and  the Sublingual.
They are of a whitish  or pale fl; sh-colour, and are
composed of  many  small  united  masses or lobuli,
each  of  which sends a small excretory duct  to  join
similar ducts from the  other lobuli, and thereby form
the great duct of the gland.
  The Parotid is much larger than the other glands.
It occupies a  large  portion of the vacuity between
the mastoid  process  and  the posterior parts of the
lower jaw.  It extends from the ear and the mastoid
process over a portion of the  masseter muscle,  and
from the zygoma  to the basis of the  lower jaw.   Its
name is  supposed, to  be  derived from two Greek
words which signify contiguity  to the ear.  It is of a
firm consistence.   It receives branches from the ex-
ternal carotid artery  and from its facial branch.
  From  the anterior  edge of this gland, rather above
the middle, the great duct proceeds anteriorly across
the masseter muscle;  and, after it has passed over
it, bends inward  through the adipose  matter of the
cft< ek to the  buccinator muscle, which  it perforates
obliquely and opens on  the  inside of the cheek  op-
posite to the interval between  the second and third
molar teeth of the upper jaw.   The aperture of the
duct is rather less than the  general  diameter  of it,
and  this circumstance  has  the effect of  a valve.
When  the duct  leaves the parotid,  several small
glandular bodies  called  sociae  parotidis, are often
  * For a general account of glands, see the appendix to this volume.
  Vol. ii.              4 
26      Parotid arid Submaxillary Glands.

attached to it, and their ducts communicate with  it.
The main duct is  sometimes called after Steno, who
first described it.
  When the  mouth is  opened wide, as in  gaping,
there is often  a jet of saliva from it into the mouth.
  The parotid gland furnishes the largest proportion
of saliva.
  It covers the nerve called Portio  Dura,  alter it
has emerged from the foramen stylo-mastoideum.
  The second gland is called the Submaxillary. It is
much smaller than the parotid,  and rather round in
form.   It  is  situated immediately within  the angle
of the lower jaw,  between it, on the outside, and the
tendon  of  the digastric muscle and the ninth pair of
nerves  internally.   Its posterior extremity  is con-
nected  by cellular membrane  to the parotid gland ;
its  anterior portion lies  over  a  part of  the mylo-
hyoideus muscle ; and from it proceeds the excretory
duct, which is of considerable length, and passes be-
tween the mylo-hyoideus and the genio-gbssus mus-
cles along the under and inner edge of  the sublin-
gual gland.   In  this course the duct  is sometimes
surrounded with  small glandular bodies, which seem
to be appendices  of the sublingual gland.   It termi-
 nates under the tongue,  on the side of the fraenum
linguae, by a small  orifice which sometimes forms a
 papilla.*
   The orifice is often smaller than the duct;  in con-
 sequence of which, obstruction frequently occurs here,
 and produces the disease called ranula.
   The  sublingual  gland, which  has  already  been
 mentioned, lies so  that, when  the tongue is  turned

   * Lassus informs us that Oribases, afterwards all the Arabians, and sub-
 sequently Guy De Chauliac, Lanfranc,  Achillini Berenger De Carpi,
 Charles Etienne, Casserius and several others have given the description
 of these salivary ducts, notwithstanding which Wharton, a  physician of
 London, attributed to himself the discovery of them on the bullock in
 1656.—Ed. 
           Sublingual Gland.—Saliva.         27

up, it can be seen protruding into the cavity of the
mouth, and covered by the lining membrane, which
seems to keep it fixed in its place.  It lies upon the
mylo-hyoideus, by the side of the genio-hyoideus ;
and is rather oval  in  form and flat.   Its  greatest
length is from before backwards;  its position is rather
oblique,  one edge being placed obliquely inwards and
upwards, and  the other  outwards and  downwards.
It has many  short  excretory ducts, which open  by
orifices  arranged  in a line on each  side : they are
discovered with difficulty  on  account of their small
size, and sometimes amount to eighteen or twenty in
number.  In  some few instances, this gland sends off
a single duct, which communicates with  the duct of
the submaxillary gland.
  The  salivary fluid secreted by these glands is  in-
odorous, insipid, and limpid, like water;  but much
more  viscid,  and of greater specific gravity.  Water
constitutes at least four-fifths of its bulk ; and animal
mucus one-half of its solid contents.  It also contains
some aloumen, and several saline substances : as the
muriate of soda, and the phosphates of lime, of soda,
and of ammonia.
  It is  probable that  this fluid  possesses a solvent
power with respect to the  articles of  food.
  There are small glandular bfdies,  situated  be*
tween the masseter and buccinator muscles, opposite
to the last molar tooth of the upper jaw,  whose na-
ture is not well understood :  they are called Gland-
idx Molares.

      The motions of the tongue are very intelligible to a
        person who  has a preparation of the lower jaw  be-
        fore him, with the tongue in its natural situation, and
        the muscles which influence  it, properly dissected.
        Its complicated  movements  will appear the neces-
        sary result of the action of those  muscles upon it,
        and the os hyoides ; and also upon the larynx, with 
2ft          Observations on the Tongue.
        which  the os hyoides is connected.  The muscular
        fibres of the tongue itself are also to be taken into
        this view, as they act a very important part.
      Although the tongue appears very necessary in a me-
        chanical point of view, to the articulation of many
        words, yet there are cases where it has been entire-
        ly deficient, in which the parties thus affected, have
        been able to speak very well in general, as  well as
        to distinguish different tastes.*
      The tongue is also a very delicate organ of touch.—
        We can perceive the form of the teeth, and the atate
        of the surface of the mouth, more accurately by the
        application of the tongue than of  the  lingers.
      On the three nerves which go to the tongue, it is ge-
        nerally supposed that the lingual portion of the third
        branch of the fifth pair is most  immediately con-
       ' cerned in the function of tasting, as it passes to the
        front part of  the surface of the tongue.  The glos-
        sopharyngeal are probably concerned in the same
        function on the  posterior part, while  the ninth pair
        of nerves seems principally spent upon the muscu-
        lar parts of the  organ.
      It is obvious that the tongue is most copiously supplied
         with nerves.   This probably accounts for the great
         facility of its motions,  and  the  power of continu-
         ing them.

  *  There is a very interesting paper on this  subject, in the Memoirs of
the Academy of Sciences for the year 1718, by Jussieu; in which he de-
scribes the  case of a female, fifteen years old, examined by himself, who
was born without a tongue. In this paper he refers to  another case, de-
scribed by Rolland, a surgeon of Saumur, of  a boy nine years old, whose
tongue was destroyed by gangiene. In each of these cases the subject was
able to articulate  very well, with  the exception of a few letters; and also
enjoyed the sense of taste. 
CHAPTER III.
                OF THE THROAT.

  To avoid circumlocution, the word throat is used
as a general term to comprehend the structure which
occurs behind the  nose  and mouth,  and above the
OBsophagus and trachea.   This structure consists,
  1st. Of the parts immediately  behind  the mouth,
which constitute the Isthmus of the Fauces :
  2nd.  Of the parts which form the orifice of the
windpipe, or the Larynx ;—and
  3d. Of the muscular bag, which forms the cavity
behind the nose  and mouth that terminates  in the
oesophagus, or the  Pharynx.

                    SECTION I.

          Of the Isthmus of the Fauces.

  In the back part of the mouth, on each side, are to
be seen the  two  ridges or half arches, passing from
the soft palate of the root of the tongue, mentioned
in page 17, and said to be formed  by plaits  of the
skin containing muscular fibres. . The anterior plait,
which contains the muscle called Constrictor  Isthmi
Faucium, passes directly from the side of the root of
the tongue  to the palate,  and terminates  near the
commencement  of the  uvula.  The posterior plait
runs from the palate obliquely downwards and back-
wards,  as it contains the palato-pharyngeus muscle,
which passes from  the palate to the upper and poste-
rior part of the  thyroid cartilage.
   In the triangular space between  these  ridges  is
situated a glandular body, called the Tonsil Amyg- 
30             Tonsils—Epiglottis.

dala.  This gland has an oval form,  its longest dia-
meter extending from above downwards.   Its surface
is rather convex, its natural colour is a pale red.  On
its surface are the large orifices of many cells of con-
siderable size, which  exist throughout the  gland.
These cells often communicate with each  other,  so
that a probe can be passed in at one orifice and out
at the other.
  Into these  cells open  many mucous ducts, which
discharge the  mucus of the throat, for  the purpose
of lubricating the surface,  and facilitating  the trans-
mission of food.
  Tlie epiglottis, or fifth cartilage  of the  larynx, is
situated at the root  of the  tongue, in  the middle,
between the tonsils.   The part which is in sight is
partly oval in form,  and of a whitish  colour.   Its
position,  as respects  the tongue, is  nearly  perpendi-
cular, and its anterior surface rather convex.
  The membrane continued from  the  tongue over
the  epiglottis  is so arranged that  it forms a plait,
which extends from  the  middle of the  root  of the
tongue along   the  middle of the  anterior  surface of
the epiglottis, from its base upwards.
  On each side of this plait, or frsenum,  at the junc-
tion of the surfaces of the tongue and of the epiglot-
tis,  there is often a depression, in  which small  por-
tions of food sometimes remain;  and a small fraenum,
similar to that above described, is sometimes seen on
the outside of each of these cavities.
  The epiglottis is situated  immediately before the
opening into the larynx.
  The above  described parts can be well ascertained
in the living  subject, by a  person who has a general
knowledge of the structure.   Thus, looking into the
mouth, with the tongue depressed,  the uvula and soft
palate are in full  view above, and the  epiglottis is
very perceptible below ; while the two ridges or la- 
Of the Larynx.
31
teral half arches can be seen on each side, with the
tonsil between them.

                    SECTION II.

                 Of the Larynx.

   In this structure are five cartilages, upon which
its form and stength depends, viz. the Cricoid, the
Thyroid, the two Arytenoid, and the  Epiglottis.
These cartilages are articulated  to each other, and
are supplied with muscles by which certain  limited
motions are effected.
   The basis of the structure is a cartilaginous ring,
called the cricoid cartilage, which may be considered
as the commencement of the windpipe.
   It may be described  as an  irregular section of a
tube : its lower edge,  connected  with the windpipe,
being nearly  horizontal when the body is erect; and
the  upper edge very  oblique, sloping from  before,
backwards and upwards :  in  consequence of this, it
has but little depth before, but is eight or nine lines
deep behind.
   The Thyroid cartilage is a single plate, bent in such
manner that it forms an acute angle with two similar
broad surfaces on each side of it.   It is so applied to
the cricoid cartilage, that the lower edge of the angu-
lar part is at a small distance above the front part of
that cartilage,  and connected  to it by  ligamentous
membrane: while its broad sides are applied to it
laterally, and  thus partially enclose it.
   The upper edge of the angular part  of the thyroid
cartilage forms a notch ; and the natural position of
the cartilage  is such, that this part is very prominent
in the neck ;  it is called the Pomum Adami.
   Both the upper and lower  edges  of the  thyroid
cartilage  terminate  posteriorly in processes, which 
32    Arytenoid Cartilages and Ligaments.

are called Cornua.  The two uppermost are longest:
they are joined by ligaments to the extremities of the
os hyoides.   The  lower and shorter processes are
fixed to the cricoid cartilage. The thyroid cartilage,
therefore, partly rests upon the cricoid cartilage be-
low, and is attached to the  os hyoides above.  It is
influenced by the  muscles which act  upon the  os
hyoides, and also by some muscles which  are insert-
ed into itself.  It is moved obliquely downwards and
forwards, in  a slight degree, upon the cricoid cartil-
age by a small muscle, the crico-thyroideus, which
arises from that cartilage and is inserted into it.
  The Arytenoid cartilages are two  small bodies of a
triangular pyramidal form, but slightly curved  back-
wards.   They are placed upon the upper and poste-
rior edge of the cricoid cartilage, near to each other;
and their upper ends, taken together,  resemble the
mouth of a  pitcher or  ewer;  from which  circum-
stance their  name is derived.  Their bases are broad 5
and on their lower surfaces  is a cavity,  which cor-
responds with the convex  edge of the cricoid cartil-
age, to which they are applied.   At these places, a
regular moveable articulation is formed, by  a capsu-
lar ligament between  each of these cartilages and the
cricoid,  in consequence of which they can  be incli-
ned backward or forward, inward or outward.
   From the anterior part of each of these cartilages,
near the base, a tendinous cord passes forward, in a
direction which is horizontal when the body is erect,
to the internal surface of  the  angle of the  thyroid.
These ligaments  are not  perfectly parallel to each
other; for they are nearer before than behind. The
aperture between them is from two  to five lines wide
when the muscles are not in action ;  and this aperture
is the orifice of the windpipe : for the exterior  space,
between these ligaments  and  the  circumference of
the thyroid,  is closed up by membrane and muscle. 
                  Epiglottis.                   3."}

At a  small  distance above these ligaments are two
others,  which also pass from the arytenoid  to the
thyroid cartilages.  They are not so tendinous and
distinct as the first mentioned, and  cannot be drawn
so tense by  the muscles of the arytenoid cartilages.
They are also situated at a greater distance from each
other, and thus form  a large aperture.
   On the external side  of the  upper  extremity  of
each of the  arytenoid cartilages, and nearly in con-
tact with it, is a small cartilaginous body, not so large
as a grain of wheat, and  nearly oval in form.  These
are connected firmly to the arytenoid cartilages, and
are called their appendices.   Being in the margin of
the aperture of the larynx, they have an effect upon
its form.
   The  arytenoid  cartilages  are the posterior parts
of the  larynx: the Epiglottis, which has  already
been mentioned, is the anterior.  When this  carti-
lage is  divested  of its membrane,  it is  oval  in its
upper extremity, and rather angular below, termi-
nating in a long narrow  process, which is like the
stalk of a leaf.  It is firmly  attached to the  internal
surface  of the angular part  of  the  thyroid by this
lower process; and, being placed in a perpendicular
position, one of its broad surfaces is anterior  towards
the tongue, and the other posterior, towards the open-
ing of the windpipe.
   It is attached to the os hyoides by dense cellular
texture or ligament, and  to the tongue by those plaits
of the membrane of the mouth, which have been al-
ready described.
   It is elastic, but more flexible than the other car-
tilages ; being somewhat different in its structure.—
Its surface is perforated by the orifices of many mu-
cus ducts.
   There is a small space between the lower  part of
this cartilage, and the upper  part of the thvroid and
   Vol.  ii.                5 
34
jRima Glottidis.—Glottis.
the ligamentous membrane passing from it to the os
hyoides.   In this is a substance,  which appears to
consist of glandular and of adipose matter.   It is sup-
posed that some of the orifices  on the lower part of
the epiglottis communicate with this substance.
  In the erect position of  the body, the epiglottis is
situated rather higher up  than the  arytenoid carti-
lages, and at the distance of ten or twelve lines from
them.
  The membrane which covers the epiglottis, is  ex-
tended from each side of it to the  arytenoid carti-
lages ; and being continued into the cavity of the la-
rynx, as well as upon  the  general surface  of  the
throat, it is necessarily doubled : this doubling forms
the lateral margins of the orifice of  the cavity of the
larynx.   In these folds  of the  membrane are seen
very  delicate muscular  fibres,  called the Aryteno-
epiglottidei.
  The membrane continues down  the cavity of  the
larynx, and, covering the upper ligaments, pene-
trates into the vaeuity between  them and the lower
ligaments, so as to form a cavity on each side of  the
larynx, opening between the two  ligaments, which
is called the  Ventricle of Morgagni.  The shape of
these cavities is oblong.   Its greatest length extends
from behind forward, on  each  side of the opening
into the windpipe formed by the  two lower or prin-
cipal  ligaments; so that when the larynx is removed
from the subject, upon  looking into it from  above,
you perceive three apertures: one in the  middle,
formed  by the two lower ligaments;  and  one on
each side of it,  between the  lower and upper liga-
ment, which is the orifice of the ventricle of Mor-
gagni.
   The aperture between the two lower ligaments is
called the Bima Glottidis, or Chink of the Glottis;
the upper aperture, formed by the fold of the mem- 
        Arteries and Nerves of the Larynx.     3o

brane extending from the epiglottis to the arytenoid
cartilages, may be termed Glottis.
  If the windpipe is divided near the larynx, and
the larynx inverted, so that  the rima glottidis, may
be examined from below, the structure appears still
more simple : it resembles a septum fixed abruptly
in the windpipe, with an aperture in it of the figure
of the rima glottidis.
  The anterior surface of the two arytenoid cartila-
ges is concave.  This concavity is occupied  in each
by a glandular substance, which lies between the car-
tilage and the lining membrane; and  extends itself
horizontally, covered by the upper  ligament of the
glottis.   The nature of these bodies is not perfectly
understood;  but they  are  supposed  to  secrete
mucus.
  The membrane, which lines the cavity of the gfot-
tis being continued from the mouth and throajb re-
sembles the membranes which invest those p,vts.  In
some places, where it is in close contact witfe the car-
tilages, it appears united with  the  per*^hondrium,
and acquires more firmness and densif*
  The general motions of the laryn* are very intel-
ligible to those who are acquainted with the muscles
which are connected with the thyroid cartilage, and
which move the os hyoides.  ^hey take place par-
ticularly in  deglutition, and *n some modifications of
the voice;  and also in voicing.
  The motions of the  particular cartilages on each
other can also  be well understood,  by attending to
the origin and insertion of the various small muscles
connected with the?.  The most important of these
muscles are  the  ^rico-arytenoidei postici and late-
rales, the thyrenarytenoidei, the arytenoidei obliqui,
and  the aryte»oideus transversus.   The effects of
their actions appear to be the dilating or contracting 
36      Arteries and Nerves of the Larynx.

the rima glottidis, and relaxing or extending the li-
gament"' which form it.
  The arteries of  the  larynx  are derived from two
sources,  viz.  the  superior  thyroid,  or laryngeal
branch of the  external carotid ;  and  the  thyroid
branch of t*ie  subclavian.
  The nerves of the larynx also come to it  in  two
very dift'erent directions on each  side.   It receives
two branches from  the par vagum :  one which leaves
that nerve  high  up in the neck, and is called the
Superior  Laryngeal branch ; and another which
proceeds from it  after it has passed  into the cavity
of the thorax,  and is called from  its  direction  the
Recurrent.
The extreme irritability of the glottis is unequivocally
  demonstrated by the cough which is  excited when a
  drop of water, or any other mild liquid, or  a crumb
  oVbread  enters  it.   Notwithstanding this,  a flexi-
  hleN^ube, or catheter, has several times been passed
  i itoNbe windpipe through the rima glottidis, and
  been enVjred by the patient a considerable time.
The cough, \hicli occurs when these parts are  irritated,
  does not appear to arise  exclusively from the irrita-
  tion of the  n\mbrane within  the  glottis;  for, if it
  were so, mucii^;110US  substances,  when swallowed
  slowly,  could notwpend it,  Their  effect  in reliev-
  ing cough is univerMiv known; and  as they are only
  applied to the surfac\pXterior  to the glottis, it is evi-
  dent that the irritation\f this  surface must also pro-
  duce coughing.        \
 Several curious experiments l^ve been made  to deter-
   mine the effect of dividing >he different nerves which
   go to the 1 irynx ; by which\t  appears that the re-
   current branches supply parts\vhich are essentially
   necessary to  the formation of \\ie voice  whilst the
   laryngeal branches  supply part* which' merely in-
   fluence its modulation, or tone.   S^> \lr. Haiehton'a
   Essay on this subject:  Memoirs of fc^e Medical So-
   ciety of London, Vol. HI. 
       The Thyroid Gland.—The Pharynx.    37

                The Thyroid Gland

  May be described  here, although a part of it is
situated  below the larynx.
  This body consists  of  two lobes, which are united
at their lower extremities by a portion which extends
across the anterior  part  of the windpipe.   Each lobe
generally rises upwards  and backwards from  the se-
cond  cartilaginous ring of the windpipe over the cri-
coid cartilage  and a portion of the  thyroid.   It lies
behind the sterno-hyoidei and sterno-thyroidei mus-
cles.   It is of a reddish-brown colour, and appears
to consist of a granulous substance ;  but its ultimate
structure is not understood.  It is plentifully suppli-
ed with  blood, and receives two arteries on each side:
one from the laryngeal branch of  the external caro-
tid :  and the other from the thyroid  branch  of the
subclavian.
   Notwithstanding this large supply of blood, there
is no  proof that it performs  any secretion;  for al-
though several respectable anatomists have supposed
that they discovered  excretory ducts passing to the
windpipe,  larynx, or  tongue,  it is  now  generally
agreed that such excretory ducts are not to be found.
 Several  instances  have however  oocurred, in which
air has  been forced,  by violent  straining, from the
windpipe into the  substance of this gland.*

  * There are tw> membranous expansions in  the neck which should be
noticed in its dissection.  Tie first called Fascia Superficialis lies imme-
diately beneath the skin, may be  considered as  a continuation of the fascia
superficial^ abdominis, and is strongly connected to the base of the lower
jaw, being also spread over the parotid gland.  It is not very distinct in all
subjects.  The second is called the Fascia Profunda Cervicis;  it extends
from the larynx and thyroid  gland to the upper part of the sternum and
 first ribs, the j;reat vessels, &c.  of the superior mediastinum are placed
 immediately below it.—Ed. 
38         Structure of the Pharynx.
                    SECTION III.

                 Of the Pharynx.

   The pharynx is a large muscular bag, which forms
the great cavity behind the nose and mouth that ter-
minates in the oesophagus.
   It has been  compared to a  funnel, of which the
oesophagus is the pipe :  but it differs from a funnel
in this respect, that it is incomplete  in front, at the
part occupied by the  nose and mouth and larynx.
   It is connected above, to  the cuneiform process of
the occipital bone, to the pterygoid processes of the
sphenoidal, and  to both the  upper and lower maxil-
lary bones.  It is in contact with the cervical verte-
bra behind; and, opposite to the cricoid cartilage,
it terminates in the oesophagus.
   If the pharynx and oesophagus be carefully dissect-
ed and detached  from the vertebrae,  preserving the
connexion of the pharnx witli the head ; and the  head
then be separated  from  the body, by dividing the
articulation of the atlas and the os occipitis, and cut-
ting through  the soft parts  below the larynx ; the
resemblance to a funnel will  be very obvious.
   In this situation,  if an incision  be made  from
above downwards though the  whole extent of the
posterior part of the pharynx, the communication of
the nose, mouth, and windpipe,  with this cavity,
will be seen from behind at one view.
   The openings into the nose,  or the posterior nares,
appear uppermost.  Their figure is irregularly oval
or pblong;  they are separated from each other by a
thin partition, the vomer.   Immediately behind, on
the external  side of  each of  these  orifices, is the
Eustachian tube.
   The  soft  palate will appear  extending  from the
lower boundary of the  posterior nares, obliquely 
Structure of the Pharynx.          39
backwards and downwards, so as nearly to close the
passage into the mouth.  The uvula hangs from it;
and, on each side of the uvula, the edge of the palate
is regularly  concave.
  Below the palate, in the isthmus of the fauces, are
the ridges  or half-arches, and  the  tonsils between
them.  The half-arch which  presents first,  in this
view, runs obliquely downward  and backward,  and
not parallel  to the other.
  Close  to  the  root of the tongue is the epiglottis
erect; and, immediately adjoining it, is an aperture
large enough  to admit the end of a middle-sized
finger.   This aperture  is widest at the extremity
next to the  epiglottis, and  rather  narrower at the
other extremity : it is the glottis or opening of the
windpipe.  When  the larynx  is elevated, the epi-
glottis can  be readily depressed so  as  to cover it
completely.
   The extremities of the  arytenoid  cartilages, and
their appendices, may be recognised at the posterior
edge of  the glottis.   At a short distance below this
edge, the oesophagus begins.
   The Pharynx is composed of the membrane con-
tinued from the nose and mouth internally, and of  a
stratum  of  muscular fibres externally. The internal
 membrane is very soft and  flexible, and perforated
by many muciferous ducts.   The  surface which  it
forms is  rather rough, owing  to the mucous glands
which it covers.  It has a red colour, but not  so deep
as that of some other parts.   It is connected to the
 muscular stratum bv  a loose cellular membrane.
   The   muscular coat consists of three different por-
 tions, which are considered as so many distinct mus-
cles.
   The  fibres of each of these  muscles  originate on
 each side, and run in an oblique direction to  meet in 
  40         Structure of the Pharynx.

  the middle, thus forming the posterior external sur«
  face of the dissected pharynx.
    The fibres of the upper muscle originate Irom the
  cuneiform  process of  the  occipital  bone, fr™ the
  pterygoid  processes of the os sphenoides, and from
  the upper and  lower  jaws, near the last  dentes mo-
  lares, on each side.  They unite in a  middle line  in
  the back of the pharynx.
    The fibres of the middle muscle originate pnnci-
* pally from the  lateral  parts of the os hyoides, and
  from the ligaments which  connect  that  bone to the
  thyroid cartilage.  The superior fibres run obliquely
  upwards, so as to cover a part of the first mentioned
  muscle, and terminate in the cuneiform process of the
  occipital  bone; while  the other fibres  unite  with
  those of the opposite side  in the middle  line.
    The fibres of the lower muscles arise from the thy-
  roid and the cricoid cartilages, and terminate also in
  the middle line.  Those which are superior, running
  obliquely upwards; the inferior, nearly in  a trans-
  verse direction.
    It is obvious, from  the origin  and  insertion  of
  these fibres, that the pharynx must have the power
  of contracting  its dimensions in every  respect;  and,
  particularly, that its  diameter may be  lessened  at
  any place ; and that the whole may be   drawn up-
  wards. 
SYSTEM OF  ANATOMY.

                PART VII.
                OF THE THORAX.

  Before the thorax is described, it will  be in or-
der to consider the

                    Mammae ;
  Or those glandular bodies, situated on the anterior
part of it, which, in  females, are  destined to the se-
cretion of milk.
  These glands lie between the skin and the pecto-
ral muscles, and are attached to the surfaces of those
muscles by cellular membrane.
  They  are  of a  circular form; and consist of a
whitish firm substance, divisible into small masses or
lobes, which are composed of smaller portions or lo-
buli.  Between these glandular portions a great deal
of adipose matter is so diffused, that it constitutes a
considerable part of the bulk of the mammae.
  The gland, however, varies greatly in thickness in
the same person at different periods of life.
  The mammae become  mueh enlarged about the
age of puberty.  They are also  very large during
pregnancy  and lactation; but  after  the  period  of
child-bearing, they diminish considerably.   They
are supplied with blood by the external and  internal
  Vol. ir.              6 
42
Mammae.
mamary arteries, the branches of which enter  them
irregularly in several different places.
   The  veins correspond with the arteries.
   From the  small  glandular  portions  that compose
the mamma,  fine excretory tubes arise, which  unite
together and form the great lactiferous ducts of the
gland.   These ducts proceed in a radiated manner
from the circumference to the  centre, and terminate
on the surface of the nipple.*
   They are commonly about fifteen in number, and
vary considerably in size : the largest of them being
more than one-sixth of  an inch in diameter.
   They can  be very readily injected by the orifices
of the  nipple, from a pipe filled with mercury, in
subjects who have died during lactation or pregnan-
cy;  but they are very small in  subjects of a differ-
ent description.
   It has been asserted by respectable anatomists, that
these ducts communicate freely with each other ; but
they do not appear to do so :  each duct seems to be
connected with its proper branches only.f
   Haller appears to have entertained the remarkable
sentiment, that some of the  ducts originated in the
adipose matter about the gland, as well as in the glan-
dular substance.J
   The  papilla, or* nipple, in which these ducts ter-
minate, is in the  centre of the mamma : it  consists of
a firm elastic substance, and  is nearly cylindrical in
form.   It is rendered  tumid by irritation, and by
certain  emotions.
   The  lactiferous ducts terminate upon its extremi-
ty.  When it is elongated they can freely discharge


.v* DtSCri.ued m the 16th centuT> by Charles Etienne, VesaliuB and Pos-
tnms, but their uses were unknown.—Ed.
Meckel EdDinbur8h Medical Commentaries, vol. 1. page 31—a paper by
  % Elements Physiologiae, Tom. 7, Pars 11, page 7. 
Mammae.
43
their contents; but when it contracts, this discharge
is impeded.
  The skin  immediately around the nipple is of a
bright red colour in virgins of mature age.  In preg-
nant women  it is  sometimes almost black; and in
women who  have borne children it is often brownish.
It abounds with sebaceous glands,  which form small
eminences on its surface.
  This gland  exists in males,  although  it is very
small.   In boys, soon after birth,  it has often been
known to tumefy and become very painful, in conse-
quence of the secretion and accumulation of a whitish
fluid, which can be discharged by  pressure.  It also
sometimes swells and is  painful,  in males at the  age
of puberty.
  There have been some  instances in which it  has
secreted milk  in adult males;  and a few  instances
also in which it has been affected with cancer, in the
same sex.
  The mamma is plentifully supplied with absorbent
vessels, which pass from it to  the  lymphatic glands
in the axilla.
  Its nerves are principally derived from  the  great
plexus formed by the nerves of the arm. 
                 CHAPTER I.

    OF THE GENERAL CAVITY OF THE THORAX.

                    SECTION I.

    Of the form of  the Cavity of the  Thorax.

  The osseous structure of the thorax is described
in vol. i. page 94.   The cavity is completed by the
intercostal muscles, which close the vacuities between
the ribs; and by the diaphragm, which fills up the
whole space included within its lower margin.
  If we  except the apertures of  the diaphragm,
which are completely occupied by the aorta, the vena
cava, and the oesophagus, &c. the only  outlet of this
cavity is  above : it is formed  by the upper ribs, the
first dorsal  vertebra,  and the  sternum.   The figure
of this aperture is between that of the circle and the
oval; but it is made  irregular by the vertebra, and
by the upper edge of the sternum.
   Wrhen the superior  extremities and the muscles
appropriated to them are removed, the external figure
of the thorax is conical; but the cavity formed by it
is considerably influenced by  the  spine, which pro-
trudes into it;  while the ribs, as they  proceed from
the  spine, curve backwards,  and  thus  increase its
prominency in the cavity.
   The diaphragm has a great effect upon the figure
of the cavity of the thorax. It protrudes into it from
below, with a  convexity of such form that it has been
compared to an inverted bowl; so that, although it
arises from the lower margin  of the thorax, the cen-
tral parts of it are nearly as high as the fourth rib. 
Pleurae.
45
  The  position of the diaphragm is also  oblique.
The anterior portion of its margin, being connected
to the seventh and  eighth ribs, is much higher than
the posterior portion, which is attached to the eleventh
and twelfth.
  In consequence of the figure and position of the
diaphragm, the form of the cavity of the thorax re-
sembles that of the  hoof of the ox when its posterior
part is presented forwards.

                    SECTION II.

        Of the arrangement of the Pleurae.

  The thorax contains the  two lungs  and heart, as
well as several very important parts of smaller size.
  The lungs occupy the greatest part of the cavity;
and to each of them is appropriated a complete sac,
called  Pleura, which  is so arranged that it covers
the surface of the lungs, and is continued from it to
the contiguous surface  of the thorax, which it lines.
After covering the  lung, it is extended from it to the
spine  posteriorly,  and the sternum  anteriorly: so
that in  tracing the  pleura in a circular  direction,  if
you begin at the sternum, it proceeds on the inside
of the ribs to the spine; at the  spine it leaves the
surface of the thorax, and proceeds directly forwards
towards the sternum.   In its course  from the spine
to the sternum, it soon meets with the great branch
of the windpipe and the blood vessels, which go to
the lung:  it continues on these vessels and round the
lung until it arrives at the  anterior side of the ves-
sels, when it again proceeds forwards until it arrives
at the  sternum.  Each sac being arranged in the
same way, there is  a part of each extended from the
spine to the sternum.  These two lamina, form the
great vertical septum of the  thorax, called Mediasti-
num.  They are situated at some distance from each 
46
Mediastinum.
other;  and the heart, with its investing membrane or
pericardium, is placed between them.
   The  pericardium is also a complete sac or  blad-
der, which, after  covering  perfectly the surface of
the heart,  is extended from it so as to form a sac,
which lies  loose about it,  and appears to contain it.
This loose  portion adheres to those  parts of the la-
mina  of the mediastinum  with  which it  is contigu-
ous ;  and thus three chambers are formed within the
cavity of the thorax:  one for each lung, and one for
the heart.
   The  two lamina of the pleura,  which constitute
the mediastinum, are at different distances from each
other, in different  places.   At the upper part of the
thorax,  they approach each other from the  internal
edges of the first ribs; and, as these include a space
which is nearly circular,  the vacuity between  these
lamina is necessarily of that form, at its  commence-
ment above.
   Here, therefore, is a  space  between them above,
which is occupied  by  the great transverse vein that
carries the  blood of the left subclavian and the left
internal jugular to  the superior cava; by the trachea;
by the oesophagus; and by the subclavian and  caro-
tid arteries, as they rise from the curve of the aorta.
This space  is bounded below by the above mentioned
curve of the aorta.
  The  heart and  pericardium are so  placed that
there is a small distance between  them and the ster-
num : in this space the two lamina  of the mediasti-
num are very near to each other ; and cellular sub-
stance intervenes between  them.  This portion of the
mediastinum is called  the Anterior Mediastinum.
   Posteriorly, the  heart and pericardium are also at
a small distance from the spine;  and here the  lami-
na of the mediastinum are at a greater distance  from
each other, and form a long  narrow cavity which 
Preparation of the Thorax.
47
extends down the thorax in front  of the vertebrae:
this is called the  Posterior Mediastinum.   It  con-
tains  a  considerable portion of the  aorta as it  de-
scends from its curve,  the oesophagus,  the thoracic
duct, and the vena azvgos.   The aorta is in contact
with  the left lamen, and can often  be  seen through
it when the left lung is lifted up.
  The  oesophagus,  is  in contact with the right  la-
men : in its progress downwards,  it inclines to the
left side and is advanced  before the aorta.
  The vena azygos appears posterior to the oesopha-
gus ; it proceeds  upwards until it  is as  high as the
right branch of the windpipe :  here it bends forward,
round that branch,  and opens into  the superior cava,
before that vein opens into the right auricle.
   The thoracic duct proceeds upwards from below,
lying in the space  between the aorta and the vena
 azygos, until the beginning of the curve of the aorta,
 when it inclines to the left, proceeding towards  the
place of its termination.

     The formation  of the mediastinum, and the arrangement
      of the pleura, as well as the connexion of these mem-
      branes with the parts contained  in the thorax, may be
       studied advantageously, after the subject has been pre-
       pared in the manner now to be described.
     Take away, from  each side, the five ribs which are situ-
       ated between the first and last true ribs, by separating
       their cartilages from the sternum, and their heads from
       the spine ; so that the great cavities of the thorax may
       be laid open.
     The precise course of the mediastinum is thus rendered
       obvious ; and the sternum may now be divided with a
       saw throughout its whole length in  the same direction ;
       so that the division of the bone may correspond with
       the space between the lamina of the mediastinum.
     Separate the portion of the sternum cautiously, so as to
       avoid lacerating the lamina of mediastinum ; and keep
       them separate, while the trachea is dissected from the
       neck into the cavity of the thorax;  the great transverse
       vein and the descending cava are dissected to the pe- 
        Preparation of the Thorax.

  ricardium ; and the left carotid artery, with the right
  subclavian and carotid, are dissected to the curve of
  the aorta, taking care not to destroy the lamina of the
  mediastinum.
After this preparation the  upper space between the la-
  mina of the mediastinum can be examined ; and  the
  relative situation of the trachea and the great vessels
  in it can be understood.  The  anterior  mediastinum
  can also be studied : the root of each lung, or its con-
  nexion with the mediastinum, may be seen perfectly ;
  and the precise situation of the lung, in its proper ca-
  vity, may be well conceived.
After this, while the portions  of the sternum are separa-
  ted, the pericardium may be opened, and the heart
  brought into view: the attachment of the pericardii:m,
  and to the mediastinum, and to the diaphragm, may
  be seen with  advantage in  this situation.  The por-
  tions of the sternum may  now be detached from the
  ribs, with which they remain connected ; and further-
  dissection may be performed to examine the posterior
  mediastinum and  its contents, and the parts  which
  constitute the roots of the lungs. 
CHAPTER II.
OF THE HEART AND THE PERICARDIUM, AXD THE
  GREAT VESSELS CONNECTED WITH THE HEART.

                    SECTION I.

               Of the  Pericardium.

  The  heart  is  enclosed  by a  membranous sac,
which,  upon  a superficial  view, seems only con-
nected with  its great  vessels:  but which,  in  fact,
adheres  closely to  the whole of its surface.   From
this  surface it is extended  to those vessels;  from
which it proceeds, after the manner of the reflected
membranes, and forms  an enclosure that  lies loosely
about the heart.  If it were dissected from the heart,
without laceration or wounding,  it would be an en-
tire sac.
  The pericardium, thus arranged, is placed between
the two lamina of the mediastinum, and adheres firm-
ly to  them where they are contiguous to it: it also
adheres firmly to the diaphragm below, and thus pre-
serves the heart in its proper position.
  The figure of the pericardium, when it is distend-
ed, is somewhat conical;  the base being  on  the dia-
phragm.  The cavity formed by it is larger than the
heart after death, but  it  is probable that the heart
nearly fills it during life;  for, when this organ is dis-
tended by injection,  it often occupies the whole ca-
vity of the pericardium.
  The pericardium  is composed of two lamina, the
internal of  which covers the  heart, as has been al-
ready described ; while the external  merefy extends
over the loose portion of  the other, and blends itself
  Vol. ii.                 7 
50                Of the Heart.

with the mediastinum, where that membrane invests
the great vessels.
  The  internal surface of the pericardium is very
smooth  and  polished ; and in the living subject is
constantly moistened with a fluid, which is probably
effused  from the exhalent vessels on its surface.
  The  quantity of this fluid does not commonly  ex-
ceed two drachms ;  but  in cases of  disease it  some-
times amounts to many ounces.*  It is naturally  trans-
parent, but slightly tinged with  red in children,  and
yellow in old  persons.   It is often slightly tinged
with red in persons who  have died by violence.

                    SECTION II.

                   Of the Heart.

  The great organ  of the circulation consists of mus-
cular fibres, which are so arranged that they give it
a conical form, and compose four  distinct  cavities
within it.
  Two of these cavities, which  are called Auricles,
receive the contents of the veins;  the other two com-
municate with the arteries, and are called  Ventricles.
  The  auricles form the  basis of the cone;  the ven-
tricles the body and apex.
  The  structure  of the  auricles  is much  less firm
than that of the ventricles, and  consists of  a smaller
proportion of muscular fibres.  They appear like ap-
pendages of the heart, while the ventricles compose
the body of the viscus.
  The ventricles are very thick,  and are composed
of muscular fibres closely compacted.

  * The pericardium has been so distended, by effusion in dropsy, that  it
has formel a \umour, protruding on the neck from under the sternum. This
tumour had a &trong pulsating motion.  It disappeared completely when
the other  hydrops symptoms were relieved. 
Connexions of the Heart.          51
The figure of the heart is not regularly conical:  for
a portion of it, extending from the apex to the base,
is flattened ; and in its natural position, this flat part
of the surface is downwards.
  It is placed obliquely in the body;  so that its base
presents backward and to  the right, and its apex
forward and to  the left.
  Notwithstanding this obliquity, the terms  right
and left are applied to the different sides of the heart,
and to the different auricles and ventricles ; although
they might, with equal propriety, be called anterior
and posterior.
  The  two  great veins,  called Venae Cavae, which
bring the blood from  every part of the hody, open
into the right  auricle  from above and  below;  the
right auricle opens into the right ventricle ; and from
this ventricle arises the artery denominated Pulmo-
nary, which passes to the lungs.
  The Pulmonary veins,  which bring back the blood
from the lungs, open into  the left auricle ; this auri-
cle opens into the left  ventricle ; and from this ven-
tricle proceeds the Aorta,  or great artery, which
carries  blood to every part of the body.
   The  heart is preserved in its position,  1st, by  the
venae cavse, which are connected to all  the parts to
which they are contiguous  in their course; 2d, by
the  vessels  which pass between  it and  the lungs,
which are  retained  in a  particular position  by  the
mediastinum ; 3d, by the aorta, which is attached to
the mediastinum in its course downwards, after mak-
ing its great curve;  and  4th, by the  pericardium,
which is attached  to the great vessels and to the  me-
diastinum.   'By these  different modes the basis of tte
heart is fixed, while its body and  apex are perfectly
free from attachment,  and only contiguous to tte  pe-
ricardium. 
5:>                Bight ,'htrie!;.

  The external surface of the heart, being formed by
the pericardium, is very smooth :  under this surface
a large quantity of fat is often found.
  The two auricles are contiguous to  each other at
the base,  and are separated  by a partition which is
common to both.
  The Right Auricle originates from the junction of
the two \ euse  cavae.   These veins are united at some
distance behind the right ventricle,* and are dilated
anteriorly into a sac or pouch, which  is called  the
Sinus, and extends to the  right ventricle,  to which
it is united.
  The upper part of this pouch,  or sinus, forms a
point with indented edges, which is detached from
the ventricle, and lies loose on the right side  of the
aorta.  This point has some resemblance to the ear
of a dog, from which  circumstance the whole cavity
has  been called auricle;  but by many persons the
cavitv is considered as consisting of two  portions : the
Auricle, strictly speaking; and the Sinus Venosus,
above described:  they however form but one  cavity.
  This portion of the heart, or Right  Auricle, is of
an irregular oblong figure.   In its posterior surface,
it is indented; for the direction of the two cavae,
at their junction, is not precisely the same ; but they
form an angle, which  causes  this indentation.  The
anterior portion of the auricle, or that wliich appears
like a pouch between the  ventricle and the veins, is
different  in  its  structure  from the posterior part,
which is strictly a portion of the veins.   It  consists
simply of muscular fibres,  which are arranged in fas-
 skuli that cover the whole  internal surface :  this is
 ahp; the  case  with the point, or that  part which is
 striHly called auricle.

    In this inscription the heart is supposed to be in its natural position. 
Right Ventricle.
53
  These fasciculi are denominated  Musculi Peeli-
nati, from their resemblance to the teeth of a comb.
  That part of the internal surface, which is formed
by the septum, is smooth; and the whole is covered
by a delicate membrane.
  On the surface of the septum, below the  middle,
is  an oval depression, which  has  a  thick  edge or
margin :  this is called the Fossa Ovalis.  In the foe-
tal heart,  it was the Foramen Ovale,  or  aperture
which  forms  the communication between  the  two
auricles.
  Near this fossa is a large semilunar plait, or valve,
with its  points  and  concave edge  uppermost,  and
convex edge downwards.   It was  described by  Eu-
stachius, and, therefore,  is called the  Valve of Eu-
stachius.
  Anterior to this valve,  and near the union of the
auricle  and ventricle,  is  the  orifice  of the proper
vein of  the heart,  or the  conorary vein.  This  ori-
fice is covered by another semilunar valve, which is
sometimes reticulated.
  The aperture, which forms the communication be-
tween the right auricle aud right ventricle, is about
an inch in diameter,  and  is called  ostium venosum.
From its whole margin arises a  valvular ring, or du-
plicature of the membrane lining the surface :  this
circular valve is divided into three angular  portions,
which are called Valvulac  Tricuspides.  From their
margins  proceed a great number of  fine  tendinous
threads, which  are connected to a number of distinct
portions of muscular substance,  which arise from the
ventricle.
  The right  Ventricle,  when  examined separately
from the other parts of the heart, is rather triangular
in its figure.   It is  composed  entirely of  muscular
fibres closely compacted :  and is  much thicker than
the auricle, although not so thick as the other ven- 
54
Right Ventricle.
tricle.  Its  internal surface is composed of bundles
or columns  of fleshy fibres, which are of  various
thickness and  length.  Some of these columns arise
from the ventricle, and are connected with the ten-
dinous threads, which  are attached to the  margin of
the tricuspid valves: the direction of them  is from
the apex of the heart towards the base.   Others of
the columns arise from one part of the surface of the
ventricle, and are  inserted  into  another part.   A
third species are attached to the ventricle through-
out their whole length, forming ridges or eminences
on it.  The columns of the two last described species
are very numerous.  They present an  elegant reti-
culated surface when the ventricle is  laid open, and
appear also  to occupy a considerable  portion  of  the
cavity of the heart,  which some of them run across
in every  direction  near the apex.  They  are all
covered by a membrane  continued  from the auricle
and the tricuspid valves ; but this membrane appears
more delicate  and transparent in the ventricle than
it is in the auricle.
  A portion of the internal surface of the  ventricle,
which is to the left,  is much smoother and  less fasci-
culated than the  rest: it leads to the orifice of  the
pulmonary artery, which arises from it near  the  ba-
sis of  the ventricle.  This artery is very  conspicu-
ous, externally, at the  basis of the heart.
  It is very evident, upon the first inspection of the
heart, that the valvulse tricuspides will permit  the
blood to flow from the  auricle to the ventricle ;  but
must rise and close the orifice,  and thereby prevent
its passage back again, when the ventricle  contracts.
  The use of  the  tendinous threads, which connect
the valves to  the  fleshy  columns, is also  very evi-
dent;  the valve  is supported  by this connexion,
and  prevented from yielding  to  the  pressure  and
opening a  passage  into  the  auricle.  The  blood, 
Left Auricle.
■  55
therefore, upon  the contraction of the ventricle, is
necessarily forced into  the pulmonary artery;  the
passage to which is now  perfectly free.   Into this
artery the membrane lining the ventricle  seems con-
tinued ;  but immediately within  the  orifice  of  the
artery it  is  formed into three  semicircular  folds,
each  of which adheres to the surface of the artery
by its circumference, while the edge constituting its
diameter is loose.   In the middle of this loose edge,
isasmallfirm tubercle, called CorpusculumArantii,*
which adds  to the  strength of the valve.  Each of
these valves, by its connexion with the artery, forms
a sac or pocket,  the orifice of which opens forward
towards the course  of the artery, and the bottom of
it presents towards the ventricle.  Blood will, there-
fore, pass from the ventricle in the artery, and along
it, without filling these sacs $ and on the contrary,
in this course, will compress  them  and keep them
empty.  If it moves in the artery towards the heart,
it will necessarily fill these sacs,  and press the se-
micircular portions from  the sides  of  the  artery
against each  other ; by this means a partition or sep-
tum, consisting of three portions, will be formed be-
tween the artery and the heart, which will  always
exist when the artery compresses, (or acts upon,) its
contents.  It is  demonstrable, by injecting wax into
the artery, in a retrograde direction, that these valves
do not form a flat septum, but one which is convex
towards  the heart,  and concave towards the artery;
and  that this convexity is composed of three distinct
parts, each of which is convex.  At the place where
these valves  are fixed, the artery bulges out when
distended by a retrograde  injection.  The enlarge-
ments thus produced are called the Sinuses of Val-
salva, after the anatomist who first  described them.
After Arantius, a professor at Bologna, who first described if. 
Oti
Left Ventrical.
The varfbs are called Semilunar; and, although they
are formed by a very thin membrane, they are very
strong.                                   .
   The Left Auricle is situated on the left side of the
basis of the heart.   It  originates from the junction of
the four pulmonary  veins;  two of which come from
each side of the thorax, and appear to form  a large
part of it.  It is nearly of a cubic form ; but has also
an angular portion, which constitutes the proper au-
ricle, that proceeds  from the upper and left  part of
the cavity, and is situated on the left side of the pul-
monary artery.
   This auricle is lined  by a strong  membrane,  from
which the valves between it and the ventricle ori-
ginate ;  but it has no fleshy columns or musculi pec-
tinati, except in the angular process properly called
auricle.
   These valves, and the orifice communicating with
the ventricle,  resemble  those  which have been al-
ready described between  the right auricle and ven-
tricle ; but with this  difference,  that  the valvular
ring is divided  into two portions only,  instead  of
three, which are called Vulvul&e Mitrales.  The ten-
dinous threads, which are connected to the muscular
columns, are also attached to these valves, as in the
case of the right auricle.
  These valves admit  the passage of blood from the
auricle into the ventricle, but completely prevent its
return when the ventricle contracts.  One  of them is
so situated that it  covers  the mouth  of the aorta
while the blood is flowing into the ventricle, and
leaves that orifice open when the ventricle contracts,
and the passage to the  auricle is closed.
  The Left Ventricle  is situated posteriorly, and to
the left of the Right Ventricle :  its figure is differ-
ent, for it is rather conical, and it is also longer.
  The  internal  surface  of  this ventricle  resembles 
          Muscular Fibres of the Heart.        57

that of the right ventricle ; but the columns carneae
are stronger and larger.
  On the right side of  this ventricle is the mouth of
the aorta.   The surface of the ventricle near  this
opening is smooth and polished  to  facilitate the pas-
sage of the blood.
  The mouth of the  aorta  is furnished with three
semilunar valves, after  the manner of the pulmonary
artery, but the former are stronger ; the corpuscula
arantii are better developed in them.   Indeed Mr.
Hunter does not admit of their  existence in the pul-
monary artery.   The  sinuses of Valsalva are about
the same size in both arteries.
  The  cavity  of this  ventricle  is supposed to be
smaller than  that of the right; but the amount of the
difference has not been accurately ascertained.
  This ventricle must have much more force than the
right, as its parietes  are so much thicker.   Their
thickness often exceeds half an inch.
  The difference in the strength of the two ventricles
probably corresponds with the difference between the
extent of the pulmonary artery and the aorta.
  The thickness of  the septum between the  ventri-
cles is thicker than the sides or parietes of the right
ventricle, and less thick than those of the left.
  The muscular fibres of the heart are generally less
florid than those of  the voluntary muscles ; they are
also more closely compacted together.   The  direc-
tion of many of them is oblique or spiral; but  this
general arrangement is very intricate :  it is such,
however, that the cavities of the heart are lessened,
and probably completely obliterated,  by the contrac-
tion of these fibres.*
  * Mr. Home has given a precise description of the muscular fibres of
the heart in his Croonian Lecture.  London Philosopkical Transactions for
1795. part 1. page 215.
   Vol. n.               8 • 
.38
Coronary Vessels, $c.
   The external surface of the heart  is covered by
that portion of  the pericardium which adheres to it.
Adipose matter is often deposited between this mem-
brane  and the muscular surface : being distributed
irregularly in various places.
   This membrane is continued from the surface of the
ventricles over that of the auricles.   When it is dis-
sected  off from  the  place of  their junction,  these
surfaces appear very distinct from each other.
   The proper blood vessels of the heart appear to be
arranged   in conformity to the general laws of the
circulation, and are very conspicuous on the surface.
There are two arteries which arise from the aorto im-
mediately after it leaves the heart, so that their orifices
are covered by  two of the semilunar valves.  One of
these passes from the  aorta between  the pulmonary
artery and the right auricle, and  continues in a cir-
cular course in the groove between the right auricle
and the  right ventricle, and sends off its principal
branches  to the right  side  of the heart.
   The other artery of  the heart passes between the
pulmonary artery and the left auricle.   It divides into
two branches: one, which  is anterior, passes to  a
groove on the surface,  corresponding  to the septum
between the two ventricles, and continues on it to the
apex of the heart, sending off branches in its course;
another, which is posterior and  circumflex,  passes be-
tween the left auricle and  ventricle.
   The great vein of the  heart opens into the under
side of the right auricle, as has been already mention-
ed :  the main trunk of  this vein passes for some dis-
tance between the left auricle and ventricle.*

  * It was asserted by Vieussens at an early period, in the last century,
and soon afterwards by Thebesius, a German Professor, that there were a
number of small orifices in the texture of the heart, which opened into the
different cavities on both sides of it.
  This assertion of a fact so difficult to reconcile with the general prin-
ciples of the circulation, was received with great hesitation : and although 
The Great Vessels.
59
   From the course of these  different vessels  round

the basis of the ventricles of the heart, they are ge-

nerally called  Coronary  Vessels:   the arteries are

denominated, from their  position,  Right and  Left

Coronary.

   The nerves  of the  heart come from the cardiac

plexus, which is composed of threads  derived  from

the intercostal or great sympathetic  nerves, and the

nerves of the eighth pair.


                       SECTION III.


Of the Aorta, the  Pulmonary Artery and  Veins,

   and the  Venae Cavae ;  at their commencement.


   The two great arteries, which arise from the heart,

commence abruptly, and appear to be extremely dif-

ferent in  their composition and structure  from the

heart.

   They are  composed of a substance, which has a

whitish colour  and very dense  texture, and  is very

elastic as well as firm and strong.

   When  the pericardium is removed,  these arteries

appear to proceed together from the upper part of the

basis of the heart: the pulmonary artery being placed


it was confirmed by  some very respectable anatomists of the last century,
it was denied by others.  Some of the anatomists of the present day have
denied the existence of these orifices, and some  others  have neglected
them entirely.
  The subject  has lately been brought forward in the London Philoso-
phical Transactions for 1798, Part I by a very respectable anatomist, Mr.
Abernethy, who states that he has often passed a coarse waxen injection
from the proper arteries and veins of the heart into all the cavities of that
organ, and particularly into the Left Ventricle. But it was only in sub-
jects with diseased lungs that th:s was practicable.
  The existence of this communication between  the coronary vessels and
the great cavities of the heart seems therefore to  be proved.   The easy
ilcineiMMration in such subjects is ingenious]] referred  by  Mr. Abernethy,
to the obstruction of  the circulation in the lungs : and he regards the com-
munication as a provision enabling the  coronary vessels to unload them-
selves,  when the  coronary vein cannot discharge freely into the right
aiuicltv 
60  Pulmonary Artery and Veins and Venx Cavx.

to the left of the aorta with the left auricle on the left
side of  it, and  the right auricle  on  the right side of
the  aorta.   The pulmonary artery arises  from the
most anterior, and left part of the basis of  the right
ventricle, and proceeds  obliquely backwards and up-
wards ;  inclining gradually to the left side for about
eighteen or twenty lines ; when it divides into two
branches which pass to  the two  lungs.
  The aorta arises from the left  ventricle, under the
origin of the pulmonary  artery, and immediately pro-
ceeds to the right, covered  by that  vessel, until it
mounts up between it and the right auricle:  it then
forms a great curve, or  arch, which turns backward
and to the left, to a considerable distance beyond the
pulmonary  artery.   In  this course,  it  crosses the
right branch of the pulmonary artery  ; and, turning
down in the angle between  it and  the  left branch,
takes a position on the left side of the spine.
  The course of this artery, from its commencement
at the ventricle, to the  end  of  the great curve or
arch, is extremely varied.
  The uppermost part of the curve is in the  bottom
of the chamber formed by the separation of  the  la-
mina of the mediastinum when  they join  the first
rib on each side.
  From this part of the curve three  large branches
go off, viz.  one, which soon divides into the carotid
and the subclavian arteries of the right  side;  a se-
cond, somewhat smaller, which  is  the left carotid;
and a third, which is the left  subclavian artery.
   When the heart and  its great vessels  are viewed
from behind, (after they have all been filled  with
injection ; and  the pericardium, mediastinum, and
windpipe have  been  removed,)  the aorta appears
first, descending behind the  other vessels; the pul-
monary artery then appears, dividing so as to form
an obtuse angle with its two great  branches, each of 
  Pulmonary Artery and Veins and Venae Cavae. 61

which divides again before it enters the lung to which
it is destined.
  Under the main trunk of the pulmonary artery is
the left auricle :  its posterior surface is  nearly of a
square form,  and each of the pulmonary veins  pro-
ceeds from one of  its angles.  These veins ramify in
the substance of the lungs,  at a very short distance
from the  auricle :  the two uppermost of them are si-
tuated rather anterior to the branches of  the pulmo-
nary artery.
  In this posterior view,  the pulmonary vessels  of
the right side cover a great part of the right auricle,
as it is anterior to them.   The lower portion of the
auricle, with the  termination of  the inferior cava, is
to  be seen below them.  Above  them  the  superior
cava appears ; and in that part of it which is imme-
diately above the right branch of the pulmonary ar-
tery, is the orifice of the vena azygos.
  In its natural situation in the thorax, the superior
cava is connected by cellular membrane to the right
lamen of  the mediastinum, and supported by it.  At
a small distance  below the upper edge of the ster-
num, it receives the trunk formed by the lefy subcla-
vian and  internal jugular vein, which passes oblique-
ly  across  the sternum below its inner edge, in the
upper space between the lamina of the mediastinum. 
CHAPTER III.
        OF THE TRACHEA AND THE LUNGS.

  Although the principal part of the  windpipe is
situated in the neck above the cavity of the thorax,
it is so intimately connected with the lungs, that it is
necessary  to describe them together.

                    SECTION I.

                 Of the Trachea.

  Trachea is the technical name for the windpipe,
or tube which passes from th^larynx to  the lungs.
  This tube begins at the lower edge of the cricoid
cartilage,  and passes  down  the neck in  front of the
oesophagus as low as the third dorsal vertebra, when
it divides  into two branches called Bronchia, one  of
which  goes to the right and the other to the left lung
and ramifies very minutely in them.
  There is in its structure a number of  flat cartila-
ginous  rings placed at small distances  from  each oth-
er, the edges of which are  connected by membrane
so that they  compose a tube.
  These cartilaginous rings are not complete, for they
do not  form  more than three-fourths or four-fifths  of
a circle;  but their ends  are  connected  by a mem-
brane which forms the posterior part of  the tube.
  They are  not alike in  their size or form  ;  some  of
them are rendered broader than others, by the union
of two  or  three rings with each other, as the upper-
most.   The  lowermost also  is broad,  and has a form
which is accommodated to the bifurcation  of the tube.
Their number varies, in different persons from fif-
teen to twenty. 
            Structure of the Trachea.          63

  These rings may be  considered  as forming a part
of the first proper coat of the trachea ; which is com-
posed of them, and of an elastic membrane that occu-
pies all the interstice between them ; so that the car-
tilages may be regarded as fixed in this membrane.
  A similar arrangement of  rings exists in the great
branches of the  bronchia; but after they ramify in
the lungs, the cartilages are  no longer in jjjie form of
rings : they are  irregular in their figures, and  are so
arranged in the  membrane  that they keep the tube
completely open.  These portions of cartilage do not
continue  throughout the whole extent of the ramifi-
cations ;  for they become smaller,  and finally disap-
pear, while the membranous tube continues without
them, ramifying  minutely, and probably forming the
air cells of the lungs.
  This membrane is very elastic : the lungs are very
elastic also : and it is probable that their  elasticity
is derived from this membrane.
  On the inside  of this coat of the trachea is an ar-
rangement of muscular fibres,  which  may be  called
a muscular coat.  It is  best seen  by peeling  off or
removing the internal coat to be  next described.
  On the membranous part of the trachea, where the
cartilaginous  rings are  deficient, these  muscular
fibres run evidently in a transverse direction:  in the
spaces between the cartilages their direction is lon-
gitudinal.  There is some reason  to doubt whether
these longitudinal fibres  are confined altogether to
the spaces between the  cartilaginous rings, and at-
tached only to their edges, because their is a  fleshy
substance on the internal surface of the rings, which
appears to be continued from  the spaces between
them.
  The internal coat of the trachea is a thin and  de
lioate membrane, perforated with an immense num- 
64        Black Glands of the Bronchix.

ber of small foramina, which are the orifices of mu-
cous ducts.
  On the surface of this membrane  there is  an  ap-
pearance of longitudinal fibres which  are not distri-
buted uniformly over it, but run in fasciculi in some
places, and appear to be deficient in others.  These
fasciculi are particularly conspicuous in the ramifica-
tions of the bronchia in  the lungs.
  On the posterior membranous  portion  of the  tra-
chea, where the cartilages are deficient,  a consider-
able number  of small glandular bodies are  placed,
which are supposed to communicate with  the  mucous
ducts that open on the internal  surface.   If these
bodies are removed from the external surface of this
portion,  and the  muscular fibres are also removed
from the internal, a  very thin  membrane only re-
mains, which  is very different from  that which is left
between the rings, when the fleshy substance is  re-
moved from that situation.
  The reason of the deficiency in the rings, at this
posterior part, is not very obvious.*   It continues
m the bronchia until the form of their cartilages is
changed  in the lungs:  if it were only to accommo-
date the oesophagus,  during  the passage of  food,
there would be no occasion for its extension to  the
bronchia.
  At  the bifurcation of  the  trachea,  and on  the
bronchia, are a number  of black  coloured  bodies,
which resemble  the lymphatic  glands  in form  and
texture.  They continue on the ramifications of the
bronchia some  distance  into the  substance of  the
lungs.   Their number  is often  very considerable;
and they vary in  size from three or four lines in dia-

  * Doctor Physic has advanced the opinion that it enables a person to ex-
pel the mucous of the lungs by contracting the 6ize of the trachea, and con-
sequently increasing the velocity or impetus of the air.—Ed. 
Root of the Lungs.             65
meter to eighteen or twenty.  As lymphatic vessels
have been traced to and from them during their course
to the thoracic duct, they are considered as lympha-
tic glands.

                    SECTION n.

                 Of the Lungs.

  There are two of these organs: each of which oc-
cupies one of the great cavities of  the thorax.
  When placed together, in their natural position,
they resemble the hoof of the ox, with its  back part
forward ; but they are at such a distance from each
other, and of such a figure, that they allow the medi-
astinum and heart to intervene; and they cover every
part of the heart anteriorly, except a small portion
at the apex.
  Each lung fills completely the cavity in  which it
is placed, and every part of its external  surface is in
contact with some part of the internal surface of the
cavity ; but when in a natural and healthy state, it is
not connected with any part  except the lamina of the
mediastinum.  One great branch of the  trachea and
of the pulmonary artery passes from the mediastinum
to each lung, and enters it at a place which is rather
nearer to the upper rib  than to the diaphragm, and
much nearer to the  spine than the sternum :  at this
place also the pulmonary  veins return from the lungs
to the heart.
  These vessels are enclosed in a membrane, which
is continued over them from the mediastinum, and
extended from  them  to  the lung.  Thus  covered,
they constitute what has  been called the Root of the
Lung.
  When their covering,  derived from the mediasti-
num, is removed, the situation of these vessels ap-
pears to be such that the  bronchia are  posterior,
  Vol. n.                 9 
66            Colour of the Lungs.
the branches of the pulmonary artery are.rather above
and before, and the  veins below and before them.
  Each of these vessels ramifies before it enters into
the substance  of the  lungs: the  bronchia and the
branches of the pulmonary artery send  each a large
branch downward to the inferior part of the  lungs,
from which the lower pulmonary veins pass in a di-
rection  nearly horizontal.  In general, each  of the
smaller  ramifications of the bronchia in the lungs is
attended by an artery and a vein.
  Each lung is divided,  by very deep fissures, into
portions which are called Lobes.  The right lung is
composed of three of  these lobes, and the left lung
of two.
  The lungs are covered as has been already stated,
with the reflected portion  of the pleura  continued
from the mediastinum, which is very delicate and al-
most  transparent.   They have, therefore,  a very
smooth  surface, which is kept moist by  exudation
from the arteries of the membrane.
  The Colour of the Lungs is different in different
subjects.  In children they are of a  light red colour;
in adults they are often of a light  grey ; owing to
the deposition of a  black pigment in  the substance
immediately under the membranes which form their
external surface.  Their colour is often formed by a
mixture of red and black.  In this case they are more
loaded with  blood,  and  the vessels of  the internal
membranes being distended with it, the red  colour
is derived from them.
  The black pigment sometimes  appears in round
spots of three or four lines in diameter: under the ex-
ternal membrane it  is often in much smaller portions,
and sometimes is arranged in lines in the  interstices
of the lobuli,  to be hereafter mentioned.  It is also
diffused in small quantities throughout the substance
of the lungs. 
Structure of the Lungs.          6?
  The source of this substance, and the use of it, are
unknown.
  The lun^s are of a soft spongy texture ;  and, in
animals that have breathed, they have always a con-
siderable quantity of air in them.
  They consist of cells, which communicate with the
branches of the trachea that ramify through them in
every part.  These  cells  are extremely small,  and
the membranes which compose them  are so thin and
delicate that if they  are all filled by an injection of
wax,  thrown into the trachea,  the  whole  cellular
part of the lung will appear like a mass of wax.  If
a corroded preparation be made of a lung  injected
in this maimer with force, the wax will appear like
a concretion.
  These effects of injections prove that the membranes
of which the cells are formed are very thin ; and, of
course, that their volume is very small when compar-
ed with the capacity of the cells.
  In those corroded  preparations,  in which the ra-
mifications of the bronchia are detached  from the wax
of the cells, these ramifications become extremely
small indeed.
  If the lungs of the human  subjects, or of animals
of similar construction, be  examined when they are
inflated, their  cellular structure will be very obvious,
although, their cells  are  so small  that  they cannot
commonly be distinguished by the naked eye.  Each
of the extreme ramifications of th.j bronchia  appears
to be surrounded  by a portion of this  cellular  sub-
stance, which is gradually distended when air is blown
into the ramification.
  This cellular substance is formed  into  small  por-
tions of various angular figures, which  are denomi-
nated  Lobuli: these can be separated to a consider-
able extent from each ouVr.  They are covered by
the proper coat of the lungs, which is extremely de- 
68
Structure of the Lungs.
licate, and closely connected to the general covering
derived from the pleura.  Between the lobuli, where
they are in contact with each  other, there is a por-
tion of common  cellular substance,  which is easily
distinguished through the membrane covering the
lungs.   This is very distinct from the cellular struc-
ture which communicates with  the ramifications  of
the bronchia, and contains air ;  for it  has  no com-
munication with the  air, unless  the  proper coat  of
the lungs be ruptured.   If a pipe be introduced by
a  puncture of the external coat of  the lungs, and
this interstitial cellular  membrane be inflated, it will
compress the lobuli.  This cellular membrane is al-
ways free from adipose matter:  it may be easily ex-
amined in the lungs of  the bullock.
   Upon the membranes which compose  the air cells,
the pulmonary artery and vein ramify most minutely;
and it seems to have been proved within the last thirty
years, by the united labours of chemists and physio-
logists, that the great object of respiration is to effect
a chemical process between the atmospheric air, when
taken into the air cells, and the  blood which circu-
lates in these vessels.
   In addition  to  the blood vessels which thus pass
 through the substance  of the lungs, there are several
 smaller arteries denominated Bronchial, which arise
 either from the upper  intercostal, or from the aorta
 itself:  they pass upon  the bronchia, and are distri-
 buted  to  the  substance of the  lungs.  The veins
 which  correspond  with these  arteries terminate ulti-
 mately in the vena azygos.
    The nerves of the lungs are small in  proportion to
 the bulk of these  organs.  They are derived princi-
 pally from the par vagum and the intercostal nerves.
    The elasticity of the air cells of the  lungs and of
  the ramifications of the bronchia which  lead to them,
  appears by their  rapid contraction  after distention, 
The  Thorax of the Foetus.
69
and by the force with which they expel the air which
is used to inflate them when taken out of the thorax.

            The Thorax of the Foetus.
  In the cavity between the lamina of the medias-
tinum, where they approach each other from the first
ribs, is situated a substance which is denominated
the
                 Thymus Gland.
  This substance gradually diminishes after birth, so
that in the adult it is often not to be found : and when
it exists it is changed in its texture, being much firmer,
as well as greatly diminished.
   In the foetus it is of a pale red colour; and during
infancy it has  a yellowish tinge.   It generally ex-
tends from the thyroid  gland, or a little below it, to
the pericardium.   From its superior portion two la-
teral processes are extended upwards :  below,  it is
formed into two lobes, which lie on the pericardium.
   If an incision be made into its substance, a fluid
can be pressed out, which has a whitish colour, and
coagulates upon the addition of  alcohol.
   Although it is called a gland,  no  excretory duct
has ever been found connected with it.
   The blood vessels of this body are derived from
the thyroid branches of the subclavians, from the in-
ternal mammaries,  and the vessels of the pericardium
and mediastinum.
                    The  Heart,
And the great arteries  which proceed from it, have
some very interesting peculiarities in the foetus.
   In the septum between the two auricles,  is a fora-
men of sufficient size to permit  the passage of a laFge
quill,  which inclines to the oval form, with its long-
 est diameter vertical when the body is erect.   On
 the left side of the septum, a valve,  formed by the
 lining membranes, is connected to this foramen ; and 
70
The  Thorax of  the Foetus.
 allows a free passage to a fluid moving from the right
 auricle to the left, but prevents the passage of a fluid
 from the left to the right. This structure is evidently
 calculated to allow  some of the blood  which flows
 into the right auricle from  the two venae cavae to
 pass into the left auricle of the heart instead of going
 into the right ventricle.   As the contents  of the left
 auricle pass into the left ventricle, and from thence
 into  the aorta, it is obvious that the blood, which
 passes from  the right auricle  into  the left through
 this foramen,  must  be  transmitted  from  the sys-
 tem of the  vena  cava  to  the system  of  the aorta
 without going through the lungs, as it must necessa-
 rily do in subjects who do not enjoy the foetal struc-
 ture.
       The Pulmonary Artery and the Aorta

 Have  a communication  in the foetus, which is  very
 analogous to  the communication between the auricles
 of the heart.
   From the pulmonary artery, where it divides into
 the two great branches,  another large branch conti-
 nues, in the direction of the main trunk, until it joins
 the aorta; with  which it  communicates at a small
 distance below the origin of the left subclavian artery.
 In the young subject that has never respired, it ap-
 pears as if the pulmonary artery was continued into
 the aorta, and sent off in its course, a branch on each
 side,  much  smaller  than itself, to each lung.   In
subjects that  have lived a few days, these  branches
to the  lungs  are  much larger;  and then  the main
pulmonary artery appears to have divided into three
branches: one to each lung,  and one to the aorta;
but that which continues to the  aorta is larger than
either of the others.
  In the course of time, however, this branch of the
aorta is contracted, so that no fluid  passes through it; 
General Observations.
71
and  it  has  the appearance of a ligament,  in which
state it  remains.
  The course of the blood from the right ventricle,
through the pulmonary artery, to the aorta below its
curve, is more direct than that from the left ventricle
to the same spot, through the aorta at its commence-
ment.   The column of blood in  the  aorta below its
curve is evidently propelled by the force of both ven-
tricles : and this circumstance, although it seems to
proceed merely from the state of the foetal lungs,  is
particularly calculated for the very extensive circula-
tion which the foetus carries on, by means of the  um-
bilical arteries and vein in the placenta.

             The Lungs of the Foetus

Differ greatly from those of the adult. They appear
solid, as if they were composed of the parenchymatous
substance which  constitutes  the  matter of glands,
rather than the light spongy  substance of the lungs
of adults.  They differ also in colour from  the lungs
of older subjects, being of a dull red.
  They have  greater specific gravity  than water;
but if air be once inspired, so much of it remains in
them that they ever afterwards float in that fluid.


      The nature of the process of respiration, and its ef-
        fects upon the  animal economy, particularly upon
        the action of the heart, appear to be much better un-
        derstood at this time than they were before the dis-
        covery of the composition of the atmosphere, bv Dr.
        Priestly and by Mr. Scheele. The publications upon
        this subject, which have appeared  since that period,
        viz. 1774, are therefore much more interesting to
        the student of medicine than those which preceded
        them.   Two of these publications ought to be parti-
        cularly noticed  by him:  viz, an essay, by Dr. Ed-
        ward Goodvvyn, entitled, " The Connexion of life 
72             Cases of Malformation.

         with  respiration;" and—the  '^ Physiological Re-
         searches of M. Bichat upon Life and Death.   Part
         Second.*
       The general doctrines respecting the oxygenation  or
         decarbonation of the blood, and the absolute necessi-
         ty that it should take place to a certain degree in or-
         der to preserve life, are confirmed by a number of
         cases of malformation of the heart or the great ves-
         sels, in which the structure was such that a consider-
         able portion of venous  blood passed from the right
         side of the heart to the  aorta, without going through
         the lungs. In these different cases, notwithstanding
         the structure was somewhat varied,  the symptoms
         produced were very much alike ; differing in  the re-
         spective patients in degree only, and not in kind.
            The symptoms indicating this structure are blue
         colour of the face, (such as generally accompanies
         suffocation,) extending  more or less over the whole
         body,  and particularly  apparent  under the nails of
         the "fingers and toes ; anxiety about the region of the
         heart; palpitation;  laborious respiration; sensations
         of great debility, &c: all of which are greatly aggra-
         vated by muscular exertion.  These effects have gen-
         erally appeared to  be proportioned to the quantity
         of  venous blood admitted  into the aortic system.t
            When these appearances take place immediately
         after birth, it is probable that they depend entirely
         upon malformation of the heart or great vessels; but
         when they commence at a subsequent period, they are
  * The student will derive much information respecting the publications
on this subject, prior to 1804, from Dr. Bostock's Essay on Respiration.—
Since the publication of that essay several  interesting papers on respira-
tion have appeared, viz.  Two memoirs by the  late Abbe Spalanzani;—
" An Enquiry into the Changes induced on Atmospheric Air by the Ger-
mination of Seeds," &c. by Ellis ;—two very important communications by
Messrs. Allen and Pepys in the Transactions of the Royal Society of Lon-
don for 1808 and 1809;—and " Further Enquiries into the Changes induced
on Atmospheric Air."  Also by Ellis.
  f Cases of this kind  are re s ted in several of the periodical publications
on medical  subjects.  Two cf them were described by tie late Dr. Wil-
liam Hunter in  the sixth volume of Medical Observations and Enquiries,
by a Society of Physicians in London ; one, (quoted by Dr. Goodwyn,) is
in the Observationes Anatomicse of Sandifort; and another, by Dr  J. 8.
Dorsey, has lately been published in the first number of the New England
Journal of Medicine and Surgery. 
             Cases of Malformation.            73

      commonly the effect of a diseased alteration in the
      lungs.  They sometimes occur near the termination
      of fatal cases of pneumonia or catarrh ;  but a diffe-
      rent cause, wliich has not latterly been inspected,
      appears to have produced them in the following case
      related by Dr. Marcet, in  the first volume  of the
      Edinburgh Medical and Physical Journal.
        The blue colour occurred in a young woman, twen-
      ty-one years  of age,  in whom it had never been ob-
      served before.—It came on during an affection of
      the breast, and was attended with great prostration
      of strength and difficulty of breathing ; as well as
      cough, oedema of the hands and feet, and several  ,
      other symptoms.  About seven weeks after the com-
      mencement of these  symptoms  she died ; when it
      was ascertained by  dissection,  that there was no
      unnatural communication whatever between the ca-
      vities of the heart, arid  that its valves  were all hi
      a perfect  and natural state.  The lungs were  free
      from tubercles, or any other appearance of disease.
      Their substance seemed more compact  than usual,
      especially the left lung, although it did  not sink in
      water; but  they adfiered every where to the inner
      surface of the thorax, to the diaphragm, and to the
      pleura covering the pericardium.—This case is the
      more remarkable,  because  numberless  instances
      have occurred in which very large portions  of the
      external surface of the lungs have been found upon
      dissection to  adhere to the internal surface of the
      thorax without the occurrence  of such symptoms
      during life.

    It may be inferred, from a statement published  byM.
      Dupuytren, in a late volume of  the Proceedings of
      the National  Institute of France, that the oxygena-
      tion or decarbonation of the blood is much  affected,
      in   respiration,  by  an influence exercised by  the
      nerves which are appropriated to the lungs.  From
      his account it appears, that although the complete
      division of the eighth pair of nerves produces death
      after some time ; yet in the horse whose nerves are
      thus divided, life continues,  and respiration goes
      on,  from half an hour to ten hours ; but his arterial
      blood is in a state of great disoxygenation or corbo-
      nation,during this time. T!:U facti* more rc.yjrka-
Vol, ii.                  10 
74    Effects of Venous  Biood on  the Heart.

         ble, because venous blood,  contained in a bladder
         expose! to the open air, will become oxygenated or
         decarbonated.
           It is also asserted in another Memoir, read to the
         National Institute by Dr. J. M. Provencal, that ani-
         mals in whom the eighth pair  of nerves has bee A
         divided, do not consume so much oxygen, or produce
         so much carbonic acid, by a considerable degree, as
         they did before  the division of these nerves ; and,
         that their temperature is considerably reduced.*

       The fact, that venous blood occasions death, when it is
         admitted into the left ventricle of the heart, and the
         aorta, is truly important.  Dr. Goodwin explained it
         by suggesting that this blood was not sufficiently sti-
         mulating to produce the necessary excitement of tho
         heart; but on this occasion one of his friends propo-
         sed to him the following question:  Why does venous
         blood affect the left side of the heart in this injurious
         manner, w,hcn it appears to exert no noxious effects
         whatever on  the right-, side of that organ? His reply
         may be seen in a note at the 82d page of his Essay,
         in the first edition.  Bichat has offered  a solution
         which completely resolves this difficulty, viz.  " Tho
         effect of venous blood upon the heart is produced by
         the presence of this blood in the proper, or coronary
         arteries of that organ, and not  in its great cavities."
         For the animation of the heart, like that of the other
         parts of the body, depends upon the state of the blood
         in the arteries which penetrate its texture.t  And
         while the heart  acts, the blood of the coronary arte-
         ries will be the  same with that of the left ventricle.
         SS<.-e Bichat's  Researches, P. II. art. 6. § 2.
       The French Auatomists appear to entertain some pecu-
         liar opinions respecting  the course of the blood in
         the foetus, which have a particular relation to the sub-
         ject last mentioned.   Winslow, who paid great at-
         tention to the v:ilve of Eustachius in the right auricle
         of the heart,  was of < ^iiion, that  this valve was cat-

   * These Memoirs are republished in the Eclectic Repertory  of Phila-
 delphia for April ami October, 1811.
   f It is prolr.J,!,. that the contents of the great  cavities of the heart have
 no more * fleet upon its animation than the conttii-s of the Stomach and
 bowels have ut-uu ;!.•_ animation of those 0!g;u.'j, 
          Sentiments of Sahatb-r,  fyc.          75

    culated for some important purpose in the foetal eco-
    nomy.*   Although his hypothesis respecti--ig its pai-
    ticular use has not been retained by his counti-viiUMi,
    many of them have adopted his- general sentiment;
    and among others Sabatier. That l"arued anatomist
    believed that this valve, in  the foetal state, serves
    to direct the blood of the inferior cava, after its ar-
    rival in the right auricle, through the foramen ovale
    into the left auricle $  while the blood of the  upper
    cava  passes directly into (he rigid ventricle.   His
    opinion seems to be supported to a certain degree.
       1.  By the direction m which the two columns of
    blood enter the amicie from the two venae cavae.
       2.  By the position of the K i-tachiun valve.
       3.  By the foramen iovale, when  its valve is com-
      filete; as the pawaa-e thn-.'Jigh it, from the right to the
      eft,is at that time oh!! ]uc, and from Helow upwards.
       The theory of Sabatier appears to he this: 1!.. um-
    bilical vein brings from the placenta blood which has
     a quality essential to the animation of the foetus. If
    there wore no particular provision to the conuary, a
    large portion of this blood,  after  passing from the
    umbilical uln  by the  inferior  cava into  the right
    auricle of the heart, w.mld proceed by the right ven-
    tricle, though  the pulmonary aretry and arterial  ca-
    nal, into the aorta, below  the origins of the carotid
    and subclavian arteries: and consequently none of
    it would pass to the head and upper extremities, but
    a considerable part would return again by the umbi-
    lical  arteries  t-  the placenta, without circulating
    through the body : while  on the  other hand,  the
    blood which pi *s*d by the carotid  and subclavian
    arteries to the head and upper extremities, return-
    ing from *hem to the  heart by the superior cava,
    might pa*;s fitm the right  auricle to the left auricle
    and vom'rir.lfi and the aorta, and so to the head* and
    tipper extremities a^ain,  without  passing  through
    the pla er.t i.  But by means of this valve, the blood
    of the lower cava, and of course  of  tin.- umbilical
    vein, is directed  to the left auricle  and ventricle
    and the aorta, by which a considerable portion of
    it will necessarily pass to  the head  and upper ex-
    tremities : while the blood which returns from these

* See Vun.A;.i-: of the Academy of Sciences for  1717 and 1725. 
76
Sentiments of Sabatier, $c»
         parts by the superior cava, must consequently pass
         from the right  auricle into the right ventricle and
         pulmonarv artery ; from whence a large portion of it
         will proce'ed through the arterial canal into the aorta
         beyond the carotids and subclavians, and of this por-
         tion a considerable part will go to the placenta by the
         umbilical arteries. Sabatier compares the course of
         the blood in the foetus to the course of a fluid in a tube
         which has the form of the numeral character 8.*—If
         this doctrine be true, the progress of the blood in  the
         foetus and placenta is very analogous to that of the
         double circulation  of the adult; the character 8  an-
         swering equally well in the description of either sub-
         ject.
           According to Sal»atier,  the blood of the placenta
         takes this  peculiar course through the heart, in order
         that some of it may be carried to the head and upper
         extremities.   But  an additional reason may be sug-
         gested, which appears  to be of great importance;
         viz. the supplying of the coronary or proper vessels
         of the heart  with some of the same blood.
           The heart of the adult, as has been before stated,
         cannot act without its proper or coronary arteries  are
         supplied with arterial blood. The heart of the foetus
         performs a more extensive circulation than that (if the
         adult, and therefore  is probably in greater need of
         such blood.  But unless the blood of the placenta pas-
         ses through the foramen ovale into the left auricle and
         ventricle, and so to the aorta, it cannot enter the coro-
         nary arteries which originate  at the commencement
         of the aorta; for  the  blood which flows from  the
         right side  of the heart through the arterial canal,
         passes into the aorta at so great a distance from  the
         orifices  of the  coronary arteries, that it  certainly
         canhot enter them.
   *•     The whole of this doctrine seems to be supported by
         a fact, very familiar  to accoucheurs, viz. the occur-
         rence of death in the fcetus whenever the circulation
         through the umbilical cord is suspended during fifteen
         or twenty  minutes: for as the placenta imparts to the
         foetal blood a quality essential to life,  some arrange-
         ment seems necessary to provide for the equal distri-
         bution of the blood which comes from this organ, and

  * See Sabatier's Paper on this subject in the Memoirs of the Aca.temy
of Stiences, for 1774. 
  Unusual Cases of Malformation.       77

especially for carrying the requisite proportion of it
to the substance of  the heart.            •
Life has existed for some time with a structure very
  different indeed from that which is natural.  In the
  series of elegant engravings relating to morbid ana-
  tomy, published by Dr. Baillie, is  the  representa-
  tion of a heart, in which the  venae cavae  opened
  into the right auricle, and the pulmonary veins into
  the left auricle, in the usual manner ; but the aorta
  arose entirely from the right ventricle, and the pul-
  monary artery as completely from the left.  The
  canal is arteriosus, however, passed from the pulmo-
  nary artery to the aorta, and the foramen ovale ex-
  isted.   In this case it is evident  that the pulmona-
  ry artery must have carried back to the iungs the
  arterial blood which came from them by the pulmo-
  nary Aeins, with a small  quantity of venous blood
  that passed into the left auricle  through the foramen
  ovale; and that  the aorta must have returned to the
  body, the venous blood which just before had been
  brought, from it by the venae cavse, with a small ad-
  dition of arterial blood  that  passed  through the
  ductus arteriosus.   Vet, with this structure, the
  child lived two  months after its birth.
     A case, which had  a strong resemblance to the
  foregoing, occurred lately in Philadelphia, and wa9
  examined  by the author  of this work.  The venae
  cavae terminated regularly in the right auricle, and
  the pulmonary veins in the same  regular manner in
  the left; but the pulmonary artery arose from the
  left ventricle, and the aorta from the right.   There
  ' was no communication betioeen these vessels by a ca-
  nalis arfcrio.vai; but a large opening existed in the
  septum between the auricles.
     It is very evident,  that in this case also the pul-
  monary artery must have returned to the lungs the
  arterial blood as it came from them, and the aorta
  must have  carried  back  to the general system the
  venous blood brought to the heart by the cavae j ex-
  cepting  only those  portions  of the  arterial  and
  venous blood which must have flowed reciprocally
  from one auricle into/the  other,  and thus changed
  their respective situations. 
7is               foramen Ovale.

           The subject was about two years and a half old.
        . The heart was nearly double the natural size, and
         the foramen, or opening in the septum beb>e< i. the
         auricles, was eight or nine lines in diameter.   Tho
         pulmonary  artery was larger in proportion than lie
         aorta or the heart.
           With this organization the child lived to the age
         above specified.  His countenance  was generally
         rather livid ;  and this colour was always much in-
         creased by the least irregularity of respiration. His
         nails were  always livid.  He sometimes appeared
         placid, but  more frequently in distress.  He  never
         walked,  and seldom,  if ever,  stood on his  feet.
         When  sitting on the floor, he would sometimes pu<h
         himself about the room; but this musciHar exertion
         always greatly affected his respiration.  He attain-
         ed the  size  common to children of his age, and h;»d
         generally a great appetite.  For some weeks before
         death hislegs and feet were swelled.
           It is probable that the protraction of life depend-
         ed upon the mixture of the blood in the two  .uiri«
         cles ; and that they really were to be consider cd as
         one cavity,  in this case.


       There seems reason to believe, that in  adults of the
         common structure, there is no passage of blood from
         one auricle  to  the  oiher, when  the  foramen ovale
         has remained  open; because in several persons in
         whom it was found by dissection to have remained
         open, there were no appearances during life  that in-
         dicated the presence of disoxygenated blood in the
         aortic system.  It is probable, that the small size
         of the foramen ovale,  the valvular structure which
         generally exisls there, and* the complete occupation
         of the left auricle by the blood flowing from the pul-
         monary veins, prevent the passage of blood from the
         right auricle to the left, in such persons ; whereas,
         in the  case in question, the opening  between the
         auricles was  very large indeed,  and  there was  no
         appearance of a valve about it.
  Although it be admitted, that in  adults with the
foramen ovale pervious, there is no transmission of 
On the Source of the motion of the Heart.  79
        blood from the right to the left auricle; there is
        every reason to believe that  this transmission goes
        oh  steadily  in the  foetus.    To  the arguments,
        derived from the structure  and the nature of the
        case, it may be added, that the pulmonary veins, in
        the foetal  state, carry to the left auricle a quantity
        of blood,  not sufficient to fill it; while the venae
        cava* carry to  the right auricle not only the whole
        blood of the body,  but of the umbilical cord  and
        placenta : some of" which must flow into the unfilled
        left auric de, when the  right  auricle becomes fully
        distended.


      The question how far  the functions of the heart and
        lun^s are dependent upon the brain is very impor-
        tant, and has  often been agitated with great zeal.
        In favour  of the opinion  that the  motions  of the
        heart are independent of the brain, may be stated
        the numerous cases in which the brain has been de-
        ficient in children,  who have notwithstanding lived
        the full period of utero-gestation, and even a short
        time after birth, and have arrived at their full size,
        with every appearance of perfect vigour and action
        in the heart.   In support of  the  doctrine, that the
        action of the heart  is immediately dependent upon
        the brain, it may be observed, that no organ of the
        body appears to be  so much influenced by passions
        and other mental  affections as  the heart.   These
        contradictory facts  have occasioned this question to
        be considered as undecided, if not incapable of so-
        lution ; although Cruikshank and Bichat*have stated
        circumstances very favourable to  the opinion that
        the motions of  the  heart are independent  of the
        brain.


           This question seems now to be settled by the ex-
        periments of Dr. Legallois, a physician of Paris,

  * See Cruikshank's Evperimcnts on  the Nerves and Spinal Marrow of
living animals ; London Philosophical Transactions for 1795.  The eighth
experiment has a particular relation to lias subject.
  Bichat's researches, part 2, article 9.
  The Abbe Fontana haa consi^'iud this subject in hi* Treatise on tLo
Venom of the Vip«:r, vol. ii. page 191 E-vrPsh translation; antl also ;:i
6-:i " of his oth-r works. 
80  Humboldt and others on Legallois9 Paper.

         which prove, that in animals who have suffered de-
         capitation, the action of the heart does not cease as
         an immediate consequence of the  removal of the
         head ; but its cessation is an indirect effect, induced
         by the suspension of respiration.   That respiration
         is immediately affected by decapitation, and depends
         upon the influence of the brain transmitted through
         the eighth pair of nerves.   That the action of the
         heart will continue a long time after decapitation,
         if inflation of the lungs, or artificial respiration, be
         performed ; but,  on the contrary, if the spinal mar-
         row be destroyed, the action of the heart ceases ir-
         recoverably.
           The inference  from these experiments seems very
         conclusive,  that  the  Spinal Marrow, and not the
         brain, is the  source of the motions of the heart.
           It appears also by some of the experiments^ that
         the power of motion in the trunk of the body is de-
         rive,, from the spinal marrow; and that when this or-
         gan is partially destroyed, the parts which receive
         nerves from the destroyed portion soon cease to live.
         By particular management of the  spinal  marrow,
         one  part of  the  body can be  preserved  alive for
         some time after the other parts are dead.
      These experiments of Dr. Legallois  commenced  in
         1806 or  1807, and were communicated  to the Im-
         perial Institute of France in 1811.  The committee
         of  that  body to whom  they  were  referred, viz.
         Messrs. Humboldt.  Halle and  Percy, reported that
         the experiments had been  repeated  before them, a£
         three different meetings of several hours each; and
         that to allow themselves  sufficient  time  for reflec-
         tion,  they suffered  an interval of a week to  take
         place between the  meetings.   The committee be-
         lieve these experiments to have proved,
           1st. That  the principle upon which all the move-
         ments of inspiration depend, has its seat about that
         part of the medulla oblongata from which the nerves
         of the eighth pair arise.
           2d.  That the principle which animates each part of
         the trunk of  the body is seated in that portion of the
         spinal marrow from which the nerves of the part arise.
           3.  That the source of the  life and strength of
         the  heart is also in the spinal marrow; not in any
         distinct portion, but in the whole of it. 
Brodie on the Source of the Motion of the Heart. 81

        4th. That the great sympathetic nerve is to be consi-
      dered as originating in the spinal marrow, and that the
      particular character of this  nerve is to place each of
      the parts to which it is distributed under the immedi-
      ate influence of the whole nervous power.
    The interesting memoir of Dr. Legallois is confirmed to
      a certain degree by a communication of B. C. Brodie
      to the Royal Society of London in 1810, in which are
      detailed many  very interesting experiments which in-
      duced the author to conclude,—
        That the influence of the brain is not directly ne-
      cessary to  the action  of the heart; and
        That when the brain is injured or removed, the action
      of the heart ceases, only because respiration is under its
      influence;  and if  under these  circumstances respira-
      tion is artificially produced, the circulation will still
      continue.
    These various experiments apply particularly to the cases
      in which the brain is deficient.  The effects of mental
      agitations on the heart are likewise reconcilable to the
      theory which arises out of them.   But they throw no
      light on the question why the motions of the heart are
      so perfectly free from the influence of the will:  and
      although they seem to prove incontestibly that the mo-
      tion of the heart is independent of the brain, it ought
      to be remembered that in  certain diseased  states of
      the brain, where that organ appears to  be compressed,
      the action  of the heart is often  very irregular, and its
      contractions less frequent than usual.
Vol. ii.
U 
SYSTEM OP ANATOMY.

               PART VIII.
               OF THE ABDOMEN.

  The lowermost of the two  great cavities of the
trunk of the body is called  Abdomen.  The pelvis
may be considered as a chamber of this cavity, al-
though its structure is very different.

                 CHAPTER I.

A GENERAL VIEW OF TFIE ABDOMEN AND PELVIS AND
  THEIR CONTENTS, WITH AN ACCOUNT  OF THE PE-
  RITONEUM.
                   SECTION I.

                Of the Abdomen.

  This great cavity occupies more than half of the
space enclosed by the ribs, and all the interior of the
trunk of the body below the thorax.
  It is formed by the  diaphragm,  supported by the
lower ribs; by a portion of  the spine  ; by the  vari-
ous muscles^which occur between  the lower margin
of the thorax and the  upper margin of  the ossa in-
nominata; and by the ossa  innominata,  which con-
tribute, for the purpose,  the  costae of the ossa ilia,
as well as the pelvis. 
Construction of the Abdomen.        83
   The general figure  of this cavity partakes of the
figure of the lower  part of the trunk of the body ;
with these exceptions, that the diaphragm makes it
arched or vaulted above, that the  spine  and  psose
muscles, &c. are rather prominent on the  posterior
surface, and that the lower part corresponds with the
costae of the ossa ilia and with the pelvis.
   To acquire a precise idea of this cavity, it  is ne-
cessary  first to  study the bones  concerned  in  its
structure, in their natural  situation in the skeleton;
and then  the  muscles, which form so  large a part
of it.
   The arrangement of the tendons of some of these
muscles, with a view to complete the cavity, is par-
ticularly interesting ;  as that of the external oblique
where it forms the crural arch.*   The  ligaments of
the pelvis and  the levatores ani muscles, as they also
contribute to the formation of the cavity, and  have
an influence upon its  figure, should likewise be at-
tended to.
   In the walls  of the cavity, thus constructed, there
are many foramina by which the viscera and  other
contained parts communicate  externally  ; but few of
them  pass directly into the cavity ;  for like the tho-
rax, there are  no vacuities in it exterior to the con-
tained organs.
   Three of these foramina  are  in the  diaphragm.
One for the transmission of the aorta, another for the
vena cava, and a third for the oesophagus.   Below,
there is an aperture at each of the crural arches, for
the transmission of the great femoral vessels ; in each
of the ligamentous membranes, which close the fora-
men thyroideum, for the obturator vessels and nerve;
and at the sacro sciatic notches, for nerves and blood
vessels.
  * See the account of this tendon, vol. i. in the description ©f th« " Ob»
'iijuus Decendens Externus." 
84        Construction of the Abdomen.

   There are also two apertures at the bottom of the
pelvis, for the orifice of the rectum and of the ure-
thra.  In  the tendons of the  external oblique mus-
cles are two orifices, covered by the integuments, for
the spermatic cords ; and, in the  foetal state, one for
the umbilical  cord.
   The  apertures  in  the tendons,  and under  their
edges, for the transmission of the  spermatic cords,
and  the blood vessels, &c. are  not to be considered
as simple perforations made abruptly; but  the edges
of  these foramina are formed  by  tendinous mem-
branes turned inwards  and continued so as to  com-
pose a cylindrical  tube, which  becomes gradually so
thin that it cannot be readily distinguished from the
cellular membrane with which it is connected.*  The
blood vessels,  &c.  pass  along this tube before they go
through  the apertures.
   It is evident from  the construction of this cavity
that it is essentially different from  the thorax.  It
has no power  of spontaneous dilatation whatever : it
yields passively to the distention of  the stomach and
intestines,  during  deglutition, and when air is extri-
cated from the aliment, &c. ; but it is particularly
calculated for  compressing its  contents by the  con-
traction of the muscles  which compose it.   The di-
minution of its capacity, which is thus effected, not
only takes  place to a great degree,  but occasionally
with great force.   The diaphragm  and the abdomi-
nal muscles may be considered in  some measure as
antagonists of  each other.  When  the diaphragm
descends, if the abdominal muscles are passive,  they
are distended  by the contents of the abdomen, which
are forcibly pressed from above ; but if the abdomi-
nal muscles act at  the same  time, an effort to dimi-

  * The student of anatomy, when engaged with this subject, will be
gratified by the examination  of Mr. Astley Cooper's plates relating to
hernias. 
Contents of the Abdomen.         85
nish the cavity in every direction takes place, and the
contained parts are compressed with more or less force
according to the exertion made.   This will be very
evident upon examining the situation of the diaphragm
and of  the abdominal muscles.  When their force is
considered it will also be very obvious that the vari-
ous outlets of the cavity are constructed most advan-
tageously ; otherwise hernia or protrusion of its con-
tents would be a daily occurrence.
  The abdomen contains, 1st. The Stomach and the
whole Intestinal  Tube, consisting of the small and
the great intestines.
  2d.  The  Assisting  Chylopoietic  Viscera,—the
Liver, the Pancreas and the Spleen.
  3d.  The  Urinary Organs,—the  Kidneys, the
Ureters, and the Bladder.  To which should be add-
ed the Glandulae Renales.
  4.  The Organs of Generation in part: those of
the female sex  being  almost  wholly included in the
pelvis; and those of the male being situated partly
within and partly without it.
  5th.  The Peritoneum and its various processes.
The  Mesentery, Omentum, &c.
  6th. A portion  of the Aorta,  and  almost the
ichole of the Inferior Cava,  and  their great ramifi-
cations: with such of their branches  as  are  appro-
priated to the Viscera of the Abdomen and Pelvis.
  7th.  Those portions  of the Par Vagum and In-
tercostal A'erres which are appropriated to the cavi-
ty ; and portions of some of  the  nerves destined  to
the lower extremities.
  8th.  The lower part of the Thoracic Duct,  or
the Great Trunk of the Absorbent System, with the
large branches that compose it, and  the  glands con-
nected with them ;  and also  those absorbent vessels
called  Lac teals, and their glands.
   As the cavity of the abdomen has no natural divi- 
86          Begions of the Abdomen.

sions, anatomists have divided it  by imaginary lines
into various regions, with a view to precision in their
accounts of the situation of the different contained
parts.   Thus,
  They have, very generally, agreed to  apply two
transverse lines to form three great  divisions;  viz.
the Upper, Middle, and Lower : and they have also
agreed that each of these divisions shall be subdivid-
ed into  three regions.
  The three regions of the uppermost division are
denned with some precision.  Those on  each side,
which are called the Bight and Left Hypochondriac
regions, occupy the spaces immediately within the
lower  ribs and  their cartilages; while the  middle
space, included within the margins  of these cartila-
ges,  and a  line drawn  from the lower edge of the
thorax on one side to that on the other, is  denomi-
nated the Epigastric region.
  The boundaries of the regions below are less pre-
cisely defined.
  Many anatomists have  fixed  the two  transverse
lines above mentioned at an arbitray distance above
and below the umbilicus : some choosing for this pur-
pose two inches, and others a hand's  breadth.   As
these distances will occupy different proportions  of
the cavity in persons of different stature, other ana-
tomists, with a view to avoid this inconvenience, have
proposed  to counect  these  lines with certain fixed
points of the  skeleton.
   It is  of importance that  the  boundaries  of these
regions should be fixed, and therefore the  proposi-
tion of Sabatier may be adopted ; viz. To draw the
upper transverse line from the most inferior  part  of
the lower margin of the thorax, on one side, to the
corresponding part on the opposite side; and the
lower transverse line from the uppermost part of the 
Begions of the Abdomen.           87
spine of  one ilium to the same  part of the  other.
These lines will mark the three great divisions.   If
then two parallel lines are drawn directly upwards,
one from each of the  superior  anterior spinous pro-
cesses of the ilium until it touches the lower margin
of the thorax, they will divide  each of the two lower
divisions of  the abdomen  into  three regions.  The
centre of the middle  division  is  the umbilical, and
on each side  of it is the right and left lumbar region.
The middle  of the lower division is the hypogastric ;
and on each side of it the right and left iliac region.
  It is true, that the three middle regions of the  ab-
domen will be made very small  by the vicinity of  the
transverse lines to each other; but the  advantages
derived from a  principle which is similar in  its  ap-
plication to all subjects fully eumpensates for this in-
convenience.
  There are therefore nine of these regions: viz.
The Epigastric and the two Hypochondriac: the Um-
bilical, and the two Lumbar:  the Hypogastric, and
the two  Iliac regions.*   And  it  should be added,
that the space immediately around the end of the ster-
num is sometimes  called the  Scrobiculus Cordis;
and the space immediately within  the os pubis,  the
Regio Pubis.
  These different regions are  generally  occupied in
the  following manner.   The   liver fills  nearly  the
whole of the right hypochondriac region, and  ex-
tends through the upper part of the epigastric  region
into  the left hypochondriac.  The stomach  occupies
the principal part  of the epigastric  region,  and  a
considerable portion of the left hypochondriac.  The
spleen is also situated in the  left hypochondriac re-

  * It is to be observed that the lateral regions of the middle and lower di-
visions of the abdomen are named differently by different writers. 
88     Situation of the Viscera, $c. in the

gion.   That portion of  the intestinal tube, which is
composed of  small  intestines, is  generally found in
the umbilical, the hypogastric, and the iliac regions;
and when the bladder is empty, in the pelvis.   But
the duodenum, or first of the small intestines, which
proceeds immediately from the stomach, is situated
in the epigastric and umbilical  regions.  The great
intestine commences in or near the right iliac region,
and ascends through the right lumbar to the right
hypochondriac  region.   It then crosses the abdomen,
passing through the lower part of the epigastric, or
upper part of the umbilical to the left lumbar region ;
from this it continues into the left iliac region,  and
curves in such a manner that it finally arrives at the
middle of the upper part of  the os sacrum, when it
descends into the pelvis, and, partaking of the cur-
vature of the last mentioned  bone, continues to the
termination of the os coccygis.
  In the back part  of the epigastric region, and very
low down in it, is situated the pancreas.   The kid-
neys lie in the  most posterior parts of the lumbar re-
gions, and  from each of them is continued  a tube or
duct, called Ureter, that passes into the pelvis to con-
vey the urine to the bladder.  This  viscus, in males,
is in contact with the last portion of  the great intes-
tine called the  Rectum, and with it  occupies almost
all the cavity of the pelvis; while  in females, the
uterus and its appendages are situated between this
intestine and the bladder.
  In the posterior part of the abdomen, in  contact
with the spine  is the aorta.   This great blood ves-
sel passes from  the  thorax between the crura of the
diaphragm, and continues down the spine  until it
approaches towards the pelvis,  when it divides  into
two great branches  called the Iliac Arteries.   Each
of these  great  branches divides  again, on  the  side 
              Cavity of the Abdomen.           89

of the pelvis,  into  two; viz. the External  Biac,
which passes under the crural arch to the thigh, and
the Internal Iliac, or Hypogastric, which  descends
into the cavity of the pelvis.
   Soon after the arrival of the aorta in  the  abdomen
it gives off two large branches.   The first, which is
called the Cceliac, is distributed to the liver, the sto-
mach, and the spleen:  the  second, called the  Supe-
rior Mesenteric, is spent upon the intestines. Lower
down, in  the abdomen, it  also  sends off a small
branch for  the intestines,  called Inferior Mesen-
teric.  Besides these vessels for the chylopoietic vis-
cera, the aorta sends off a large branch,  called Emul-
gent, to each kidney.
   The inferior  or ascending vena cava is situated
on the right of the aorta,  in front of the spine.   It is
formed below by the union of the iliac  veins, and in
its progress upwards it receives the emulgent  veins,
which correspond to the arteries of the kidneys ; but
it receives in its course no  veins  which correspond
directly with  the coeliac  and  mesenteric  arteries.
The smaller veins, that answer to the branches  of
these arteries, unite  and form  one large vein, which
goes to the liver, and is called, (from the part of that
viscus at which it enters,) Vena Portarum.   From
the liver three large veins pass  into the vena  cava,
and deposit there  the  blood of the vena portarum,
after it has furnished materials  for the secretion  of
bile.   The vena cava, in  its passage upwards, is in
close contact with  the posterior  thick  edge of the
liver : it often passes along a deep groove in this
edge, and  sometimes it  is  completely surrounded by
the liver in its course.   The veins of the liver  enter
the vena cava  at  this place, and of course  they are
not to be seen without  dissection.  Immediately af-
ter leaving the liver  the vena cava parses through an
   Vol. ii.               12 
90
The Peritoneum.
aperture in the  tendinous  centre of the diaphragm
to unite itself to the right auricle of the heart.
                    SECTION II.
               Of the Peritoneum.
  The  abdomen, thus constructed  and  occupied, is
lined by a thin firm  membrane called Peritoneum,
which  is extremely smooth on its  internal surface,
and is immediately connected with  the  cellular sub-
stance exterior to it.  This membrane adheres close-
ly to the anterior, lateral, and superior portions of the
surface of the abdomen; and is extended  from the
posterior surface  so  as  to  cover, more or less com-
pletely,  the viscera of the cavity.  Those viscera
which are in close contact with the  posterior surface
of the abdomen, as some portions of the large intes-
tine, are covered only on their anterior surfaces, and
are fixed in their  precise situation  by the peritone-
um ; which extends  from them  to the  contiguous
surface  of the cavity, and adheres where it is in con-
tact, so as to produce this effect.
   Other viscera,  which are not in close contact, but
moveable to a distance from the posterior  surface of
the abdomen, are covered  by  this membrane, which
is extended to them from the surface;  and this ex-
tended  portion  forms an important  part  of the con-
nexion between the viscus and the cavity in which it
lies.   This connecting part  is  called  Mesentery,
when it thus passes to the small intestines; Mesoco-
lon, when  it goes to the colon, one  of the larger in-
testines ;* and Ligoment, when it  passes  to some of
the other viscera.
   The  peritoneum  is  a complete  but  empty  sac,
which is fixed in the abdomen anterior to the viscera.
The anterior portion of this sac forms  the lining to
the anterior and  lateral parts of the surface of the 
                 The Peritoneum.               91

 abdomen:  the posterior portion covers the viscera,
 and forms the  mesentery, mesocolon,  and ligaments
 above described.
   It necessarily follows  that the mesentery and the
 other similar processes are mere plaits or folds of the
 sac,  which  iuvests the viscera ; and that they  must
 consist of  two lamina;  and as the  blood vessels,
 nerves, and absorbents, are all posterior to the peri-
 toneum, they  naturally pass between these lamina of
 the  mesentery.
   Some 01 the viscera are much more  completely in-
 vested with the peritoneum than others.   The sto-
 mach,  liver,  and  spleen, are  almost completely
 surrounded  by it; and it is said to  form a coat for
 eacli of these  viscera.  That  portion  of the smaller
 intestinal tube, which is  called jejunum and ileum,
 and the transverse portion of the large  intestine,  call-
 ed the arch of the colon, are invested by it in the
 same way.   But a considerable portion of  the duo-
 denum and the  pancreas  is behind it.   The lateral
 portions of trie  colon  are  in  close contact with the
 posterior surface of the abdomen, and  the peritone-
 um only covets that  portion of their surfaces which
 looks anteriorly towards the cavity  of  the abdomen,
 and  is not in coutact with its posterior  surface.
   The  urinary organs are not  much connected with
 the peritoneum.  The kidneys appear exterior to it,
 and  behind it: the bladder of urine is below it, and
 has but a partial covering from it, on its upper por-
 tion.
   The peritoneum, which covers the stomach, is ex-
 tended from the great curvature of that organ so as
 to form a large membrane, which descends  like an
 apron before the intestines.  This process of perito-
 neum is composed of  two lamina, so thin and deli-
cate  as to resemble cellular  membrane, which, after
 extending downwards to the lower part of the abdo- 
9:3
The Peritoneum.
men, are turned backwards  and upwards, and pro-
ceed in that direction until they arrive at the colon,
which  they enclose, and then continue to the back of
the abdomen, forming the mesocolon.  The  part of
this process which is  between  the  stomach and the
colon,  is called Epiploon or Omentum.
  This extension of a membrane,  from  the surface
of a cavity, which it lines  to the external surface of
a viscus in that cavity, is called, by some anatomists,
" reflection ;" and the technical term reflected mem-
brane  is therefore applied to a membrane distributed
like the peritoneum.
   It must be evident that this distribution of the pe-
ritoneum is very complex, and  that it is not easy to
form an accurate conception of it  from description,
but it  can be  readily understood by demonstration ;
therefore no further account of its arrangement will
now be attempted,  but each of its processes will be
considered with the organs to which they are parti-
cularly subservient.
   That portion of the  peritoneum which lines the
abdomen and  covers the viscera, is thin and delicate,
but very firm.  It yields to distension, as in preg-
nancy, ascites,  &c. and again recovers its dimen-
sions.   It was formerly thought to be composed of two
lamina, but this cannot be  proved.  The  internal
surface of this membrane is very smooth, and highly
 polished;  and from it exudes a liquor which is well
 calculated  for lubrication,  and barely  sufficient to
 keep  the surface moist during  health ; but sometimes
 it  is very abundant, and occasions  the aforesaid dis-
 ease—ascites.    This fluid  appears to  exude from
 the surface of the  peritoneum when it is compressed
 in a living animal, or in one  recently dead.   It  is
  probably effused from the extremities of arteries, for
  an effusion takes  place  when water is injected into
  these vessels. 
The  Peritoneum.
93
  The peritoneum abounds with absorbent vessels,
and therefore possesses the power of absorption  to a
great degree.  This power may be inferred, not only
from the spontaneous removal of the fluid of ascites,
but if milk and water be introduced into the abdomen
of a living animal, through a puncture,  it  will  also
disappear.
  The blood vessels of  the  peritoneum  are derived
from those which supply the   neighbouring  parts.
Nerves have not yet been traced into it, and  it has
little or no sensibility.
  This membrane supports the viscera of the abdo-
men in their proper situations: and also forms a  sur-
face for them, and  for  the cavities which  contains
them, so smooth  and  lubricated, that no injury can
arise from their  friction.
   The cellular substance, by which  the  peritoneum
is connected  to the contiguous parts, is very  different
in different places.   It  is very  short indeed between
this membrane and  the stomach  and intestines, and
also between it and the  tendinous centre of the  dia-
phragm.  Between the  peritoneum and  the muscles
generally, it  is  much  longer.   When it covers the
kidneys  and  the psoas  muscles  it is very lax  and
yielding.   About the  kidneys a large  quantity of
adeps  very commonly collects  in  it. On the psoas
muscle it yields with  but little  resistance to  the  pas-
sage of pus, or any other effused fluid, as in the  case
of the psoas abscess. 
CHAPTER II.
OF  THE CESOPHAGUS, THE STOMACH, AND THE IN-
                    TESTINES.

                    SECTION I.

               Of the (Esophagus.

  The (Esophagus is a muscular tube which passes
from the pharynx to the stomach, and is so intimate-
ly connected with the stomach, that it will be advan-
tageous to the student to attend to its structure im-
mediately before he  engages in  the  examination of
that important organ.
  The pharynx has been  lately described* as com-
posed of a varied stratum of muscular fibres, lined by
a membrane which is continued from the internal sur-
face of the nose and mouth.   From the pharynx the
oesophagus passes  downwards between  the  trachea
and the  vertebrae.   After the bifurcation of the tra-
chea,  it  proceeds in contact with the spine, between
the  lamina of the  mediastinum,  to the  diaphragm,
which it passes through, and  then  terminates  in the
stomach.
  The oesophagus  is  a flexible  tube, which,  when
distended,  is  nearly cylindrical.    It  consists  of a
muscular coat externally, and an internal tunic evi-
dently continued from that of the pharynx.  These
coats  are  connected by a cellular substance  called
the  Nervous Coat,  which is remarkably loose, and
allows them to  move considerably  upon  each other.
The  muscular  coat which  is very  distinguishable
from that of the pharynx, consists of two substantial
strata of fibres; the exterior of which is  nearly lon-
* See page 37. 
The (Esophagus.
95
gitudinal in its direction, and the interior circular or
transverse.
  The internal coat of the oesophagus,  resembling
that of the fauces, is soft and spongy.  It is covered
with a very delicate cuticle, which Haller  supposed
to be to tender  to confine the matter of variolous
pustules, as he had never found these extending into
the oesophagus.   It is  very vascular, and  abounds
with the orifices  of mucous follicles, from which  is
constantly poured out the mucous that is  spread over
this surface.  When the oesophagus is not distended,
many longitudinal plaits are found in  this membrane
by the contraction of the circular or transverse fibres
exterior to it.  These plaits are calculated to admit
readily of the distention which is requisite in deglu-
tition.  This  tunic is continued from the lining mem-
brane of the  pharynx above, and terminates below in
the villous coat of the stomach ; from which, howev-
er, it is very different.
   The  blood vessels of the esophagus  come  from
those which  are  in the vacinity.   The  nerves are
derived from the eighth pair.   The  lymphatic ves-
sels are very abundant.
   In the neck, the oesophagus inclines rather to the
left of the middle line.  As  it proceeds  down the
back between the lamina of the mediastinum, it pre-
serves the same course to the fourth dorsal vertebra,
when  it assumes the middle  portion and  proceeds
downwards,  with the aorta to its left, and the  peri-
card'nm brfore it.  About the ninth  dorsal vertebra
it inclines again rather to the left,  and somewhat for-
ward, to arrive  at the aperture in  the diaphragm
through which it passes.
   Throughout this course it is connected by cellular
membrane  to the contiguous parts ; and  this investi-
ture of cellular  membrane  has  been called its Ex-
ternal Coat. 
96            Form of the Stomach.
  While the cesophagus is in the posterior mediasti-
num, it is in contact with several  small absorbent
glands,  especially when it  first assumes a situation
to the right of the aorta.  These glands were  for-
merly believed  to be  particularly connected  with
this  tube, but they are now considered as belonging
to the absorbent system.  They are sometimes great-
ly enlarged.

                     SECTION II.

                 Of the  Stomach.

  This  most important  organ  which  occasionally
exerts a powerful influence upon every part of the
body, appears very simple in its structure.
  It is a large sac, which  is so thin when much in-
flated that  at first view it seems membranous, but
upon examination is found to be composed of several
lamina or coats,  each  of a  different structure.  It  is
of considerable length, but incurvated.   It is much
larger at one extremity than the other,  and changes
so gradually in  this  respect, that it  would  appear
conical if it were straight.   It is not, however, strictly
conical,  unless  it is greatly distended ; for when
moderately distended,  a transverse  section is rather
oval than circular.  It is therefore considered as hav-
ing  two  broad  sides or  surfaces,  and  two edges,
which are the curvatures.  It has been compared by
the  anatomists of different nations  to the wind sac
of the musical instrument called the bagpipe.*  The
orifice  in which the cesophagus  terminates is  at a
small  distance  from its  largest  extremity, and  is
called Cardia.   The  orifice  which   communicates

  * The student ought not to attempt to acquire an idea of the form of
the stomach without demonstration, for a view of one moment will be
more  serviceable than a long description. 
Position of the Stomach.          97
 with the intestines is at  the termination of its small
 incurvated extremity, and is called the Pylorus.
   The two ends of the stomach being thus very dif-
 ferent in size, are denominated the great and  small
 extremities.  The two curved portions of the surface
 are also called the great and small curvatures.  The
 two flat portions of  the  surface,  or the broadsides,
 are called the anterior and posterior surfaces.
   The situation of the stomach  in the abdomen  is
 nearly transverse: it lies principally in the left hy-
 pochondriac and epigastric regions, immediately be-
 low the liver.  The great extremity of the stomach
 is in the left  hypochondriac region, and  the lesser
 extremity in  the  epigastric  region,  under  the left
 lobe of  the liver.  The upper orifice,  or  Cardia,  is
 nearly opposite to the body of the last dorsal ver-
 tebra ; and owing to the curved form of the stomach,
 the other orifice, or Pylorus, is situated  at a  small
 distance to the right of that bone,  and  rather lower
 and more forward than the cardia : both orifices be-
 ing in  the epigastric region.  The position of the
 stomach is oblique in two respects; it inclines in  a
 small degree  from above  downwards, from  the left
 to the right; and it also inclines downwards  and
 forwards,  from behind.   Its two orifices are situated
 obliquely  with respect to each other; for,  if the sto-
 mach, when placed with its small curvature upwards,
 were divided into two equal parts by a vertical plane
 passing lengthways through it, they would be found
on different sides of  the plane.
   As the cesophagus terminates in the stomach  im-
 mediately after it has passed through an aperture of
 the diaphragm, it is  evident  that the stomach  must
 be somewhat  fixed at that place ; hut it is more move-
 able at its other orifice ; for the extremity of the duo-
denum, into which it is continued, is moveable.
   Vol. ii.              13 
98       External Coat of the Stomach.

  The stomach is connected  to  the concave surface
of the liver by the  reflexion or continuation of the
peritoneum which forms the  lesser omentum.   This
membrane, after extending over each surface of the
stomach continues from its great curve in the  form
of the large omentum, and connects it to different
parts, especially to  the colon.   There are likewise
folds of the peritoneum, as  it passes  from the dia-
phragm and from the spleen to  the  stomach, which
appear like ligaments.
  Notwithstanding  these  various  connexions, the
stomach undergoes considerable  changes in its posi-
tion.   When it is nearly  empty, and  the  intestines
are in the  same situation, its broad surfaces are pre-
sented forwards and backwards ; but when it is dis-
tended, these  surfaces are  presented  obliquely up-
wards and  downwards, and the  great  curvature for-
wards.  When its anterior surface is  presented up-
wards, its orifices are considerably influenced in their
direction, and the cesophagus forms an angle with the
plane of the stomach.
   The stomach is composed of four dissimilar lamina,
which may be demonstrated by a simple process  of
dissection.
   There  is first a coat or external  covering  conti-
nued from the peritoneum : within this, and connect-
ed to it by delicate cellular substance, is  a coat  or
stratum of  muscular fibres: contiguous to these fibres,
internally, is a layer of dense cellular substance, call-
ed a nervous coat; and last is the internal coat of the
stomach, called villous or fungous, from the structure
of its surface.
   The external  or  first  coat of the stomach,  as has
been already stated, is continued from the concave
 surface of  the liver to the  lesser curve of the sto-
 mach in two delicate lamina, which  separate when
 they approach the stomach, and pass  down, one  on 
  Muscular and A^ervous Coats of the Stomach. 99

each side of it, adhering firmly to it in their course:
at the opposite curve of the stomach they again unite
to form  the great omentum.   The stomach is there-
fore closely invested by the peritoneum on every part
of its surface except two strips, one at the lesser and
the other at the greater curvature.   These strips or
uncovered places are formed by the separation of the
lamina above mentioned, which includes a triangular
space bounded by the stomach and these two lamina.
In these triangular spaces, at each  curvature of the
stomach, are  situated the blood vessels which  run
along the stomach in  those directions, and  also the
glands which belong to the absorbent vessels of this
viscus.  The  peculiar arrangement of the lamina at
this place is particularly calculated to permit the dila-
tation of the stomach.  When it is dilated the lamina
are in close contact  with its surface,  and the blood
vessels being in  the angle formed by the adhesion of
the two lamina to each other, are so likewise : when
it contracts, the blood vessels appear to recede from
it, and the lamina are then applied to each other.
  Where the peritoneum thus forms a coat to the sto-
mach, it is stronger and  thicker  than  it is between
the liver and stomach. In a recent subject it is very
smooth and moist, but so thin that the muscular fibres,
blood vessels,  &c. appear through it.  If it is care-
fully dissected from the  muscular coat, it  appears
somewhat flocculent on that surface which adhered
to the muscular fibres.  It seems to be most abundant-
ly furnished with serous vessels ;  but it has been as-
serted by Mascagni and Soemmering,  that a large
proportion  of its texture consists of absorbent ves-
sels.  The cellular substance which  connects this to
the muscular coat appears no way different from or-
dinary celhiiar membrane.
  The Muscular Coat of the stomach has been  de-
scribed  verv differently  by  respectable anatomists; 
100       Internal Coat of the Stomach.

some considering it as forming three strata of fibres,
and others but two.  If the sto.nach and a portion of
the oesophagus attached to it be moderately distended
with air,  and  the external  coat carefully dissected
away, many longitudinal fibres will appear on every
part of it,  that evidently proceed from the cesophagus:
these fibres are  particulary numerous  and strong on
the lesser  curvature of the stomach.—Beside the lon-
gitudinal  fibres there are many that have a circular
direction, and  these are  particularly numerous to-
wards the small extremity ; but it has been doubted
whether there are any fibres in the muscular coat of
the stomach that go directly round it. The wholesur-
face of the stomach, when the peritoneal coat is re-
moved, appears at first view to be  uniformly covered
by muscular fibres; but  upon close examination,
there are  interstices perceived, which are occupied
with firm cellular membrane.
   In contact with the  internal surface of the mus-
cular coat is the  cellular stratum, which has been
called the Nervous Coat of the stomach.   It is dense
and firm,  of  a whitish colour, resembling condensed
cellular membrane.  It was considered as dift'erent
from ordinary cellular membrane; but if air  be in-
sinuated into its  texture,  by blowing between the
muscular  and villous coats, while it connects them to
each other, it exhibits the proper  appearance of cel-
lular substance.  It however adds greatly to the ge-
neral strength  of the stomach, and the vessels which
terminate in the villous coat ramify in it.
   The internal coat of the stomach in the dead sub-
ject is commonly of a whitish colour, with a tinge of
red.   It  is named villous, from  its supposed  resem-
blance to the  surface  of velvet.   It  has also  been
called fungous, because the processes analogous to
the villi are  extremely short, and its  surface  has  a 
Gastric LiquOr.
101
granulated appearance;  differing in these  respects
from the internal surface of the intestines. It is con-
tinued from the lining membrane of the oesophagus,
but is very different in  its structure.   Many very
small  vessels seem  to enter  into  its texture, which
are derived from branches that ramify in the nervous
coat.  It  is supposed by several anatomists of the
highest authority,  to have a  cuticle or epithelium ;
and it is said that such a  membrane has been sepa-
rated  by disease.  It ought however,  to be remem-
bered, that the structure of the villous coat of the
stomach and intestines, is essentially  different from
the structure of the cuticle.
  The internal coat of the stomach is generally found
covered, or spread over, with mucous, which can be
readily scraped off.   This mucous is certainly effus-
ed upon it by secreting organs, and it has been sup-
posed that there were small  grandular bodies exte-
rior to the villous coat, which furnished this  secre-
tion ;  but the existence of such bodies is very doubt-
ful, as many skilful anatomists  have  not met with
any appearance that could  be taken for glands, ex-
cept in a very few instances, which would not be the
case if those appearances had been natural.   Pores,
perhaps the orifices of mucous follicles, and also  of
exhalent vessels, are very numerous, but no proper
glandular masses are attached to them.  Glands,  as
have  been already said, are  found in the triangular
spaces between the lamina of the  peritoneum  at the
great and small curvatures of the stomach, but these
evidently belong to  the absorbent system.  Besides
the mucous above mentioned, a large quantity of a
different liquor, the proper Gastric Juice, or fluid of
the stomach, is effused from its surface.  It  has been
supposed  that this  fluid is furnished  by the small
glandular bodies believed to exist hetween the coats 
102
The Pylorus.
 of this origin; but, admitting the existence of these
 glands, they are not sufficiently numerous to produce
 so much of it as is found, and it is therefore probable
 that this fluid is discharged from  the  orifices of ex-
 halent vessels  in the internal surface.
   Much  information  respecting  the  gastric  liquor
 has been  obtained within  a  few years  past  by the
 researches  of  physiologists,  and they  are  generally
 agreed that it  is the  principal agent in the effects
 produced  by the stomach  upon  alimentary substan-
 ces.*
   As  the  muscular coat of the stomach frequently
 varies its dimensions, the villous and  nervous coats,
 which have no such power of contraction, cannot ex-
 actly fit it.   They therefore generally appear larger,
 and of course are thrown into folds or rugae.   These
 folds are commonly in a longitudinal direction ;  but
 at the orifices  of the stomach they are arranged in a
 radiated manner, and  sometimes  they are  observed
 in a  transverse direction.   They depend upon  the
 contraction of the muscular fibres, and  disappear en-
 tirely when the stomach is laid open and spread  out.
   At the lower orifice is  a circular fold,  which is
 permanent, and constitutes the valve denominated


  * On this subject the student may consult with advantage.
  M. Reaumur. In the Memoirs of the Academy of Sciences for 1752.
  John Hunter. London Philosophical Transactions  for 1772 ; and also
his observations on the Animal Economy, 1786.
  Dr. Edward Stevens.  Inaugural Thesis de Alimentorum Concoctione
Edinburgh, 1777.
  The Abbe Spalanzani.  Dissertations relative to Natural  History &c.
The first volume of the English translation contains the author's disserta-
tions on digestion, and also the first paper of Mr. Hunter, and the Thesis
of Dr. Stevens, as well as an account of the experiments of Mr. Gosse of
Geneva.
  In addition to these, there are several interesting essays in the French
German, and Italian languages, a compilation of which is to be found in
Johnson's " History of the progress and present state of Animal Chemistry "
See Vol. I. page 180. 
     Lymphatics and Nerves of the Stomach.  103

Pylorous.  It appears like a circular septum with a
large foramen in its centre, or like a flat ring.   The
villous and nervous coats of the stomach contribute
to this, merely by forming the circular fold or ruga;
and within this fold is a ring of muscular fibres, evi-
dently connected with the circular fibres of the mus-
cular coat of  the stomach,  the diameter of which at
this place is not  larger than that of an intestine :  the
fibres of this ring seem  a part of the muscular coat
projecting into the cavity of the stomach and duode-
num.   If a portion of the lesser extremity of the sto-
mach  and the adjoining  part of the duodenum be de-
tached, and laid open by a longitudinal incision, and
then spread out upon a board, the internal coat can be
very easily dissected from the muscular, and the py-
lorous will then  appear like a ridge or narrow bundle
of muscular fibres, which runs across  the  extended
muscular membrane.  It is evident that when  the
parts are replaced so as to  form a cylinder, this nar-
row fasciculus will  form a ring in it   Thus arrang-
ed, the circular  fibres can readily close the lower ori-
fice of the stomach.
  The pylorus separates the stomach from the intes-
tine duodenum ; and this separation is marked  exte-
riorly by a small circular  depression, which corres-
ponds exactly with the  situation of the pylorus.
   The arteries  of the stomach are derived from  the
 Coeliac, the  first branch which the aorta sends off to
the viscera of the abdomen.  This great artery, im-
mediately after  it  leaves the aorta,  is divided into
three branches, which are distributed to the stomach,
the liver, and the spleen, and are called the Superior
 Coronary or Gastric, the  Hepatic, and the Splenic.
Beside the first  mentioned branch, which is distri-
 buted principally to the neighbourhood of the cardia
 and to the lesser curvature, the stomach receives a
 considerable branch from  the  hepatic, which passes 
.104
The Intestines in general.
 along the right portion of its  great  curvature,, and
 has been called the right gastro-epiploic, and another
 from the spleen, which passes along  the left portion
 of the great curvature, and has been called  the left
 gastro-epiploic.  In addition to these branches, the
 splenic artery, before it enters the spleen, sends off
 several small arteries  to  the great extremity of the
 stomach, which are called vasa brevia.
  These vasa brevia generally arise from the main
 trunk of the splenic artery, but  sometimes from its
 branches.
  The  veins which receive the blood from these ar-
 teries have similar names, and pursue corresponding
 courses backwards; but they  terminate in the vena
 portarum.
  The absorbent vessels of the stomach are very nu-
 merous and  large :  they pass to the glands which are
 on the two curvatures, and from thence to the thoracic
 duct.  It is an important fact relative to the history
 of digestion, that there are good reasons for doubting
 whether chyle commonly passes through them, not-
 withstanding their  number and size.*
  The nerves of the stomach are derived principally
from the two great branches of the par vagum, which
accompany the oesophagus and  are mostly spent upon
 this organ.   It  also receives branches from  several
 plexus, which are derived from the  splanchnic por-
tions of the intercostal nerves.

                    SECTION III.

                Of the Intestines.

  The intestines form a  continued  canal from the
 pylorus to the  anus, which is generally  six times
  * Sabatier, however, in one subject observed white lines on the stomacB,
 which he suspected to be lacteals. See bis account of the absorbents of
 the stomach. 
          Villous Coat of the Intestines.       105

the length of the subject to which they belong.   Al-
though the different parts of this tube  appear some-
what different from each other, they agree in their
general structure.  The coats or lamina of which they
are composed, are much like those of the stomach,
but the  peritoneum which forms their external coat
does not approach them in the  same manner;  nor is
it continued in the form of omentum from the whole
tube, there being only a certain portion of intestine,
viz. the colon, from which such a  process of perito-
neum is continued.
  The  Muscular Coat, like  that of the stomach,
consists  of two strata,  the exterior of which is com-
posed of  longitudinal fibres,  which  adhere to the
external coat, and do not appear very strong.  The
other stratum, consisting of circular or  transverse
fibres, is stronger, as the fibres are more numerous.
It is observable that they adhere to the longitudinal
fibres:  and they seldom if ever form complete  cir-
cles.
  The  cellular  substance immediately  within  the
muscular fibres resembles  the  nervous coat of the
stomach in its firmness and density.  It is likewise
so arranged as to form many circular ridges on its in-
ternal surface, which support to a certain degree the
permanent circular plaits of the internal coat, called
valvulze conniventes.
  The inner surface  of  the internal  coat has been
commonly compared to that of velvet, and the coat
is therefore  called villous ; but there is certainly a
considerable  difference between these surfaces;  for
if a portion of the small intestine be inverted, and
then suspended in perfectly transparent water, in a
clear glass, and examined with a strong light,  it will
appear  like  the  external  surface of the  skin of a
peach, on which the down or hair-like processes are
not so  close  as those  on  velvet.   On this surface,
  Vol.  ii.               14 
106
Lieberkuhn on the  Villous Coat.
between the villi, there are many orifices of mucous
follicles and of  exhaling vessels.*  Exterior to the
villous  coat, many very small  glandular bodies are
sometimes found, which are called after their descri-
bes Glandulae Brunneri and Peyeri.
  The  internal coat of the  upper portion of the in-
testinal tube is arranged so as to form a great  num-
ber of transverse or  circular folds  or plaits,  called
Valvulse Conniventes, which do not generally extend
round the intestine, but are segments of  circles; they
are  so  near each other  that their internal  edges,
which are very moveable, may be laid upon the folds
next to them, like tiles  or  shingles.   It  is evident
that this arrangement of the internal  coat must add
greatly to its length.   This coat is  extremely vascu-
lar,  so that in the dead subject it can be  uniformly
coloured by a successful injection. The  minute struc-
ture of it has been the subject of very diligent inquiry.
There can be no doubt  but  that an  immense number
of exhaling and of absorbent vessels  open upon it;
but  there are many different opinions respecting the
termination of one set of vessels and the commence-
ment of the other.
   A very interesting account of the  Villous Coat was
published in 1744,  by  Lieberkuhn,  who was con-
sidered by  his contemporaries as a most expert prac-
tical anatomist, and was  also very skilful in  micro-
scopical examinations, for which  he was particularly
calculated, as his natural powers of vision were un-
commonly  strong.    In his  essay  he  refers to his
preparations, which were at Berlin, and which ap-
pear to have excited great  surprise in  the minds of

  * It appears clearly, from the account of Lieberkuhn, that the ori-
 fices or terminations of the arteries on the intestines, are distinct from
 the follicles ; for he forced injection from the arteries into the cavity of
 the intestines, and found the follicles still  filled with mucous.  He then
 urged the injection further, and filled the follicles, or forced the mucous
 out of them. 
          Hewson and others on the Villi.      107

 the members of the Academy of Sciences of Prussia,
 at a time when one of the first anatomists of Europe,
 the celebrated Meckel, was of their number.
   According to this account, the internal surface of
 the small intestines abounds with villi, and with the
 orifices of follicles.  These villi are  about the fifth
 part of a line in breadth.  In each of them is a cavity
 filled with a soft  spungy  substance, which  has  one
 or more orifices communicating with the intestines,
 and from which  also proceeds a lacteal  vessel.   On
 the membrane which forms this cavity, blood vessels
 are most minutely ramified.  This cavity he calls an
 ampullula, and  supposes it to constitute the principal
 part of the villous.   By injecting the arteries of the
 intestine,  he was  able to pass a fluid through  the
 ampullula into  the  cavity of the  gut; he  kept a
 stream of air in  this way passing through  the am-
 pullula until it was nearly dry  and stiff, and then
 laid it open with  a fine instrument.   From  the  ap-
 pearances which then presented, he inferred that the
cavity of the ampullula was occupied with a spongy
 or cellular substance.   Around each villus he found
 a number of mucous follicles,  which often were filled
 with  a tenacious mucous: and distinct  from these
 must  be the  exhalent orifices, which discharged a
 fluid injected by the arteries without passing through
 the mucous follicles.
   Lieberkuhn died early, and left but one essay  on
 this subject, which was originally published in Hol-
land,  in 1744, but has been republished by the Aca-
demy  of Berlin, in their  Memoirs ; and also by Mr.
John Sheldon, of London.
  This account of Lieberkuhn appears  to  have
 heen  admitted  by Haller; but it  has been rigidly
scrutinized by  some  of  the  anatomists  of London,
 who were particularly interested with the subject;
 as they had  paid great  attention  to the absorbent 
108       Fyfe and others on the  Villi.

system, and were very successful in the  investiga-
tion of it.                          .
  The late Mr. Hewson, whose opinion is entitled to
the greatest respect, rejected the idea of the ampul-
lula, and believed that the villi are composed of net-
works of lacteals, as well as  arteries and veins; al-
though he added that " this is the only circumstance
concerning these parts in which he  should differ from
this very acute observer."*
  Mr. Sheldon agrees with Lieberkuhn :  but Mr.
Cruikshank asserts, that, " in some  hundred villi,
he  has  seen  the  lacteals  originate  by  radiated
branches, whose orifices were distinct, on  the surface
of the villus."   The villus being transparent, when
the intestine was immersed in water, these branches,
filled with chyle could be seen passing into the lac-
teal.   Mr.  Cruikshank therefore supposes that Lie-
berkuhn was mistaken,  and that the spongy cavity,
or ampullula, was the common cellular  membrane,
connecting together all  the arteries, veins, nerves,
and lacteals.
   It  seems probable, from Mr. Cruikshank's  state-
ment, that  Dr. William  Hunter  held  the same
opinion with himself.  And there  is also  reason to
believe that Monro the second, who studied  anato-
my at Berlin, held a different opinion  from Lieber-
kuhn.
   Mr. Fyfe, who has been much  employed  in the
investigation of  the absorbent system,  and  must  be
perfectly acquainted with the preparations of Monro,
asserts that each lacteal  takes  its  rise upon  one of
the villi by numerous short radiated branches, and
each branch is furnished with an orifice for imbibing
chyle.
   Several of the late French writers adopt the opi-

       * See Hewson's Experimental Inquiries, vc!. 2t pagt 171. 
Division of the Intestines.
109
nion of Lieberkuhn ;  but his countryman Soemmer-
ing gives a different account of the subject.  He says,
that, besides the blood vessels, each villus consists of
a fine  net-work of absorbent vessels, whose orifices
may be distinctly recognised ; and thjft from  six to
ten of these orifices are sometimes discovered.
   Mascagni, who has published the  most extensive
work upon the absorbent system that has yet appear-
ed, supposes Lieberkuhn to have been mistaken, and
confirms the  description of Hewson:  but he  also
agrees with Hewson in his opinion of the general ac-
curacy of Lieberkuhn.
   Notwithstanding their  differences respecting the
origin of the lacteals, all these observers have agreed,
that the orifices which communicate with  the lacteals
are on the villi;  and that these villi contain  also
very fine ramifications of blood vessels.   They have
also agreed, that the  surface of the intestines in the
intervals of the villi seems occupied with the orifices
of ducts or of exhalent vessels.*

            Division of the Intestines.

   Although there  is a considerable degree of  uni-
 formity in the structure of the  intestinal canal, dif-
 ferent parts of  it are very distinguishable from each
 other by their exterior  appearance, by their size,
 their  investments, and their position.
   The first division is into two great portions, which
 are very different from each other in their diameter
 and length, as  well as their situation :  the first  por-
 tion being much  smaller in diameter, and  uear four
 times the length of the  other.

   * On  this subject the student will consult with advantage,  Hewson's
 Experimental Inquiries, vol.  2; Sheldon's  History of the Absorbent
 System, part 1st; Cruikshank on the Anatomy of the Absorbing Ves-
 sels ; and the  Historia Vasorum Lymphaticorum Corporis Humani,  of
 Mascagni. 
110
Division of the Intestines.
   These portions are therefore known by the names
 of Great and Small Intestines, and the line of sepa-
 ration between them is very strongly marked; for they
 do not gradually change into each other, but the  al-
 teration in siz*e and  in  exterior appearance  is very
 abrupt, and their communication is not perfectly  di-
 rect. A considerable portion of the Great Intestine
 is fixed  immoveably in the abdomen, while a large
 part of the Small Intestine is very moveable.
   Each of these great portions of the intestinal tube
 is subdivided into three parts.   Thus, in the  Small
 Intestine, there is a piece at the commencement call-
 ed Duodenum, a great part of which has no coat from
 the peritoneum, and is immoveably fixed in one situa-
 tion ; while all the  remainder of  the small intestine
 has a uniform covering from the peritoneum, and is
 very moveable.   This last piece,  notwithstanding
 its exterior uniformity, is considered as forming two
 parts.   The  uppermost two-fifths  form one  part,
 which is called  Jejunum; and  the  remainder is
 called Ileum.   The Great  Intestine commences in
 the lower part of the right side of the abdomen, and
 after proceeding  up that side crosses  over  to the
 left, along which it  descends to the lower part again,
 when by a peculiar  flexure  it proceeds to the cen-
 tre of the posterior  margin of the pelvis,  from which
it passes down to the anus.   A short portion of this
intestine, which is above its junction with the ileum,
is called Csecum ; the part which proceeds from this,
round the abdomen,  is called Colon ; and the por-
tion  which is in the pelvis is called Rectum.

             Of the Small Intestines.

  Previous to the description of the small intestines,
it  is necessary  to observe,  that the Mesocolon,  or
proc ss of the peritoneum connected to the  trans-
verse portion of the colon, forms a kind of moveable 
      Commencement of the Small Intestines.   Ill

and incomplete septum, which divides the abdomen
into an upper and lower apartment.  Above this sep-
tum are the stomach, with the commencemenf of the
duodenum, the liver, and the spleen;  below it, that
portion of the small intestine which is called jejunum
and ileum, makes  its appearance.  The portion  of
the intestine which  passes from  the stomach to the
jejunum, and is called Duodenum, is  so  much  in-
volved by the mesocolon, that the greatest part of it
cannot be seen without dissecting the mesocolon from
its connexion with the back of the abdomen.—For
the duodenum proceeds backwards from the pylorus,
and passing down behind  the peritoneum, enters a
vacant space  between the two lamina of the mesoco-
lon ;  it proceeds for some distance in this space, and
then  emerges on the lower side of the  mesocolon.
Here the duodenum terminates, and the small  intes-
tine then is invested by the peritoneum in such mari-
ner as to form the mesentery, which continues with it
throughout its whole course to  the great intestine.
This  portion  of the intestine, although very uniform
in its exterior appearance, as has been  observed  be-
fore,  is divided into Jejunum and Ileum : the jeju-
num being the upper portion, which  begins  at  the
mesocolon ; and the ileum the lower portion, which
opens into the great intestine.
                Of the Duodenum.

   The length of this intestine is  equal to the  breadth
of twelve fingers, and hence its name.   It is very
different from the rest of the small intestine,  not only
as respects its position and investment by the perito-
neum, but on account of its connexion with the liver
and pancreas,  by means  of their excretory ducts,
which open into it.  From this connexion with these
glands,  probably, all the peculiarities of its  position
are to be deduced. 
112     .   Situation of the Duodenum.

  When the stomach is in its  natural situation,  the
pylorus is at  some distance from the back of  the
abdomen.   The  duodenum  proceeds  backwards
from  this point,  and passes  near the neck of  the
gall-bladder,  being here  connected  with the small
omentum ; it then curves downwards,  and descends
before the right kidney, sometimes as  low as  the
lower part of it; then it curves again,  and passes
over to the left:  after it has arrived at the left side
of the spine, at the second or third lumbar vertebra,
it projects forwards and  downwards to form the je-
junum.   The only portion of  this intestine which is
moveable, is  that which  is  in sight as it proceeds
immediately from  the pylorus, being about an inch
and a half or  two inches in length.   The remain-
der is connected to the back of the abdomen, and lies
between the  two  lamina  of the  mesocolon.  In its
progress its passes before the aorta and the vena cava,
but the principal branch of the vena portarum is be-
fore it.
  The duodenum is larger in diameter than any other
part of  the small  intestines,  and  has a stronger mus-
cular coat.  Its general situation admits of great dilata-
tion, and it has been called a second stomach. Its in-
ternal coat is  strictly villous, in the anatomical sense
of the word;  and its folds, the valvulae conniventes,
begin at a small distance from  the pylorus.  The  ori-
fices of  many mucous ducts are to be seen on its sur-
face.   It is supposed that some of these are the ter-
minations of ducts from the glands of Brunner, which
sometimes appear in the villous coat,  or very close to
it exteriorly;  being small flat  bodies, with a depres-
sion in the centre, and a foramen in  the  depression.
They are sometimes very numerous at the upper ex-
tremity of this intestine, and  diminish gradually to-
wards the other extremity.
  The biliary and pancreatic  ducts open posteriorly 
Jejunum and Ileum.
113
into the duodenum, rather above the  middle of it.
The orifice of these ducts is generally surrounded by
a small tubercle, which is oblong, somewhat rounded
at one extremity, and pointed at the other.   Some-
times this orifice is in a plait, like one of the valvulae
conniventes.  Most commonly the two ducts unite
before they perforate the coat, so as to  form but one
orifice; and sometimes they open separately, but al-
ways very near to each other.
  Absorbent  vessels, which contain chyle, are found
on the duodenum.

             The Jejunum and Ileum

Are situated  in the abdomen very differently from
the duodenum.   When the cavity is opened, and the
omentum raised, they are in full view ;  and every
portion of them, except the two extremities and the
parts near them, can readily be moved.   This free-
dom of motion is owing to the manner in which they
are invested by the peritoneum ; or in  the technical
language of anatomy, to the length of  their  mesen-
tery.  They agree in their structure with the general
description of the small intestines, but their muscular
coat is rather  weaker than that of the duodenum. The
valvulae conniventes are very numerous and large in
the upper part of the tube, or the jejunum ; and gra-
dually  diminish in  number, until  they  finally disap-
pear, in the lower part of the ileum.   The  villous
coat is in perfection in  the jejunum,  the villi being
more conspicuous there than in any other part of the
intestinal tube.  There are frequently found, exterior
to this  coat, but intimately connected with it, many
small glandular bodies of a roundish  form, which are
often clustered  together at that part  of the intestine
which  corresponds with the interstice of  the  lamina
of the  mesentery.   They are called  Peyer's glands,
   Vol. ii.              15 
114  Distinction between Jejunum and Ileum

after the anatomists who first described them; and are
supposed, like the glands of Brunner, to secrete mu-
cus.   If a portion of  the jejunum be inverted, and
moderately distended  with air, these bodies appear
very distinctly in it, dispersed at small distances from
each other.   In the ileum they appear in small clus-
ters, which often have the appearance of  disease.
   No natural line of separation for distinguishing the
jejunum and ileum from  each other, is to be found;
but these names are still  retained ; and therefore a
rule laid down  by Winslow is  generally adopted,
viz. to  name the first two-fifths of the tube jejunum,
and the remainder ileum.  There are, however, some
important differences between these portions of the
intestine.
   In the jejunum, the valvulae conniventes are so nu-
merous, that they lie in contact with each other,  as
shingles on  the roof  of a house; in  the  ileum they
gradually diminish in number, and finally disappear.
In the jejunum the villi  are much stronger than they
are in the ileum.
   It is very difficult to acquire a precise  idea of the
arrangement of this part of the intestinal  tube, while
it is in the abdomen, especially if it be much distend-
 ed ; but if it be separated at each extremity from the
 intestine with  which  it is connected, and the mesen-
tery cut  off from the back of the abdomen,  and the
 whole  then spread  out  upon a flat surface,  it will
 appear, as has been already said, that  the intestine
 is arranged so as  to form  a  semicircle or large
 curve; the concavity of which  is opposite to the
 back of the abdomen, while  the convexity presents
 forward.   It  will also appear,  when thus  placed
 upon  a  table, that  the  intestine,  while connected
 with the mesentery,  is laid  into many  folds.   It has
 been supposed, that the middle portion of the mesen-
 tery, and the intestine connected with it, is generally 
          Construction of the Mesentery.       115

in the umbilical region ; and the two portions on the
sides of it are in the iliac regions ; but their situation
in the abdomen varies considerably at different times.
When the viscera of the  pelvis are empty, a large
portion  of the small  intestine  is in  the pelvis; but
when those viscera are filled,  the intestine is in the
general  cavity of  the abdomen.

                  The Mesentery

  Is a process of the peritoneum, which is formed in
the manner of a plait or fold, and of course consists
of two lamina. These lamina proceed from the back
part of  the abdomen, and are so near to each other,
that they compose  one substantial  process;  having
cellular  and  adipose  substance, blood  vessels and
nerves,  with  absorbent or lacteal  vessels and  their
glands,  between them.
  The  form  of this  process, when it  is separated
from the back, and  the intestines are detached from
it, is somewhat semicircular : that portion of its mar-
gin or edge which corresponds to the diameter of the
semicircle, is connected to the back of the abdomen,
and called the root of the mesentery; the edge, which
is the cm umference of the semicircle,  is connected
with the intestine.  The edge  connected with the
back of the abdomen is commonly about five or six
inches in length : the semicircular edge, instead of ex-
tending fifteen or eighteen inches,  the ordinary pro-
portion, is attached to a portion of intestine  some-
times twenty-four feet in length.  The mesentery on
account  of this great difference between its diameter
and circumference, has been compared to theruflieofa
shirt sleeve; its roots being taken for the plaited edge
of the ruffle, and the circumference for its loose edge.
But the comparison is not precisely accurate;  for the
mesentery is not plaited  at its  root, but  perfectly 
116           Root of the Mesentery.

smooth, and free from every kind of fold.   It begins
to enlarge towards its circumference, and enlarges to
that degree,  that it falls into plaits or folds: precisely
such as would  exist in a semicircular piece of mem-
brane about six inches in diameter, if a number of
simple incisions, of about an inch and a half in length;
were  made in a radiated direction from its circumfer
ence, and if portions like a sextant or quadrant were
taken from a circular membrane three  inches  in  di-
ameter, and united by their edges to these incisions,
so that their circumference might be continuous with
the circumference of the large semicircular piece. In
this case,  the  portions  like  quadrants or sextants
would assume a folded position like  the edge  of  the
mesentery, while the middle of the semicircular piece
would preserve its regular form without folds; as is
the case with the mesentery at some distance  within
its circumference.   By  many additions of this kind,
the circumference of a membrane, which was original-
ly a semicircle of five or six inches, may be extended
so as  to exceed greatly that of the mesentery.   It
seems of course impossible  to  form an accurate mo-
del of the mesentery with a. single piece of membrane
or paper; but it  may be easily made with clay, or
any ductile substance.  A model  of this kind must
necessarily be folded after the  manner of the  mesen-
tery ; and its circumference, like the mesentery, would
appear as if formed of portions of the circumference
of smaller circles united  to each other.*
   The  root  of the  mesentery commences  with the
jejunum on the  lower side of the mesocolon,  at the
left of the spine, and  extends  downwards near  to
the right iliac region ; crossing the spine obliquely.

   * A model, upon the plan first mentioned, was invented by Dr. J. G.
 Shippen.  It has been proposed, I believe by M. Gavard, to  make one
 with a single piece of buckskin, of a semicircular form, by stretching it at
 the circumference. 
      Appearances of the Csecum and Colon.   117

When it is examined in its* natural situation, the peri-
toneum is found continued from  the back of the ab-
domen to the intestine ;  it then surrounds the intes-
tine, and continues  from it to the back of the abdo-
men again.   There must therefore be  two lamina of
peritoneum in the mesentery, and there must  be a
small  portion of intestine answering to the  interstice
between these lamina, which is not covered by the
peritoneum.  The  blood  vessels,  and absorbent or
lacteals,  pass  most commodiously to the  intestines
between these lamina;  for  they are connected with
large  trunks that  lie on  or  near the spine, and the
root of the mesentery commences there.
  The glands connected with the lacteals or absorb-
ents are  very conspicuous in the mesentery, and are
commonly  called  mesenteric glands.   They are of
different sizes, from more than  ha.I an inch to one or
'two lines in diameter.   They are very  numerous,
and scattered irregularly, but  are  seldom  observed
very near to the intestine.   They are often enlarged
in consequence of disease, especially in children.
  The nerves of  the small  intestines which are de-
rived principally  from the superior mesenteric  plex-
us, are also to be found  here.
   The adipose matter between the lamina of the me-
sentery is very often in a large quantity, but varies,
in proportion to the general quantity of adeps in the
subject.
            OF THE GREAT  INTESTINES.

              The Csecum and Colon

   Are very different from the small intestines in
many respects.   They  are much larger in diameter.
Their external surface is marked by three longitudi-
nal bands of a light colour,  which extend the great-
est part of their length, and  are  placed nearly at 
118
Position of the Csecum.
equal distances  from each  other.   The  spaces  be-
tween these bands are marked by transverse inden-
tations,  which  pass  from one band to the other at
short but unequal distances.  At these indentations
the coats of the intestine are pressed inwards, as if a
fine  thread had  been drawn  round it externally,
while the spaces between them are full jbluA  tumid,
and on this account are called cells.
  The great intestine,  with these appearances,  be-
gins, as has been already observed, in the right iliac
region, by a rounded end which  rests  on the fossa
or concave surface formed by the  costa of the  ileum;
from this it is continued upwards in the right lum-
bar region, anterior to  the kidney, until it arrives
near the liver, when it forms a  curve, and passes
directly across the abdomen to the left side.   In this
course it approaches so near to  the  under  side of
the liver, that it is often in  contact with it, and with
the gall-bladder,  which, after death, tinges it with a
yellow colour.  On the  left  side  it passes down  the
lumbar  region, before the kidney,  to the left iliac
region;  here  it  is  curved so as to resemble  the
Roman letter S, inverted;  this curve generally car-
ries it to the right side of the spine, and then brings
it back to  the  centre of the sacrum.   Here the in-
testine  changes  its course, and  passing  into,  the
pelvis, continues  downward, in  contact  with  the
sacrum and coccygis, and partaking of the curvature
of those bones, until it terminates at the anus, where
it is connected with  the sphincter and levator  ani
muscles.
  About two inches from the  commencement of  the
great intestine the ileum opens into it laterally; and
all that portion which is between its commencement
and the insertion of  the  ileum is  termed Caecum, or
the blind intestine:  that  part of the great tube,
which is included in its course from the insertion of 
Structure of the Colon.          119
the ileum  to the  posterior part of the  brim of the
pelvis, is called Colon ; and the remainder,  or the
part which is contained in the pelvis, is termed Rec-
tum.  •
  The Csecum is nearly as wide as it is long;  it is
fixed in the right  iliac  fossa by  the  peritoneum,
which invests it so that the great body of the intes-
tine projects from the surface of the fossa covered
by the peritoneum ; but a portion is in  close con-
tact with the surface, and connected to it by cellu-
lar membrane.   Its external surface, covered by the
peritoneum, is marked  by two  of the  bands or
stripes before mentioned, which proceed on it  length-
ways.  These bands are in full view, but the  third
band is generally on that part  of the intestine which
rests on the iliac fossa, and is  therefore  out of sight.
At the rounded  extremity of the csecum,  situated
anteriorly and internally,  is a small process resem-
bling an earth-worm in form and size :   this is there-
fore called Appendicula Vermiformis.  It is hollow
and communicates with the cavity of the caecum at
the place  of junction ; and like  the csecum, has its
other  extremity  closed up.   It is composed of the
same number of coats and has the same structure as
the great intestine : its length varies from two to four
inches.
   The longitudinal bands above mentioned commence
at the junction of this appendix with the caecum, and
continue throughout the extent of the colon.   They
appear to be formed by some of the longitudinal  fibres
of the muscular coat, which are arranged close to each
other. These fibres seem to be shorter than the coats
of the intestine, and the interior coats  adhere firmly
to them.  Thus are produced the indentations and
cells; for if the bands are divided transversely, the
indentations disappear, and the surface of the intes- 
120             Valve of the Colon.
 tine becomes uniform.  One of these bands is cover-
 ed bv the mesocolon.
   The circular or transverse fibres of the muscular
 coat of the csecum and  colon are very delicate, and
 not numerous.
   The internal coat differs materially from that of the
 small intestines, although at first view they seem to
 resemble each other: for if a portion of the ileum and
 of the colon he inverted and suspended in water, no
 villi can be seen with the naked eye on the internal
 coat of the colon, while those of the ileum are very
 visible.   The glands exterior to this coat are larger
 than those on the small  intestines.
   Instead of valvulae  conniventes, are the ridges made
 by the indentations or depressions  above  described,
 which separate the incomplete cells from  each other.
 These ridges differ essentiallv from the valvulae con-
 niventes, because all the coats of the intestine are con-
 cerned in their formation, whereas the valvulae conni-
 ventes are formed by the villous coat only; they also
 project into the cavity of the intestine, while the val-
 vulae are  laid on its  surface.  They pass only  from
 one longitudinal hand to  another, and, in consequence
 of this, the cells are  small, and the position of  each
 band is very evident  when the intestine is laid open.
   The communication of the ileum  with  the great
 intestine  has  been already stated to be on the left
 side of it, about two  inches from its commencement.
 The aperture is so constructed, that it is  considered
 as a valve, and is called  the Valve of Bauhin. or of
 Tulpius,  after the anatomists  who  have described
 it.*   The appearance of the aperture is  as follows:
 If the caecum, with a small portion of the ileum and

  * Posthitis in 1566; Vidus Vidius about 1569; Alberti in 1581, and Varo-
fius who died in 1575, each lay claims to the discovery of it  Bauhin'a
claims are in 1579. Ed. 
       Structure of the Valve of the Colon.    121

of the colon, be separated from the other intestines,
and kept in an inflated state until it  be so dry as to
preserve its form when opened, and then if the cae-
cum and colon be laid  open opposite to the aperture
of the ileum, a large  transverse  ridge, resembling
some of the ridges or folds just  described, will be
seen projecting into the cavity of  the intestine.  In
the internal edge of this fold is a long slit or opening,
which forms the communication between the two in-
testines.  It is obvious  that the form of this fold must
be that of a crescent;  and that its two surfaces with
the slit between them,   must have  the appearance of
two lips, which would  readily permit a fluid or sub-
stance of soft consistence to  pass from the ileum into
the great intestines, but must impede,  if not prevent,
its passage  back; especially if the large  intestines
were distended, as then  the  lips would be pressed
against each other.
  When the peritoneal coat is  dissected  from each
of the intestines at their place of junction, and this
structure is  then examined from without, it appears
as if a transverse  or  half circular indentation had
been formed by the villous coat of the great intestine,
and that the internal  eoat  of the extremity of the
ileum was pressed into this indentation, and united
to the internal coat of the great intestine which form-
ed it; while there was a slit, both in the indentation
and in the end of the ileum, which formed a commu-
nication between the cavity  of the great intestine and
the ileum.  The longitudinal fibres of both intestines,
as well as their external coats, seemed to be united,
so as to form a common cover for them;  while the
circular fibres were blended in the two portions of
the indentation which form the lips of the orifice.
  This orifice is, of course, transverse with respect
to the intestine.   It has been observed, that there
was a difference in the thickness and strength of the
  Vol. ii.               16 
\2\i          Position of the Rectum.

two lips or valves;  that the lower  valve  was the
strongest, and appeared to have the largest propor-
tion of muscular fibres in its  composition.  At the
extremities of the orifice, and near each end of the
fold  or  ridge,  are  tendinous  fibres, which  give
strength to the structure; they are called the Reti-
nacula of Morgagni, as they were first described by
that anatomist.
  There is great reason for believing that this valve
cannot prevent the retrograde motion of the contents
of the intestines in all cases ; for in  some instances
of hernia and of colic, matter perfectly stercoraceous
has been vomited, and the probable inference from
such a state of the ejected matter is, that this matter
has been in the large intestines.  It is also said, that
suppositories and enemata have been discharged by
vomiting.
  On the right and left sides of the abdomen, the
colon  is in close contact with the posterior surface of
the cavity.   The peritoneum, which covers this sur-
face, extends over the intestine also, and thus retains
it in its position.  The great arch of the colon, which
is loose and moves far from the back of the abdomen,
is invested by the two lamina of the omentum, which,
after surrounding it, unite again and form the meso-
colon.   Connected with  the exterior surface of the
colon  are many processes, composed of adipose mem-
brane, varying in length  from  half an inch to an inch
and a half:  these appear to be of the nature of the
omentum, and are  therefore generally denominated
Appendices Epiploicae.

                   The Rectum.

  After forming the sigmoid flexure, the colon ter-
minates; and the  rectum  begins opposite to the lower
surface  of the last lumbar vertebra, and nearly in
contact  with it;  from this it  proceeds downwards, 
             Structure of the Rectum.         123

forming a curve like the sacrum, until it terminates
at the anus, where  it is invested with the  muscles
called the sphincter,  and levator ani.   It  is called
rectum, because in  this course it is supposed not to
incline to either side; but it is  often found on one
side of the middle  line.*
  This intestine being in contact with the posterior
surface of the pelvis, is covered, on its anterior sur-
face only, by the peritoneum which lines the poste-
rior surface of the pelvis; and it is fixed in this situ-
ation by  the peritoneum, as the colon is on the right
and left sides of the abdomen, but more loosely; and
therefore the term  Mesorectum has sometimes  been
applied to that portion of the peritoneum which  is
analogous to the mesentery and mesocolon.   The pe-
ritoneum does not extend to the end of the  rectum;
for it is  reflected at the lower part of the pelvis from
the rectum to the bladder, or uterus, and  does not
line the  bottom of the pelvis; so that the lower part
of  this  intestine, as well as of the  other viscera  of
the pelvis, is below the peritoneum, and not connect-
ed  with it.
  The muscular coat of the  rectum is much thicker
and stronger than that  of any other intestine.   The
strata of longitudinal and circular fibres which com-
pose it are very distinct from each other.   The lon-
gitudinal fibres are most numerous,  and terminate  at
the insertion of the fibres of the levator ani muscle.
The lower  circular fibres are  intimately connected
with the sphincter  ani.
  The internal coat is very  vascular,  but the villous
structure is not apparent.    Mucous follicles are also
very numerous; and  there are likewise some distinct
glandular bodies exterior to  this coat, which vary  in
size in different subjects.
  *  Morgagni and Haller supposed it to be commonly on the left of  the
middle line: and Sabatier on the right. 
124 Absorbents and Nerves of the Intestines.

   The quantity of mucous discharged from the rec-
tum in certain cases of disease, is  sometimes very
great.  The internal coat, in consequence of the con-
traction  of the circular  fibres exterior to it, some-
times forms longitudinal folds,  which  have been
called its columns ; these  often  disappear when  the
intestine is opened lengthways and spread out.   By
the contraction of the longitudinal fibres, the internal
coat is often thrown into  folds or  doublings,  that
must assume a  transverse or circular  direction ; they
occasionally pass down through the sphincter, and
form the prolapsus ani.   The  rectum is most plenti-
fully supplied  with blood vessels,  to be described
hereafter;  and it may be  observed, that, on the low-
er part of the internal coat,  the veins are particular-
ly numerous.
   The internal  coat  of  the rectum  terminates  ab-
ruptly just within the anus, and is united to a pro-
duction of  the  skin, which,  like the  covering of  the
lips, is very delicate  and vascular,  and  has  an epi-
thelium,  or very thin  cuticle, spread  over it.  The
levator and sphincter ani  muscles, with which  the
termination of  the rectum is invested, are described
in the first volume.
   The Absorbents of the Intestines  are commonly
denominated Lacteals.*   They originate on the in-
ternal surfaces  of  these viscera, as has  been already
described.    After passing through the lymphatic
glands, which  are so numerous on  the  mesentery,
they generally  unite and form one of the great trunks
which  compose the thoracic  duct.   It is asserted,
that some of the  absorbent vessels of the lower in-
testines unite to the lymphatics of the loins.

  * The lacteals were first observed by Erasistratus and Herophilus, of
the school of Alexandria, during the reign of the Plotemies ; and subse-
quently by Aselli, of Pavia, in 1622, the knowledge of them having been
lost for 1900 years__Ed. 
  Origin and Arrangement of the Omentum.  125

  The Nerves of the Intestines  are principally de-
rived from the intercostals, or great  sympathetics
From each of these nerves, while they are in the tho-
rax, an important branch, called  the ramus splanch-
nicus, arises.  These splanchnic branches pass through
the diaphragm, and are the chief contributors to the
ganglions and plexuses formed in the  abdomen.  A
plexus, derived from this source surrounds the supe-
rior mesenteric artery, and another the inferior me-
senteric ;  and from these proceeds  the nerves of the
intestines.
                  The Omentum

  Requires a separate description,   although several
circumstances connected with its structure have been
already noticed.  It often varies in its position; but
when it is rendered firm by a quantity of adipose mat-
ter, it is spread over the intestines  like an apron, ex-
tending from the  lower edge, or great curvature of
the stomach,  towards the bottom of the abdomen.
  As has been already said, it is an extension of the
peritoneum, in two lamina, from  the concave surface
of the liver to the lesser  curvature of the stomach ;
and  these lamina, after surrounding the stomach,
come in contact with each other near its great curva-
ture.  From this portion of the stomach, from the
commencement of the duodenum, and also from the
spleen, the Omentum, composed of two lamina de-
scends over the colon and the small intestines more
or less low into the abdomen; it  is  then folded back-
wards and upwards,  and is continued until it meets
the great arch in  the colon :  here   the lamina again
separate and  enclose that portion of the intestine, on
the posterior side of which they again approach each
other, and form a membrane like the  mesentery,  of
two lamina, which passes from the concave  or  pos-
terior surface of the colon  to the  back of the abdo- 
126  Origin and Arrangement of the Omentum.

men, where it is continued into the membrane which
lines that surface.  This  last portion is the Mesoco-
lon : the portion between the liver  and stomach is
called  the   Omentum  of Winslow,  or the lesser
omentum; and  the great portion between  the sto-
mach and colon is called the Great Omentum, or the
omentum gastro colicum.  There is also a  process
of peritoneum  continued from that  portion of the
colon which is on the right side of the abdomen, and
from the caecum, which extends to  some distance;
it is formed of two lamina, that compose a cavity of
an angular form.  This has  been called the Omen-
tum Colicum.
  The great and small omentum, with a portion of
the peritoneum on the  back of the abdomen, form a
sac, which encloses a distinct cavity in the abdomen.
The anterior  part of  this  sac is composed of two
lamina, and  between  these  lamina are the stomach
and the great arch of the colon.  This cavity, form-
ed by the two omenta,  communicates with the gene-
ral cavity of the abdomen by a foramen of a semicir-
cular form, called the Foramen of Winslow, which
is behind the great cord of the vessels that go to the
liver.
  The omentum is so  delicate in  structure,  that
when free  from fat,  it is very liable  to laceration
merely by adhering to the fingers,  if they are dry.
Winslow therefore advised that some  unctuous sub-
stance should be rubbed on  the hands, before  they
were applied to it.
  The appearance of the great omentum is very dif-
ferent  in different persons.    In the emaciated, it
appears  like a delicate transparent  membrane ; in
the corpulent, it is like a broad mass of adeps, which
sometimes is very thick.  When it  is thus loaded
with adeps, it is most commonly spread over the
small intestines : when  it is free from  fat, it is often 
Varieties in the Appearance of the Omentum.  127

compressed together, so as to form a small mass near
the arch of the colon, on the left side.
  The  principal  blood vessels of the omentum are
derived from those of the stomach, and are called gas-
tro epiploic arteries and veins.
  The use of this membrane in the  animal economy
has not been  ascertained with certainty.   It seems
probable that one of its principal objects is to protect
the small intestines, and lessen the friction consequent
upon their motion;  but it has been supposed to an-
swer several other important purposes.*

     * See Halleri Elementa Physiologiae, vol. vi. page 381.
     Gavard. Traite de Splanchnologie, page 350.
     Dr. James Rush's Inquiry into the use of the Omentum. 
CHAPTER HI.
 OF THE LIVER, THE PANCREAS, AND THE SPLEEN.

                    SECTION I.

                  Of the Liver.

  This largest viscus of the abdomen, when in a
healthy condition, is of a reddish-brown colour.  If it
is taken out of the subject, and laid on a flat surface,
it is flat, but in the abdomen it is convex  and concave.
  It is situated in the right hypochondriac region,
which it occupies entirely; and extends through the
upper portion of the epigastric into the left hypochon-
driac region.  Being placed  immediately under the
diaphragm, and in close contact with it, as well as with
the inner surface of the right hypochondriac region,
it partakes of their form, and is convex above and
concave below.  When thus situated, it  is of an irre-
gular figure, between the circular and the oval, but it
is broader at the right extremity than at the left, and
very irregular  in thickness.   The edge or margin
which is in contact with the posterior part of the right
hypochondriac region, is very thick. It gradually be-
comes thinner towards  the left, and also towards the
front; so that the right margin, and a large portion
of the posterior margin, is very thick, while the left
and the anterior margin is thin.
  The  upper convex  surface of the liver, when in
its natural  situation, is smooth: the lower concave
surface is marked by several grooves or  fissures and
eminences.   One of these, called the Umbilical or
the great fissure, commences at a notch  in  the ante- 
         Lobes and Fissures of the Liver.     129

rior edge of the liver, to the left of the middle, and
continues to the posterior edge.   At the commence-
ment of  this fissure the umbilical ligament enters ;
and at the termination, or  near it, the vena cava is
situated.  Opposite to this fissure, on the upper or
convex surface, is a ligament passing  from the dia-
phragm  to  the liver, which is called  the falciform.
The fissure  and the ligament divide the liver into its
two great lobes, the Right and Left.
   Another  great fissure,  called  the  transverse or
principal, commences in the right lobe and extends
to the  left, crossing  the  first mentioned  fissure at
right angles,  and extending  a  very short distance
beyond it.   It is very deep, and rather  nearer to
the posterior than the anterior edge of the liver.  In
this fissure,  near to  its right  extremity,  the great
vein, called  vena portarum, and  the hepatic artery
enter,  and the excretory duct of the liver, commonly
called the hepatic duct, comes out.   About the mid-
dle of  the fissure are  two  prominences, one on each
side; these  were called the portae,  or  gates of the
liver, and hence the great vein was called  vena por-
tarum.   This vein  has two  very large rectangular
branches, which constitute what  is called  the sinus
of the  vena portarum, and they occupy the principal
extent of the fissure.
   The  liver is in  close contact with the  vena  cava
behind;  and there is either a groove in it for the pas-
sage of the vein, or this great vessel is completely en-
closed  by it.  There is also an  excavation  on the
lower surface  of  the  liver, which is occupied  by a
portion of the gall bladder.
  Besides the  great  lobes above  mentioned, there
are also two  or three prominent parts on the concave
surface, which are denominated lobes.  One of these,
called Lobulus Spigelii, is oblong, with two sides,
and  an  angle  continued  along  its whole length,
   Vol. u.               17 
130         Ligaments of the Liver.

which extends from the transverse fissure to the pos-
terior margin of the liver.  It is situated between
the posterior part of the transverse fissure, or ductus
venosus, and the vena cava.
  The anterior extremity of this lobe, which forms
one of the margins of the transverse fissure, is some-
what bifurcated, and has been called lobulus caudatus.
The largest portion of the bifurcated end forms a pro-
cess like a papilla, and is one of the portae.
  Between the umbilical fissure and the depression
for the gall  bladder is a protuberant space,  which
varies from  an inch and a quarter to  two inches in
breadth.  This has also been called a lobe, Lobulus
Quartus or Anonymous, its posterior point opposite
the papilla of the  lobulus spigelii forms the other
porta of the liver.
  The  peritoneum is extended from the surface of
the abdomen to the surface of the liver, in such man-
ner as to cover it, and to form ligaments, which have
a great effect in retaining it in  its proper situation.
The whole posterior edge of the liver is in contact
with  the  back of the abdomen.  The  peritoneum
above the liver is reflected to the upper surface of it,
and the peritoneum below it to the lower surface;
so that two lamina of  the  peritoneum  pass from the
lower part of the diaphragm at the back of the abdo-
men to the posterior edge of the  liver.  These pro-
cesses of the peritoneum  are considered as forming
two ligaments, which are called the  right and left
lateral ligaments.  A portion of the posterior surface
of the liver, uncovered by the peritoneum, is often in
contact with a portion of the tendon of the diaphragm,
also uncovered by peritoneum : around this place of
contact,  the  peritoneum  is extended from the dia-
 phragm to the liver,  and thus forms what has been
called the coronary ligament of the liver.
   The peritoneum of the right side of the diaphragm,
 and of the abdominal muscles, as  far down  as the 
          Mode of supporting the Liver.       131

umbilicus,  is extended to the liver, and joins it on
the convex surface immediately opposite  to the  um-
bilical fissure.  The peritoneum from the left side of
these parts does the same ; and as these reflections
of the peritoneum are continued from so low a part
as the umbilicus, they are extended not only to the
convex  surface of  the  liver,  but  also  to  the great
notch, and along the umbilical fissure.
   From the umbilicus proceeds a round cord-like lig-
ament,  which  in  the  foetal state was a vein,  that
passes to the great fissure of the liver, and along it.
The process of the peritoneum above  mentioned is
so connected with this cord, that it encloses it in its
lower edge, and the whole is  called the falciform
ligament of the liver.  The cord, when named se-
parately, is the umbilical or the round ligament;  and
the membrane or lamina  of the peritoneum forms the
suspensory ligament.  Besides these, the peritoneum
on the lower side of  the  liver is so arranged, that it
not only extends to the stomach, but to the duodenum
and the colon.
  By these ligaments the position  of the liver must
be fixed to a great degree; and there is one additional
connexion, which must have a great effect in retain-
ing it in its proper situation. The vena cava receives
two or three great veins  from the liver, at the place
where it is in contact with the posterior edge of that
viscus :  these veins of course pass directly from  the
substance of the liver into the cava, and connect it to
that vessel.   As the cava is supported by the heart,
and also by the diaphragm, it must afford a consider-
able support to the liver.
  When the stomach and intestines are distended,
they must also contribute  in a considerable degree to
the support of the liver.
  The liver has  a strong tendency, when  we are
erect, to change its situation; and some considerable 
132 Acini of the Lever.—Proper Coat of the Liver.

support is necessary to counteract this tendency.   It
would move to the right, when we  lie on  the right
side, if it were not in contact with  the ribs ; and it
inclines to the  left, for want of such  support, when
we lie on the left side.
   It  has been  computed,  that the  liver descends
about two inches, when  the position of the subject is
changed from the horizontal  to the erect.   As it is
in contact with the diaphragm, it is obvious that it
must  be influenced by  the  motions of that  muscle,
and that it must descend when the diaphragm con-
tracts.
   The liver  is composed of a substance which  has
some  firmness of consistence, although it  is yielding;
and is also somewhat brittle or friable.*   When cut
into,  the sections  of many tubes, or vessels  of  dif-
ferent diameters, appear on the cut surface.   When
the texture  of  this substance is more  closely  ex-
amined,  it  appears  somewhat granulated, or com-
posed of very small bodies, which were  called acini
by the anatomists who  first  described them.  The
whole substance is enclosed by the peritoneum, which
is extended to it from the surface of  the abdomen in
the manner that has been already described.   It has
also a proper coat or capsule  ;  and on the posterior
edge, where the lamina of the lateral ligaments pass
from  the diaphragm to  the liver,  at some  distance
from  each other, a portion of the liver, covered by
this coat and by cellular substance, is in  contact with
the diaphragm.  The same thing occurs likewise at
the coronary ligament.f
   The liver holds the first place among the glands

   * It has been fractured in the living body by external violence.
   f Many anatomists deny the existence of this coat;  but if one of the
lamina of the ligaments be carefully peeled off from the surface of a
liver which is slightly affected by putrefaction, it will be apparent, al-
though very thin.  It was described  by M. Laennec, in Le Journal de
Medecine for 1803. 
Vessels of the Liver.
Hepatic Artery.   133
of the body for size, but it is still  more remarkable
for some other circumstances  in its economy.    In
addition to an artery, which passes to it as arteries
do to other  glands, there is a large vein which  also
enters it as an artery;  and after ramifying through-
out the liver, communicates, as does the artery, with
other veins, which carry the blood from this gland
into the vena  cava and the  general circulation.
There are therefore three species of blood vessels in
the liver; and with these are found the vessels which
carry out of the gland the fluid secreted by it, or the
bile.
   The artery of the liver is denominated the Hepa-
tic Artery.   The  vein which goes  to the liver is call-
ed the  Vena Portarum, from the place at which it
enters.   The veins which carry to the vena cava the
blood brought to the liver by  the hepatic artery and
the vena  portarum, are called the Hepatic Veins;
and the duct through which the bile  flows out of the
liver, is called the Hepatic Duct.  Three of  these
vessels, the Hepatic Artery,  the Vena Portarum,
and the Hepatic Duct, enter  the  liver at the great
fissure, at the spot where the prominences  exist call-
ed the portae ; hence  the name vena portarum  was
applied to the  vein.
   These vessels ramify in the manner presently to be
described ; and it  is ascertained by minute anatomical
investigation, that the liver is entirely composed of the
ramifications of these vessels and of the hepatic veins,
with absorbent vessels and nerves,  which are connect-
ed together by cellular membrane.
   It has been  already observed, that the  first great
 branch sent off by the aorta in the abdomen,  the Ce-
 liac, divides into three branches, which go respective-
 ly to the  stomach, the liver, and the spleen.
    The Hepatic  is  generally the largest of  these
 branches.   In its  progress towards the liver it sends 
134
Vena Porta?~am.
off an artery to the stomach, called the gastrica dex-
tra. At the great fissure it divides into two branches:
the right branch, which supplie> the right lobe of the
liver, is of course the largest.  This branch sends off
one to the  gall-bladder, which is called the cystic  ar-
tery ;  and also some smaller branches: it passes un-
der the hepatic duct, and ramifies through the great
lobe of the liver.   The left branch is  distributed
through the left lobe of the viscus.  It can be proved
by injection, that the hepatic artery communicates not
only with the hepatic veins, but with the biliary duct,
and the vena  portarum also.   It  has  been disputed
whether the size of this artery is greater  than  would
be requisite for the nourishment and animation  of the
liver.
   The  Vena Portarum, the great peculiarity  of the
liver, originates from all the chylopoietic viscera ex-
cept the liver, and is of course  formed by the union
of the veins which correspond to all the branches of
the cceliac  and mesenteric arteries, as they are dis-
tributed to the stomach and intestines, the spleen,
the pancreas, and  the  omentum.  The  veins from
the intestines generally form two great trunks,  which
are denominated  the  greater and lesser  mesenteric
veins.   The great mesenteric vein is situated  to the
right,  and rather before the mesenteric artery.—
After it has approached the origin of the artery it
separates from it, and passes behind  the pancreas:
at this place, nearly in front of the spine, it is joined
by the great vein of the spleen, which forms almost
a right angle with it, and these constitute the  great
trunk of the vena portarum.  The lesser mesenteric
vein,  which corresponds to  the inferior mesenteric
artery, and brings blood from the pelvis and from
the left  part  of the  colon,  becomes finally a. large
vessel, and commonly unites with the splenic  about
an inch and a  half before its junction with the supe- 
         Vena Portarum.—Hepatic Duct.      135

nor  mesenteric vein.   The  vena  portarum, thus
formed, proceeds towards the liver, inclining to the
right, and is generally about three inches in length:
in its course it sometimes receives small veins, which
in other cases pass  to  its splenic  and  mesenteric
branches.  When it has arrived  at the great trans-
verse sinus of the liver, it divides into two large
branches, each of  which forms nearly a right angle
with it.  Their size is so great, that, when distend-
ed with injection, they appear like  an independent
vessel, into which the vena  portarum enters;  and on
this account they are called  the great  Sinus of the
vena portarum.   They do not adhere  firmly to the
glandular substance of the liver,  but are united to it
by cellular membrane.   The right branch  is the
widest and shortest.  It generally divides into three
branches;  an anterior, a  posterior,  and a  lateral
branch; which  ramify minutely, and  extend them-
selves in the right lobe.  The left  branch is much
longer, and continues to the extent of  the transverse
fissure.  Near its termination it is joined by the um-
bilical ligament, which has been  already mentioned.
This branch is generally in  contact with a branch of
the hepatic artery and of the hepatic duct;  and ra-
mifies, like the right branch, into  the contiguous parts
of the liver.
   The Hepatic or excretory duct originates, by very
small vessels,  from the  acini  or corpuscles of which
the liver is composed, and into which the minute ra-
mifications of the vena portarum and  hepatic artery
extend.  They accompany  these vessels, increasing
as they increase, although the fluid they contain moves
in  an  opposite direction ;  and  two large  branches
which they ultimately form are situated at the port*
 of the liver, in contact with  the great branches of the
 vena portarum and the hepatic artery.
   These three vessels are in contact with each other 
136  Hepatic Veins.-—Nerves of the Liver.

before they enter the liver.   The biliary duct is an-
terior, the vena portarum posterior, and the artery to
the left of them.   They are accompanied by nerves
and lymphatic vessels, and are surrounded by a con-
siderable quantity of cellular substance, and thus ar-
ranged are partially covered with peritoneum.  The
cellular substance which invests them continues with
them into the  liver, and is more particularly con-
nected with the vena portarum.   It is called Glis-
son's Capsule,  and was supposed to  have some con-
tractile power, which assisted the circulation of the
vena  portarum; but that idea is now altogether aban-
doned.   The hepatic veins, which receive the bloaj
of the hepatic  artery and the vena portarum, open
into the anterior part of the vena cava, where it is
in contact with  the liver.  Generally there are three
of these veins, but  sometimes there are only two;
in which case one of them  is formed by two others,
which unite immediately before  they open into the
vena  cava.  It is  to be observed,  that the various
branches of these  veins do not  accompany those
branches of the vena portarum or  hepatic artery to
which they correspond, but form  very large angles
with  them.   This is  probably owing merely to
their  termination  in a  part so distant from that in
which the artery and the vena portarum originate;
but it is very different from what  occurs  in  other
glands.
  The Nerves of the  Liver are derived from the
similunar ganglions of the splanchnic nerves.   From
these many nerves proceed,  which  form a net-work
denominated the  solar  plexus.   From this plexus
many threads  are sent off,  which  form a net-work
that is divided into the right and left hepatic plexus.
These plexuses surround the hepatic artery and the
vena portarum, and accompany them in their ramifi-
cations throughout the liver, being enclosed by Glis- 
Lymphatics.
137
son's capsule.   They receive some threads from the
stomachic plexus,  formed by the par  vagum.   Al-
though the number of nervous fibres is  very conside-
rable, their bulk, compared with that of the liver, is
very small.
  The Lymphatics of the Liver are extremely nu-
merous ; and those in that portion of the peritoneum
which invests  the liver may easily be rendered con-
spicuous:  for by pressure the injected  fluid can be
forced from the trunks and large branches into the
small ramifications, in opposition to the valves.  When
all the surface is injected in  this manner,  it has the
colour of the substance  injected; as is  the  case with
parts which are very vascular, when the blood ves-
sels are injected.
   The deep-seated lymphatics are* also very numer-
ous in the  liver, and communicate freely with the su-
perficial.
   The superficial lymphatics which are on the upper
surface, proceed through ftie diaphragm into the tho-
rax in their course to the thoracic duct.  Those which
are deep-seated emerge from the liver at the portae,
where the great vessels enter, and unite with the tho-
racic duct  in the abdomen, after passing through se-
veral glands.   The lymphatics of the  lower  surface
unite with the deep-seated.
   The glandular or parenchymatous substance of .the
liver is of a reddish-brown colour,  and  moderately
firm consistence.  When it is cut into, the cut surface
exhibits the sections of the branches of the different
blood vessels above mentioned,  and  of  the  excretory
ducts.   These vessels are often distinguishable from
each other.  The section of the biliary duct appears
the thickest; that of the artery next;  the  vena por-
tarum  is next in order; and, last of  all;  the venae
hepaticac.           •
   VOL. u.              18 
138
Glandular Substance of the Liver.
   The branches of the vena portarum are surrounded
by cellular substance, or Glisson's capsule; and there-
fore adhere less to the substance of the liver than the
branches of the hepatic veins.   The sections of the
hepatic ducts have often bile in them, and are there-
fore termed pori biliarii.   The branches of the arte-
ry are also very distinguishable."
   When the internal substance of the liver is brought
into view, and examined accurately, it appears to be
formed of small bodies, or acini,  which are  distin-  ,
guishable from each other.  If the liver happens to
be torn or lacerated, the lacerated surfaces are rougfir *
and  irregular, owing to the separation of these acint
from each other.                                   f *
  It is asserted by  several microscopical observers,
that a  minute bratfch of each of  the aforesaid vessels
can be traced into each of the acini.   It is also  de-
clared, that if each of these vessels be injected sepa-
rately  with mercury, oil of turpentine coloured, or a
saturated aqueous solution  of gutta gamba, there is no
part of the glandular mass  as large as a grain of mus-
tard seed  in which these vessels  will not be found.
  Several anatomists of the first  character have like-
wise declared, that a fluid  properly injected into  one
of these  vessels, will  occasionally  pass  into' all of
them.   Thus an injection will not only pass from the
vena portarum to the biliary duct, but to the hepatic
artery  and veins also.   It  will likewise pass, in a re-
trograde course,  from the biliary ducts to the vena
portarum,  and to the hepatic artery and the hepatic
veins;  or from any one of the four orders of vessels
into  the three others.*
  The great peculiarity of the liver is, that venous
blood,  instead of arterial, is brought to it for  the
purpose of secretion.   Thus, the great vein of  the
                           •  •
  * I have tried the experiment and find the assertion to be correct.—Ed. 
     Peculiarity of the Liver.—Gall Bladder. 139

chyjopoietic viscera, instead of  passing to the  cava,
enters the liver by the  transverse  fissure, and takes
on the office of an artery; its coats, ort this account,
being much thicker and stronger  than  those of the
hepatic veins.*
  The Biliary or Hepatic Duct  is formed of very
minute vessels, which originate in the  acini  above
described; these unite together like veins until they
form considerable branches,  which  finally  compose
the  great ramifications  of  the  biliary duct.   This
duct is very strong and firm, and on its internal sur-
face are  the  orifices  of many mucous follicles or
ducts.  It passes from the transverse fissure of the.
liver,  with the hepatic artery, as  before described,
and at the distance of  an  inch and a  half or two
inches from the fissure, it unites with a duct from the
gall bladder, which is  called the Cystic Duct.   This
duct is nearly equal in length to the hepatic, and af-
ter running almost parallel  to it, at length unites so
as to form an acute angle with it.  The  cystic duct
is smaller than the hepatic, and they unite much like
two branches of an artery.  •
  The Gall Bladder, from  which  the  cystic duct
arises,  has the shape of a pear,  with  a very long
neck, curved in a way to be hereafter described.  It
is situated in a superficial pit or cavity in  the con-
cave surface of the right lobe of the liver; and its
fundus, or basis, often projects a  small distance be-
yond the  anterior edge of  the viscus.   Its  position
is such,  that it extends from before backwards, and
inclines rather to the left; of course, therefore, when
the subject lies on his  back, the bottom of  the blad-

  * A case  is related by Mr. Abernethy, in the London Philosophical
Transactions, in which the vena portarum terminated in the vena cava be-
low the liver, without commmunicating with it. The hepatic artery was the
only vessel which carried blood to the organ, and was unusually large; the
liver being nearly of the natural 6ize.  Some bile was in the gall bladder,
but it was leas acrid than usual. 
140     .          Gall Bladder,
der is the uppermost part of it; when he lies on the
left side, it is also higher than the neck ;  and when
he lies on the right side it is the lowermost.
  The gall bladder consists of an internal coat, and
one that is cellular or nervous, and has somewhat of
a fibrous appearance.   This coat  connects the gall
bladder to the surface of the pit or cavity in which
it lies.  The peritoneal coat of the liver is extended
from the surface of the viscus over that part of the
surface of the gall bladder which  is not in contact
with it.
  The internal coat has a peculiar structure,  with a
faint  resemblance to that of the villous membrane.
It is so arranged  as  to form very fine folds,  which
have various directions: in some places they make
a net-work; in others, as the neck of a bladder, they
are longitudinal.   Many mucous follicles exist on its.
internal surface.
  The neck of the'gall bladder is suddenly bent down
or curved upon itself,  and twisted, so that it resem-
bles the neck of the  swan, when the head of that bird
is applied to one side of its breast.
  A branch of the hepatic artery, which leaves it be-
fore it enters the liver,  is appropriated to the gall
bladder, and is therefore denominated the cystic artery.
The veins corresponding to this artery empty them-
selves into the vena portarum.*  The lymphatic ves-
sels are united to those which are found on the lower
surface of the liver, and the nerves are derived from
the hepatic  plexus.          '           '
  The gall bladder  appears to be merely a reservoir,
into which  bile passes through  its duct in a retro-
grade direction.-  If air be blown through the hepa-
tic  duct from the liver, it  will pass to the gall blad-
der almost as freely as it passes to the duodenum.
  * It has been justly observed by John Bell, that the veins would not ter-
minate thus, if bile w^e secreted by the gall bladder. 
   Ductus Communis Chsledochus.—The Bile. 141

   The biliary duct from the liver, after receiving the
duct from the gall bladder, takes the name of Ductus
Communis Choledochus.   It is wider than either of
the other ducts, and near three inches  in length.  It
passes down before  the vena portarum, and on the
right oi  the hepatic artery, to  the posterior surface
of the right extremity of the pancreas.   It  passes
through  a small portion.of that gland, and then per-
forates the muscular coat of the  duodenum ; after
which it proceeds from half an inch to an  inch be-
tween this coat and the villous, and opens  into the
cavity of the intestine.   The orifice forms a tubercle
which extends lengthways of  the  intestine, and  is
rounded above and pointed  below, with a slit in it.
While this duct is in contact with  the pancreas, a
duct from that gland generally opens into it, so that
the biliary and pancreatic fluids enter the duodenum
by the same  orifice ;  but sometimes the pancreatic
duct opens into the duodenum, by a distinct orifice,
very  near to that of the biliary duct.

    The Bile, or fluid secreted by  the liver, appears to an-
      swer a two-fold purpose in  the animal economy.  It
      produces  a chemical effect* upon the* alimentary mix-
      ture which passes from the stomach through the intes-
      tines ; and it increases the peristaltic motion of those
      important organs.
         By an inverted action of the duodenum, some of this
      fluid is f/equently  carried upwards into the stomach :
      it  then often  produces only slight derangement of the
    ,  functions and sensations connected with that viscous;
      but sometimes violent vertigo, and even convulsions,
      seem  to have arisen  merely from the presence of a
      lar^e quantity of bile in the stomach : for they have
      gone  off completely upon the  discharge  of bile  by
      vomiting.
         Notwithstanding these effects of  bile  in  certain
      cases, in which a  great deal of it exists in the sto-
      mach, it  is often  carried into the mass of blood in
      large quantities, and appears to be mixed with the 
142                The Pancreas.

       serum, and to circulate through the body, without pro-
       ducing  any very sensible  effect: thus many persons
       who are deeply tinged by bile in their blood, experi-
       ence but few effects that can be imputed to the mixture
       of it with the circulating fluids: and neither the brain
       nor the heart appear to be much influenced by the cir-
       cumstance.
        Bile  is miscible with water and with  alcohol, and
       also with oily substances; and it often assumes a green
       colour,  when mixed with* acids.  The colour of the
       alvine discharges, is  derived from the bile, and  they
       are therefore sometimes very green, when the acetous
       fermentation takes place in the contents of the sto-
       mach and bowels.
        It is  asserted by some  chemists,  that ten  parts in
       eleven of the humari bile consists of water ; that albu-
       minous  matter composes about  one forty-sixth part of
       it; and that there is nearly an equal quantity of re-
       sinous matter in it.  There is  also a small  quantity,
       (one part in 244,) of uncombined soda dissolved in it,
       and  a smaller quantity of neutral salts, consisting of
       soda combined with the phosphoric, sulphuric and mu-
       riatic acids.  In  addition to these is a very small
       quantity of phosphate of lime  and of oxide of iron,
       and  some yellow insoluble matter.
        The  bile in the  Gall  Bladder  is  generally more
       viscid than that which is found  in the Hepatic Duct.

                      section n.

   *              Of the Pancreas.

   The pancreas is a  glandular  body,, which has a
strong resemblance  to the  salivary glands in seve-
ral particulars.   It  is  seven inches  in length, "and
is irregularly  oblong  in  its form,  one  extremity
being much larger than the other.   Its large extre-
mity is in  contact with  the  duodenum,  and it ex-
tends  from this intestine  in a transverse direction to
the spleen, to'whieh it is  connected by the omentum
and by blood vessels.    It is not invested  by  the
peritoneum,  but is situated in the space which exists 
The Pancreas,               143
between the two lamina  of  the mesocolon, as they
proceed from tne back of the abdomen, before they
come in contact with each other.  It is anterior to
the aorta and vena cava,  and to the mesenteric vein,
or main branch of the vena portarum ; being connect-
ed to these parts by cellular membrane.  At the right
extremity, which is connected with the duodenum, is
a process of the gland that  extends downwards in
close contact with the intestine.—This  is called the
head of the pancreas, or the lesser prancreas.   .
   The position of the pancreas is such, that  one  of
its surfaces looks forwards and rather upwards, and
the other  backwards and downwards; one  edge is
of course posterior and superior, and the other ante-
rior and inferior.  The  posterior of these edges is
much thicker than  the  other, and  has a groove or
excavation  which is  occupied  by the  splenic blood
vessels.
   This gland differs  from the  other large glands of
the abdomen, inasmuch  as  it has not a large artery
particularly appropriated to it;  but instead of this,
it receives branches from the contiguous arteries.
   The arterial blood of this gland is partly supplied
 by the splenic  artery, which, in its 'course from the
 main trunk of the ccBliac to the spleen, while it is in
 the groove at the edge of the pancreas, sends off into
 the gland one considerable branch  called the great
 pancreatic, and a number of sjnall  branches,  which
 go off in succession.   In addition to these, the pan-
 creas  receives vessels from one of the branches of
 the hepatic artery, before it sends off its great rami-
 fications,  as well as  small twigs from  several other
 contiguous arteries.  The veins  correspond with the
 arteries,  but ultimately are discharged into the vena
 portarum.
    The pancreas resembles the salivary  glands  in 
144
Pancreatic Duct.
eolour, and also in texture; for  it it of a dull white
colour with a tinge of red,  and  it appears to consist
of small bodies of a  granulated form,  which are so
arranged as to" compose  small masses  or lobes  that
are united to each  other  by cellular  membrane-
Each  of  these  granulated  bodies  receives one or
more  small arterial twigs, and* from  it proceeds not
only  a  vein  but a  small   excretory  duct,  which,
uniting with similar  ducts from the adjoining granu-
lated  portions or acini,  forms a larger  duct in  each
lobe or mass;  these  open into the great duct of the
gland, which proceeds  through  it lengthwise  from
the left extremity,  in which it  commences",  to tfee
right.
   This  duct is  situate'd in the body of the gland,
which must be dissected to  bring it into view.   It is
thin and transparent  like  the ducts of the salivary
glands, and is rather larger in diameter than a crow's
quill.  In its progress towards the  right  extremity
of  the  gland it gradually  enlarges, and commonly
receives a branch from the part  called the lessor
pancreas.  It most commonly unites with the  biliary
duct before it opens into the duodenum : sometimes
these ducts open separately, but very near to  each
other.  They penetrate the coats  of the intestine
rather obliquely, and between four and five* inches
from  the pylorus.  This  canal is sometimes called
Dustus Virsungii, af^er an anatomist  who published
a plate of it.
   The pancreas has an irregular surface, and no coat
which covers it  uniformly.  It is invested by cellular
membrane, which also connects its different lobes to
each  other. Absorbent vessels and nerves are traced
into it.
   The portion called the lesser pancreas  adheres to
the duodenum,  and when  it is enlarged by disease? 
Size of the Spleen.
145
the passage of aliment through that intestine is much
impeded,.and sometimes completely obstructed.*
  It is now generally believed that the fluid secreted
by the pancreas is similar to that which is  produced
by the salivary glands.

                    SECTION III.

                  Of the Spleen.

  The Spleen is a flat body of  a  bluish colour, and
an irregular oblong form, with thick edges,  which are
indented in some places.
  It is various in different subjects, both in size and
form.  Its most common size is between four and five
inches  in length,  and  about three or four inches in
breadth ; but it has often been found of more than
four times this size; and it has also been seen not
much  longer than an inch.  Its ordinary weight is be-
tween six and nine ounces; but it has varied in dif-
ferent subjects from eleven pounds to one  ounce.  It
is supposed, by many physiologists, that it frequent-
ly varies in size in the same individual.
   It is situated in the left hypochondriac region, in
contact with the  diaphragm,  below the eighth rib.
The position of the spleen  is  somewhat oblique,—
one extremity being directed downwards and rather
Forwards,  and the other  upwards and  backwards;
but when the stomach is distended, the lower end of
it is pushed  forward  by the great extremity of that
viscus.
   In general it is so deeply seated in the left  hypo1

  * In several cases where examination after death evinced that the pan-
creas had become enlarged and indurated,  particularly at the right ex*
tremitjr, die principal symptoms were jaundice,• great uneasiness after to*
ing food; vomiting some time after eating, but not immediately ,• extreme
acidity of the matter rejected.
    VOL. II.               19 
140
Enlargement of the Spleen
chondriac region, that it is out of view when the sub-
ject  is opened in the ordinary way : but in some
cases of enlargement, after the intermitting fever, it
has  extended downwards,  nearly as  low as  the
pelvis;  and towards the right side beyond the um-
bilicus.
   The external surface of the spleen is convex, in
conformity to the  surface of the diaphragm, with
which it is in contact.  The internal surface of  the
spleen is irregularly concave, having a longitudinal
fissure which divides it into two portions.
   The  spleen  is invested  by the  peritoneum,  one
process of which is  often extended  from the  dia-
phragm, above and behind it, in the form of ligament.
Another process of the  same membrane is extended
to it from the great extremity of the stomach.  The
peritoneum is also continued from, the spleen in the
form of omentum.
   Within this peritoneal covering is the proper coat
of the spleen, which is so closely connected to it, that
many anatomists have considered them as one mem-
brane :  they are, however, very distinct at the great
fissure, but the external coat is extremely thin.
   The  proper coat of the spleen is not very thick;
it is dense and firm,  and somewhat elastic, but not
much so.  It is partly transparent.
   The spleen has a large artery, which is one of the
three great branches of the cceliac. This vessel  runs
in an undulating manner  in a groove in the upper
edge of the pancreas, and in  this course sends off
 many small branches to  supply that  gland.   The
splenic artery, before it arrives at the spleen, divides
 into five or six branches, which  are also undulating
 in their progress, and penetrate into the body of the
 viscus at the above mentioned fissure.  These branches
 are distributed to every part of the viscus, and ram-
 ify  minutely. 
Vessels of the Spleen.
147
  From these branches, or from the main  trunk be-.
fore it ramifies, three or four smaller branches pro-
ceed to the left extremity of the stomach.  They are
called vasa brevia or arterise breves.
  The arteries which  enter the  spleen are accom-
panied by veins that emerge  from it,  and unite to
form a great trunk.   This trunk observes a course
corresponding to that of the splenic artery, and re-
ceives veins from the  stomach  and pancreas, which
correspond with the arterial branches  sent to those
organs.   The splenic vein  is one of  the  principal
branches of  the vena portarum.
  The splenic artery is very large  in  proportion to
the viscus to which it is sent, and the vein is unusu-
ally large in proportion to the  artery.  The vein is
also very tender and delicate in its structure.
  The absorbent vessels of the spleen are very nu-
merous.   It has  been  asserted,  that when those of
the external coat of the spleen are injected, they are
sufficient to  form a fine net-work on it. The absorb-
ents of the deep-seated parts unite to  the superficial
at the fissure where the blood vessels  enter.  They
terminate in the thoracic duct,  after passing through
several lymphatic glands.
  The  nerves of the spleen are derived  from the
solar plexus:  they form a plexus round the vessels
and accompany them through the viscus.
  The spleen consists of a substance which is much
softer than that of any other viscus of the abdomen.
This substance is made up either wholly or in great
part of the ramifications  of the splenic artery and
vein, which are demonstrated by injections to be very
minute and  numerous in this body.  There are  also
many fine white cords, like threads, which pass from
the internal surface  of the inner coat of  the spleen
into its soft substance, in which some of them ramify.
These cords connect the  substance of  the spleen 
148 Malpighi on the Structure of the Spleen.

pretty firmly to its coat,  and they seem to have the
effect of rendering the exterior part of the substance
more firm and dense than  the internal.   They are
particularly conspicuous if the spleen be  immersed
in water, and the coat pulled off while it is in that
situation.
   The spleen has a strong resemblance to the glan-
dular organs, but has no excretory duct, and its par-
ticular function is not very obvious : for these reasons
the structure of this organ is a subject of very inte-
resting inquiry.
   Malpighi,  who took* the lead in researches of this
nature,  before  injections of the blood vessels witb
wax were in  use, after investigating the structure of
the spleen by long  maceration,  by boiling, by infla-
tion, by the  injection of ink or coloured fluids* and
by examination with microscopes,  declared that its
structure was cellular ;  that 'the cells communicated
more freely with the veins  than the  arteries; and
that they might be considered as appendices of the
veins.   He  also asserted, that a  large number of
white bodies or vesicles were to be  found in those
cells and throughout the whole  substance  of  the
spleen, which were in bunches like grapes, and pre-
served their whitish  colour although the  vessels
around  them were injected with  a  coloured fluid.
This description of Malpighi appears to  have been
admitted by some of the very respectable anatomists
who were cotemporary with  him ; but it was most
 zealously opposed  by  Ruysch, who exhibited the
 spleen so completely injected with wax, that it ap-
 peared to be composed  entirely of vessels.*
    Ruysch  appears to  have paid great attention to

   * Two plates, taken from drawings of these preparations, are publkbed
 in Ruysch's works.  One is attached to Epistola Problematica Quarta, in
 the second volume ; and the other to Thesaurus Septimus, in the third
 volume. 
De La Sone on the Spleen.        149
this subject, and to have made many preparations of
the spleen.  From these he derived the opinion, that
the substance of this organ was entirely composed of
arteries,  veins,  absorbent  vessels  and nerves;  and
that if it were  properly injected before it was  dis-
sected, no other structure would be  found.    He
stated, that the  minute ramifications of the blood
vessels appeared to have acquired a peculiar quality,
and were so soft and delicate, that their texture was
destroyed  by the least friction ;  and  that  by the
slightest  degree of putrefaction  they  appeared to be
reduced  to a fluid state.  He also  denied the exist-
ence of cells, or of the whitish  bodies  described by
Malpighi.
   The question thus at  issue between these great
masters of their art, was very carefully examined by
M. De La Sone, a French physician, whose observa-
tions are published in the  Memoirs of the Academy
of Sciences for 1754.  After repeating the proces-
ses of each of these anatomists, and instituting some
others in addition, he adopted the opinion that there
was in the texture of the spleen  a pulpy substance
which was not a mere coagulum, but which, howev-
er, could not be injected.
   He derived his opiuion from this fact among others.
 After macerating the spleen a considerable time, and
 injecting water into the vessels until it returned co-
 lourless, he injected ink, and confined it some time in
 the vessels by  tying them: he  then  allowed the ink
 to flow out of  the vessels, and made various sections
 of the spleen, but no ink appeared in the pulpy sub-
 stance, although it was visible  in many small vessels
 which ramified in that substance.  He observes that
 this could not  have been the case, if the pulpy sub-
 stance had been composed entirely of vessels, as was
 supposed by Ruysch.
    He also examined the spleen after it had been in- 
150 Holler and the French Anatomists on the Spleen.

jected with wax, according to the manner of Ruysch,
and believed not only that the pulpy matter remain-
ed  uninjected, but that Ruysch himself, in  his own
preparations, removed this substance, supposing it to
exist  for the mere purpose of connecting the vessels
to each other.
  To see the blood vessels in the same state of dis-
tention in which they were  during  life, he  tied the
splenic vessels in a living animal, and  removed  the
spleen  with  the ligatures on the vessels.    In  this
situation he boiled  it, and  then  examined  the ap-
pearance of the vessels and  the pulpy substance.—
From these, as well  as  his other  observations,  he
decided, that the pulpy substance did not consist en-
tirely of vessels, but was  an  additional  and different
structure.
   He also suggested, that as the brain  and the mas-
cular fibres were so covered by blood vessels in the
injected preparations of Ruysch, that they appeared
to be composed entirely of vessels, when in fact they
consisted of a different substance, so the pulpy sub?
stance of the spleen was covered or obscured by the
blood vessels which passed through it, without con-
stituting its whole substance.
   He confirms the account of Malpighi respecting the
 Whitish Vesicles or Follicles ; anil  states, that in a
majority of cases they  are not to be  discovered with-
out a particular preparation ; but that they are gene-
rally  made obvious by long maceration of the spleen
in water4  In his opinion they are the  most essential
part of the organ.
   Notwithstanding these investigations of M. De La
Sone, the question  respecting  the  structure of the
spleen remains  not completely decided even to this
day.
   Haller,  who was perfectly well  acquainted with
the subject, inclined  to the  opinion of  Ruysch; 
        British Anatomists on the Spleen.     151

while Sabatier adopted completely the opinion of De
La Sone.
  It appears from the statement of Gavard, that De-
sault did not admit the existence of the transparent
bodies; although he believed that the pulpy substance
of the spleen, consisted of  cells which  resembled
those of the cavernous bodies of the penis.
  Boyer,  whose descriptions 6f the animal structure
appear to have been formed with  scrupulous exacti-
tude, admits the existence of  transparent  bodies;
sometimes  so  small as to be  scarcely  visible,  and
sometimes as large as the head of a pin.  He ob-
serves, that  the best method of examining them is to
place a very thin slice of the spleen between the eye
and  a strong light, when the transparency  of these
bodies occasions the slice of the spleen to appear as
if perforated.
   As to the general structure of the pulpy substance,
he avows himself unable to decide respecting  it; but
observes, that upon  examining  the cut surface of the
spleen, you perceive black liquid  blood flow from
the  vessels; if you then scrape this surface,  you may
express easily a species of sanies  different from that
 which flows from the vessels, which, after exposure,
 becomes red, and  resembles  coagulated blood ; whe-
 ther this is contained in the capillary vessels, or in
 the cavities of this organ, he  acknowledges himself
 unable to determine.
   Notwithstanding the sentiments  of these French
 gentlemen,  many of the British Anatomists, who are
 entitled to great attention on account of their skill in
 minute injections, have adopted the ideas of Ruysch.
 Among these  are to be  mentioned the late  Dr. F;
 Nicholls, and  many of the anatomists of London, as
 well as the second Professor Monro, of Edinburgh.
 There are, however, two remarkable exceptions to
 this account  of  the British anatomists.  The late 
 152     British Anatomists on the Spleen.

 Mr. Falconar, who wrote a dissertation on the situa-
 tion and structure of the spleen, which contains the
 sentiments of the late truly respectable Mr. Hewson,*
 after stating that  the organ was extremely vascular,
 so that when injected it appeared like a mere conge-
 ries of vessels, makes this unequivocal  assertion—,
 that there are innumerable cells dispersed through-
 out the whole substance of it, which are so small that
 they are only to be discovered by the aid of a micro-
 scope ; and are to be seen after steeping a thin piece
 of spleen, the blood vessels of which have been mi-
 nutely injected, in clear water during  a  day, and
 changing the  water frequently.  He also adds,  that
 the ultimate branches of the arteries and veins form it
 beautiful net-work on each  cell; and that these cells
 are sufficiently distinguished from the irregular inter-
 stices of the cellular substance, by their round figure
 and their great regularity.
   Mr. Everard Home, in his  papers on the structure
 and uses of the spleen, confirms the  account of the ve-
 sicles in this organ; and adds that  these vesicles arrt
 occasionally seen in a distended and in a contracted!
 state.   That when distended they are twice as large
 as when contracted, and are  distinguishable by the
 naked  eye; whereas, when contracted, they require
 a magnifying glass to be distinctly  seen.  These ob-
 servations appear,  to  have been made upon quadru-
peds, f
  Professor Soemmering appears to unite in the gc*
 neral sentiment of the  British anatomists, that the
spleen is simply vascular.   He says, that the tuber-
culi which sometimes appear  in it, when examined
with a magnifying glass  appear to  be composed en-
tirely of vessels.
 See Experimental Inquiries, vol. iii.
t See the London Philosophical Transactions for 180« 
 Questions relating to the Structure of the Spleen. 153

   There are therefore two questions not perfectly de-
 cided respecting the spleen.
   First. Whether its general structure is simply vas-
 cular, or whether there is any other structure either
 cellular or more substantial, which  composes its ge-
 neral bulk.
   Second. Whether the small transparent vesicles,
 originally described by Malpighi, are to be regarded
 as essential parts of the structure of the spleen.
   With respect to the first question, the injections of
 Ruysch, and of the British Anatomists  in general,
 and even of  Mr. Hewson,  as  well  as of Haller and
 Soemmering, seem to afford bositive facts in opposi-
 tion to  those of a negative kind adduced by M. De
 La Sone, and render it highly probable that the ge-
 neral structure is simply  vascular.
   But the second question stands on different grounds.
 The existence of small transparent vesicles, although
 denied  by Ruysch, and neglected by the British Ana-
 tomists  in general, was asserted as a positive fact by
 Malpighi and De La Sone; and their assertions have
 been confirmed, not only by most of the French Ana-
 tomists, but  also  by  Hewson  and Home among the
 British.
   The sentiments of physiologists respecting the func-
 tions of the spleen, are more discordant than those of
 anatomists respecting its structure; although the sub-
ject has been considered by many authors of great in-
genuity.*

        * See M. Lieutaud. Element* Physiologic.
        Hewson's Experimental Inquiries, vol. iii.
        Dr Rush. Medical Museum, vol. iii.
        Haller. Eleracnta Physiologic, torn. vi. page 414,
Vol. ii. 
CHAPTER IV.
  OF THE URINARY ORGANS AND THE GLANDULJE
                    RENALES.

  The urinary organs consist of the Kidneys, which
are situated in the lumbar regions;  of the Bladder,
which  is  in the pelvis; of the Ureters, which  are
flexible tubes or canals that pass from the kidneys to
the bladder; and of the Urethra, or tube through
which the urine is discharged from the bladder.
  These organs have but  little connexion with the
peritoneum.  The kidneys are behind it; and a con-
siderable  quantity of cellular  membrane is  placed
between them and it.  The ureters are also behind it;
and but a part of the bladder is invested with it.
  The Glandulse Benales are described with the uri-
nary organs, on account of their contiguity to the kid-
neys : and to avoid a derangement of the natural or-
der of description they are considered  first.
  The urethra pertains to  the organs of generation
as well as to the urinary organs, and can be descri-
bed most advantageously with them.

                    SECTION I.

            Of the Glandulse Benales.

  These are two small bodies, situated on the psoas
muscles, one on each side of the  spine, behind the
peritoneum and above the kidney, being in contact
with its upper and anterior edge. They have an ir-
regular  semilunar  figure with three sides, one of 
             The Kidneys and Ureters.         155

which is accommodated to the convexity of the kid-
ney.  Their colour is commonly a dull yellow.
  The appearance and texture of these bodies have
some resemblance to those of glands, and hence their
name, but they have no excretory duct.
  When they are laid open by an  incision, a cavity
often  appears, which is somewhat triangular, and
from the lower part of it a small thin ridge arises.*
  A small quantity of fluid is generally found in it,
which  has a very dark colour in adults, is yellowish
in young subjects, and red in infants.
  These bodies have not a single artery appropriated
to them, as the spleen has, but receive small branches
from several contiguous sources ; viz. from the arte-
ries of the diaphragm, from the coeliac  artery or the
aorta, and from the arteries of the kidneys.   There
is generally one  principal  vein,  as well  as some
that are smaller, belonging  to each of these  bodies:
the large vein on the right side generally opens into
the vena cava, and on the left into the  left emulgent
vein.
   These bodies were first described by Eustachius,
and have been regarded with attention  by many ana-
tomists since that period.  They exist in a great num-
ber of animals;  but their  nature  and  functions are
altogether unknown.

                     SECTION II.

           Of the Kidneys and Ureters.

   The kidneys are two glandular bodies  which se-
crete the urine.   They are of a dull red colour, and
 their form has a strong resemblance to that of the
 bean which  bears  their name.  They have a pecu-
  * The cavity in these bodies has sometimes been sought for in vain.
jfaller found it in sixteen cases out of nineteen- 
liti
The Kidneys.
liar texture, which  is uniform, and  not  granulated
or composed of acini; and they are covered by a thia
delicate tunic, which has no connexion with the pe-
ritoneum.
  They are situated in the lumbar regions of the ab-
domen, one on each side of the spine.   They are
opposite  to the two last dorsal and the two first  lum-
bar vertebrae.  They rest principally upon the psoas
and quadratus  lumborura musdes, and  their posi-
tion is oblique ; the concave  edge presenting inwards
and forwards, the convex edge backwards, and the
upper extremity approaching nearer to the spine than
the lower.
  The Bight Kidney is  situated rather  lower  than
the left:  it is below the posterior part of the right
lobe of the liver, and  behind the  duodenum and the
colon.  The  Lift Kidney is below the spleen, and
behind the descending portion of the .colon.   Each
of the kidneys is below and very near to  one of the
glandular renales.
  They are surrounded  with a large  quantity of lax
adipose membrane, which in corpulent persons forms
a very large  mass of adeps  around them ;  while  in
the emaciated they are surrounded with a membrane
almost free from fat.   Each kidney has  two broad
sides, two extremities, and two edges.  The side  or
surface which is posterior, when the  kidney is in  its
natural situation, is rather  broader than  the other.
The upper extremity, or  portion,  is also broader
and larger than the lower.   The  edge  which is pos-
terior and external is regularly  convex  ; the anterior
edge is concave; but  the concave edge, or margin,
is not very regular.  In  the middle it  is  largely in-
dented ;  in this indentation is a deep fissure, which
separates the two broad surfaces or sides  of  the
gland from each other; and here the breadth of the
posterior surface is evidently greater than the anterior. 
                  The Kidneys.               157

  Each of the kidneys receives a large artery, which
proceeds immediately  from the aorta, nearly in a
rectangular direction.  A vein, which opens into the
vena cava,  accompanies the  artery.   It is obvious,
from the situation of the kidneys with respect to the
great vessels, that the artery  on the right side must
be longer than that on the left, and that the reverse
of this must be the case with  the veins; the veins are
also anterior to the arteries. At the great fissure these
vessels divide into several branches, which enter the
kidney at that place.   The branches  of the vein are
before and  above;  those of the artery  are below, and
in the middle.   Surrounded  more  or  less  by the
branches of those  vessels, is  a membranous sac, the
breadth of which  extends from above downwards.
This sac terminates in a tube that proceeds from the
lower part of the fissure down  to the  bladder.  The
sac is denominated the pelvis of the kidney, and the
tube a ureter: each of these parts will soon be more
particularly described.
  The substance of the kidney, as has been already
said, is uniform in its texture, and of a reddish brown
colour.   When  it  is  divided  by an  incision made
lengthways, and from its convex to its concave edge,
there appears to be a small difference  in the different
parts of it.   The exterior part, which is called corti-
cal, is rather more  pale in colour and softer in  con-
sistence than the internal part.  It varies in thickness,
so that some writers have described it as equal to two
lines, and others to one-third of the  kidney.  In a
majority of subjects it will be found between the two
statements.
  The interior part is called medullary, or tubular,
and  appears  to be  composed of very fine  tubes.
These tubes are so arranged,  that a  number of pa-
pillae or cones are  formed by their convergence, and
project into the fissure of the kidney.  These pa- 
158               The Kidneys.
pillse have been  supposed to consist of a substance
different from either of the two  above mentioned,
but they appear to be formed merely by the tubular
part.
  The arteries, accompanied by corresponding veins,
and by nerves and absorbent vessels, after ramifying
in the'fissure of the kidney, proceed into its substance,
and continue their aborescent ramifications until they
have arrived very near the exterior surface.  They
are so uniformly distributed to the different parts of
the organ, that when the blood vessels are injected
with wax, and the substance of the kidney is removed
from the injected matter, as  is the case in corroded
preparations,  the injection exhibits accurately the
form of the kidney.
  The  large branches of the  blood vessels occupy
the vacuities between  the papillae in the fissure of
the kidney.  When they penetrate the substance of
the kidney, they are enclosed by  sheaths which are
derived  from the coat of the gland, and  are  sur-
rounded by  membrane,  which frequently contains
adeps.
  There are commonly ten or twelve papillse in the
fissure of each kidney, but there are sometimes more
and  sometimes less  than this  number.   These pa-
pillae are surrounded by a membranous sac of a cor<
responding form ; the papilla  being a cone, and the
sac resembling the upper part of a funnel.   The
sac is  therefore called an infundibulum,  or calyx*
Sometimes there  are two papillae in each infundibu-
lum, and then the form of the sac is not so regular.
The infundibulum adheres to the base of the papilla,
but lies loose about  the other parts of it.   Each in-
fundibulum communicates, at its apex, with the pel-
vis of the kidney.
  The Pelvis, as has  been already mentioned, is a
membranous sac which terminates  in the ureter, ex* 
Cortical and Tubular Portio7is of the Kidney. 159

terior to the kidney.   This sac generally divides it-
self, in the fissure of the kidney,  into three large ir-
regular branches, each of which very soon terminates
in three or four of  the infundibula above described.
That portion of the sac which terminates in the ure-
ter is exterior to  the kidney.
   When the interior parts of the  kidney are exposed
to view, by the section  above mentioned, after the
arteries and veins have been  minutely injected, the
cortical part will  be found to consist almost entirely
of the minute ramifications of these vessels.   Among
them are some small  bodies,  which  are dispersed
through the substance, like berries on a bush: these
are asserted also to be composed  of vessels.
   The tubular part certainly proceeds from this vas-
eular cortical substance :  for Ruysch,  and after him
several  other injectors, have filled these tubes with
injection thrown  into the arteries.
   The tubuli,  of which this part is composed, seem
to arise obscurely from the  cortical part.  They soon
assume somewhat, of a radiated  direction, and are
finally arranged so as  to form the papillae or cones
above  described.
   On  these papillae  or cones some of them can  be
traced, uniting with each other, to form larger tubes,
which terminate  on the surfaces of the papillae, in
orifices  large  enough to be seen distinctly.   From
these orifices urine may be forced out  by compress-
ing the papillae.  On this account the tubes have been
called  tubuli uriniferi.
   In the foetal state the kidney is formed  of a num-
ber of distinct lobuli,  each of  which consists of a
papillae  with the  cortical  matter connected to  its
base.   Soon after birth these lobuli  coalesce; and
in two or three  years the  substance of the  kidney
appears uniform, as above  described.   In some ani-
mals this lobulated  structure  continues  during life  ; 
160 Nerves and Lymphatics.—Coat of the Kidney.

in them, and also  in  the foetus,  each  lobe appears
like a distinct organ.   Although  in the adult kidney
this structure has disappeared, the papillae and the
tubular part connected with them are somewhat de-
tached from each other, in a manner corresponding
to their original arrangement.
   The Nerves of the Kidneys originate from the se-
milunar ganglion,  formerly mentioned.   They form
a plexus round the blood vessels, and go with them
into the gland.
   The kidneys have internal and external absorbent
vessels, although the external  vessels are very small.
These absorbents pass through glands  in the lum-
bar region to the thoracic duct.
   The proper coat  of the kidney is said, by some
anatomists, to consist of two lamina; but this can-
not be shown  in common  cases.   It appears simple
in its structure,  and  very flexible.  It is but slightly
connected  to  the  glandular substance which it en-
closes, and may  be easily peeled off.  It is reflected
inwards  at the  fissure of the kicjney,  and can be
traced inwardly to some distance, forming sheaths
for the vessels.  In this  internal  situation it is very
thin.
                  The Ureters.

  The pelvis of the  kidney terminates exteriorly in
the Ureter, which  is a membranous cylindrical tube,
rather flattened, and between three and five lines in
diameter, with some  variations in this respect.
  The Ureters descend from the pelvis of the kid-
ney so as to pass obliquely across the psoas muscle
and the  great iliac  vessels.   They are  behind the
peritoneum, but in contact with it.   They approach
the pelvis near the junction of the os ilium with the
sacrum, and thence descend forwards and inwards,
surrounded with loose  cdlular membrane, to the 
            Structure of the Ureters.          161

lower part of the bladder, into which they are in-
serted at its external and posterior part.  They first
penetrate obliquely the muscular coat, and then pro-
ceed between the muscular and  internal coats, from
half an inch to an inch, in an oblique direction, from
without inwards and forwards, when they terminate
by small orifices in the internal  coat, each of which
is at an  equal distance, (rather more than an inch,)
from the orifice of the urethra, thus forming a triangle
with it.
  The ureters are said to have three coats.  The ex-
terior appear to be derived  from the  cellular sub-
stance :  within it is another, which has been regarded
very differently by different anatomists  ; some consi-
dering it as merely membranous, and others as mus-
cular.   If the ureter be laid open and the internal
coat peeled off,  the muscular structure of this coat is
often very perceptible.
  The  internal coat  is called villous, or mucous, and
is continued from  the internal  coat of the bladder.
Over this eoat  mucous is  constantly spread,  which
defends it from the acrimony of the  urine.   It is
very difficult to separate the two last mentioned coats
from each other.
  The  ureters receive blood vessels and nerves from
those of the neighbouring parts.   Their  internal
coat is  very vascular, and is also very sensible of ir-
ritation.  The  passage of a  small  urinary  calculus
can be  traced from  the  pelvis of the kidney to the
bladder, by the exquisite pain and the  spasmodic af-
fections which it often excites.
Vol. n.
21 
162
Situation of the Bladder.
                   SECTION 111.

             Of the Urinary Bladder.

  The urinary bladder is a large sac, of a muscular
and membranous structure, which occupies the ante-
rior part of the  cavity of the  pelvis, immediately
within the ossa pubis.
  The size of the bladder is in  a continued state of
variation, according to the quantity of urine secreted.
When moderately distended, it  is  of an irregular
oval form, but rather more flat at its lower extremity
than above.  It varies in form according to  the dif-
ferent circumstances of the pelvis to which it has been
subjected.
  It  is fixed firmly and immoveably to the pelvis
immediately  within the symphysis pubis ; so that it
is always  to be found  there  of a larger or smaller
size.  This fixture is produced by the attachment of
the  lower portion of  fundus of the  bladder to the
parts beneath it, but principally by the anterior liga-
ments of the bladder which proceed one on each side
from the lateral surfaces of the prostate gland, and are
inserted into the  pubis of the corresponding side at
the lower part of the  symphysis.  These ligaments
are in fact the  extension of  a membrane,  (called by
the French Anatomists, the pelvic aponeurosis,) which
proceeds  from  the  upper  part of the pelvis to the
side of the prostate gland and  bladder, and which
may be seen by turning off the peritoneum from the
levator ani  muscle.*    It is sometimes completely
empty, and occupies no more space than the thickness

  * See Thesis on Femoral Hernia, &c.  by Gilbert Breschet. Paris, April,
1819. Colles' Surgical Anatomy, Dublin, 1811, for a more minute account
of this membrane. Ed. 
Situation of the Bladder.          163
of its coats requires.  When moderately distended,
it  occupies  a  considerable  portion  of the pelvis:
when distention increases, it presses  the parts poste-
rior to it against the sacrum, and extends itself above
the brim of the pelvis into the general cavity, rising
not only to the umbilicus, but in some cases to the
epigastric region.
   In males the relative situation of the bladder and
rectum is such, that the  upper and  middle part  of
the rectum  is behind  the  bladder;  but the  lower
part of the  rectum,  following the curve of the  os
sacrum and  coccygis,  is  below the posterior part of
the bladder.
   In females the vagina and uterus are situated be-
tween the bladder and rectum ;  so that the connex-
ion of these last mentioned parts is very different  in
the two sexes.
   The peritoneum is reflected at the anterior part of
the brim of the pelvis from the  abdominal  muscles,
which it lines, to the upper part  of the  bladder,
which is  generally contiguous to the brim of the pel-
vis.   It continues  over to the posterior  side of the
bladder,  and passes down upon it some distance  to-
wards the lower part; but before  it  has arrived  at
the bottom, it is reflected towards  the sacrum.
   In males it extends from the bladder to the rectum,
and in females to the vagina and uterus; so that there
is  a considerable  portion of the lower part of the
bladder which is not invested by the peritoneum.  It
also follows  that when the bladder  is extended  into
the abdomen, and  rises above the brim of the pelvis,
that part of it which presents anteriorly, and is  in
contact with the abdominal muscles,  is without a co-
vering of peritoneum, being below it.
   The bladder is  composed of  a  coat consisting  of
muscular  fibres, of a stratum of cellular substance
immediately within this, and of an  internal  lining 
164      Muscular Coat of the Bladder.

membrane, which has been called villous, but, as
there are  no villi  perceptible on  it, may be more
properly denominated mucous.
  It should be observed, that,  in  addition to these
coats, the  bladder has a peculiar investment of the
peritoneum,  as has been  already described;  and
also  of  the  common cellular  membrane, which  is
placed between it and every part to which it is con-
tiguous.
  The Muscular Coat  of the  Bladder  consists  of
fibres which are not spread over it of a uniform thick-
ness, but are thin in some places,  and  in  others are
collected in fasciculi.  They run in every direction:
some appear longitudinal, others circular, and some
oblique ;  and  there  are interstices between  them
which are occupied  by cellular  membrane.  The
longitudinal fibres originate from  the  lower part of
the bladder;  and as this  is the  fixed part of that
viscus, it is the place from which these fibres must
necessarily act. These fibres are generally exterior.
There is no arrangement of muscular fibres to which
the term of sphincter can properly be applied ; but
many anatomists  have thought  that the  fibres near
the neck of the bladder, by their separate contrac-
tion, might prevent the  escape of urine ; this senti-
ment, however,  is contrary to  that of several very
respectable writers.
   The direction of the fibres,  taken collectively, is
such, that, when they all contract, the cavity of the
bladder is completely obliterated.
   The cellular substance between  the  muscular and
 internal  coats is dense.   It  yields in a  remarkable
 manner to distension, and recovers its original dimen-
 sions very easily.   From its  analogy to a similar
 coat in the intestines, it is called the Nervous  Coat.
   The Internal Coat of the bladder is of a light co-
 lour in the dead subject, when  it has been free from 
Internal Coat of the Bladder.        165
disease.  It had been called villous improperly;  for
the villous structure is not apparent upon its surface.
Being continued from  the integuments of the  body
which are extended along the urethra, it has been in-
ferred, that the surface of this coat was formed by the
epidermis; and some respectable authors have sup-
posed that  they had seen cases  in which portions of
the epidermis of the bladder had separated and been
discharged; but these appearances are very equivo-
cal, and it  is by no means certain that an epidermis
exists there.*
  The fasciculi of fibres of the moscular coat occasion
this coat to appear very irregular, but these irregula-
rities correspond exactly with the arrangement of the
fibres of the muscular coat.
   When the internal eoat is separated by dissection
from the  muscular, its  surface is very smooth and
uniform.   In the  recent subject, when no disease
has previously existed, it is always spread over with
mucous of  a 'light colour,  but nearly transparent,
which can  be easily  scraped off.   This mucous is
spread upon the surface so  uniformly,  that it must
be derived from sources which  are  situated upon
every part of the surface; but these sources are not
very obvious.  On the membrane of the  nose the
orifices of many  mucous ducts  are very visible,  but
such orifices  are not to be seen on  this surface.—
Haller mentions  that   he  has  seen mucous  glands
near the neck of the bladder; and it is stated by the
pupils  of  Desault,  that, in  one of  his  courses,  he
pointed out a number of these  glands, in a subject
 who had been afflicted with  a catarrhal affection of
the bladder.

  * In the fauces and the follicles of the tonsils an effusion of coagulable
matter, in consequence of inflammation, often forms crusts,  that may be
mistaken for sloughs of the integuments, although those integuments re-
main entire. 
166          Mucous of the Bladder.
   Notwithstanding  that  the  sources of this mucou9
are obscure, the quantity of it is sometimes immense.
In some cases, where the secretion is increased by
the irritation of a calculus in the bladder, the urine
is rendered somewhat viscid and white coloured by
the mucous mixed with it; which, after the urine has
been allowed  to  remain  for some time, subsides in
such quantities  as demonstrates  that  many ounces
must  be secreted in the course of the twenty-four
hours.  The same circumstances occur, without the
irritation of calculus, in the disease called catarrhus
vesicae.*
   It is probable that, in healthy persons, a great deal
of it passes off unperceived,  being dissolved or dif-
fused in the urine.   From the quantity and the regu-
lar diffusion of this mucous on  the  surface  of the
bladder, there is the greatest  reason for believing
that is is effused from every part of the surface; and
it is a question that  has not been decided whether it
is discharged from glandular  ducts too small  to be
perceived, or from  the exhalent extremities of the
blood vessels.   It is probable that the use of it is to
defend the internal coat of the bladder from  the acri-
mony of the urine.
  The symptoms of  a stone in the bladder, as well as
of several other diseases, evince that this  coat is en-
dued with a great degree of sensibility.
  It is evident that  the essential parts in the general
structure of the bladder  are  the muscular coat and
the internal coat last described: but in addition to
the account of them, there are some other important
circumstances to be  noted in  the description of this
organ,  It has been already stated, that the  form of
the bladder was  an  irregular oval, although it was
  * In some cases this mucous soon becomes putrid, and during the putre-
factive process deposits a substance which appears to be calcareous. 
Orifice of the Urethra.           167
somewhat varied in different persons.  The oval form
is not much altered at the part called the neck of the
bladder, where the urethra passes off from it.   The
orifice of the urethra is situated anteriority at the low-
ermost part of the bladder.   On the lower surface of
the urethra, at its commencement, and on the bottom
of  the   bladder,  immediately connected  with  the
urethra, is situated the  Prostate Gland, (to be here-
after described with the organs of generation,) which
is a firm body, that  adheres strongly both to  the
bladder and urethra.   This circumstance gives par-
ticular firmness and solidity to that part of the blad-
der.   It has also been  observed, that the bladder is
attached firmly to the ossa pubis, at  its neck, about
the origin  of the urethra.   Each  of these circum-
stances have an effect upon the orifice of the urethra;
and when the bladder is opened, and this orifice is
examined from within, it appears to be kept open by
the connexion of the bladder with  the prostate, and
has been very  justly  compared to  the opening of
the neck of a bottle into the great cavity of that
vessel.*
   The orifices of the two ureters are at equal dis-
tances from the orifice  of the urethra, and form  with
it the angles of a triangle.  That part of the internal
surface of the bladder which is within  this triangu-
lar space, is more smooth  than the  remainder of the
 same surface, probably in  consequence of the adhe-
sion of the bladder to the prostate, and to other parts
 exterior to it.

   * The late Mr. Lieutaud, and after him the trench anatomists of the
 present day, have described a small tubercle at the lower and posterior
 part of the orifice of the urethra, which resembles the uvula in form.  It
 has not been noticed here; and M. Boyer states, that it is often scarcely
 perceptible.  He, however, makes a remark which is very worthy of at-
 tention, viz. that it is very subject to enlargement in old people, forming a
 tumour which impedes the discbarge of urine.  Sabatier has also made the
  same observation. 
168  Ligaments and Vessels of the Bladder.

  That part of the bottom of the bladder which is
immediately behind  the triangular space, is rather
lower than this space; and but a small portion of eel-
lular membrane exists between it and the rectum in
males, and the vagina in females.
  The upper part of the bladder is  connected with
the umbilicus  by means of a ligament, which passes
between the peritoneum and the abdominal muscles.
This ligament consists of three cords.  One of these,
which is in the middle, arises from the  coats of the
bladder, and was, in the foetus, the duct called ura-
chus:  the other two,  which are connected  to the
bladder principally by cellular membrane, were ori-
ginally the umbilical arteries.*  The middle cord is
of a light colour and fibrous structure;  it is thickest
at the bladder,  and gradually diminishes as it ap-
proaches  the umbilicus.  In a few instances it has
been found to be hollow.  In its progress to the umbi-
licus it becomes more or less blended with the linea
alba or the tendons of  the abdominal  muscles.   The
other cords are generally solid.   After passing from
the umbilicus to the  bladder, they continue on the
sides of that viscus, and finally terminate at the hy-
pogastric or internal iliac artery.
  In the very young subject these cords are invested
by distinct  processes of the peritoneum, but their
position is exterior to the peritoneum.
  As the bladder  is situated very near most of the
large  ramifications of the hypogastric artery in the
pelvis,  it  receives branches from several of them;
viz. from the umbilical arteries before  they termi-
nate ;  from the pubic; from the obturators, &c. These
branches  ramify in the  cellular membrane  exterior
to the muscular  coat, and also in the cellular sub-
stance between the muscular and internal coats.  It
  ** See the accounts of these parts in  the description of the Abdomen of
the Foetus 
General Observations.            169
has been conjectured, that their terminations  in ex-
halents on the surface of the bladder are remarkably
numerous.
   The veins correspond with  the arteries, but they
are very numerous on the lower and lateral parts  of
the bladder,  and  by uniting with the veins of the
rectum form a remarkable plexus.
   The Lymphatic Vessels of this organ do not appear
more numerous than those of other parts.  They pass
on each side the bladder  in  the course of its blood
vessels,  and unite with  the larger lymphatics, and
the glands which lie upon the  great blood vessels on
the sides of the pelvis.
  The Nerves of the bladder are  derived both from
the intercostal nerve and from the nerves of the me-
dulla spinalis, which  pass off  through the sacrum ;
and therefore the bladder is more affected  than the
viscera of  the abdomen,  by injuries of the  medulla
spinalis.


    The action of the muscular fibres of the bladder in ex-
      pelling urine, and the effect of those fibres which are
      situated near the orifice of the urethra in retaining it,
      can be considered with more advantage after the struc-
      ture of the urethra and the  muscles  connected with
      that canal have been described.
        It has been stated, that the internal coat of the blad-
      der is very sensible j but it may be  added, that in
      consequence of disease about the neck of the bladder,
      the natural sensibility appears most inordinately in-
      creased.   When the intensity of pain which accom-
      panies these complaints, the  frequent recurrence of
      paroxysms, and their  duration, are taken into view,
      there seems reason to believe that none of the painful
      affections of the human race exceed those which arise
      from certain diseases of the  bladder   Happily these
      diseases are not very common.
        The functions of the kidneys is to secret urine,and
      that of the bladder to retain it, until the proper time
      for evacuation.
  Vol. ii.                22 
170            General Observations.
  The urine may be regarded  as  an excrementitious
fluid, which contains many substances in solution that
are constantly found in it, and many others that are
occasionally in it, which are taken as aliment or me-
dicine,  and pass to the bladder with little, if any,
change.  The odour of the rose  leaf,  the colour of
rhubarb, &c. are occasionally perceived in urine.
  The substances constantly found in urine are nume-
rous.   The chemical account of the subject is so long,
that it cannot be detailed here; but the student ought
to make himself acquainted with it,  and he will read
with  great advantage  Johnson's  History  of Animal
Chemistry, vol. 2d, page 363 j and also Thompson's
Elements of Chemistry, page 333. 
CHAPTER V.
      OF THE MALE ORGANS OF GENERATION.


   These organs consist, 1st, of the  Testicles, and
their appendages.
   2d. Of certain parts denominated the  Vesiculx
Seminales and the Prostate Gland, which are situ-
ated near the commencement of the urethra, and are
subservient to the purposes of generation.
   3d. Of the Penis.

                    SECTION I.

      Of the Testicles and their Appendages.

   The  Testicles  are two  bodies of a flattened oval
form.  Each of them has a protuberance on its upper
and posterior part called Epididymis, and is connect-
ed to parts within the  cavity of  the abdomen by a
thick cord, which proceeds to it through the abdo-
minal ring.   Each testicle also appears to be contain-
ed in a sac, which is suspended by this cord and co-
vered by the  common integuments.
   That portion of the common integuments  which
forms the external covering of the testicles, is deno-
minated
                  The Scrotum.

   The skin of the scrotum, although it is very often
in a state of corrugation, has the same  structure with
that  on  other  parts of the body,  except that it is 
172         Structure of the Scrotum.

rather thiner and more delicate.  The superior deli-
cacy of this portion of the skin is evinced by the great
irritation produced by the application of stimulating
substances, and the desquamation of the cuticle, which
seems to be the effect of irritation.  There are many
sebaceous follicles in this portion of skin ; and after
puberty there are  often a few long hairs growing out
of it, the bulbs of which are often very conspicuous.
There is a  small  raised line in  the middle of this
skin, which commences at the root of the penis, and
proceeds backwards, dividing it into two equal parts:
this  line is denominated  Baphe*
   The corrugation which  so often takes place in the
skin of the scrotum, appears to be occasioned by the
contraction of certain  fibres, which are in the cellu-
lar substance immediately within it.   This  cellular
substance appears  to be  attached in a particular way
to the  skin ;  and it also invests each testicle  in such
a manner, that when they are  withdrawn a cavity is
left in it. It has long been observed,  that no adipose
matter is found in this cellular substance ; but it is
often  distended with water in  hydropic  diseases.
As the contraction and corrugation  of the  scrotum
has been imputed  to this substance,  it has been  ex-
amined with particular  attention by  anatomists,  and
very different sentiments have been entertained re-
specting it.   While some dissectors have  asserted
that muscular fibres could be seen in it, which they
have denominated the Dartos  Muscle; others have
said that this substance was  simply  cellular,  and
without any muscular fibres.  This difference of sen-
timent may possibly have arisen  from the different
conditions  of this  part  in different  subjects ; for in
some cases there are appearances which seem to jus-
tify  the assertion that muscular fibres  exist in  this
structure.
   After the testicles are removed, so as to leave the 
Action of the Dartos Muscle.        173
cellular substance connected with the skin, if the scro-
tum be inverted,  and this substance examined in a
strong light, many fibres will appear superadded to
the common cellular structure ; and  sometimes their
colour can be distinguished to be red.  It is not as-
serted that this will be uniformly the case; but cer-
tainly it has often been observed in this way.
  The existence of an organ  which  possesses  the
power of contraction, within the skin of the scrotum
and connected to it, is evinced by  the corrugation
which takes place when the scrotum is suddenly ex-
posed to cold, after  having been very warm.  This
corrugation occurs in a very sudden  and  rapid man-
ner, in some cases, in which  the  wounded  scrotum
is thus exposed for the purpose of dressing :  for ex-
ample, upon  removing an  emollient poultice from
this part some days after the operation for the cure
of hydrops testis,  by incision, if the air of the cham-
ber be cool, a motion of the scrotum will take place,
almost equal to the peristaltic  movements Of the in-
testines.                                        C
   The Arteries of the scrotum are derived from two
sources.  One or two small arteries, which arise from
the femoral artery, between Poupart's ligament and
the origin of the profunda, are spent upon it.  These
are called the external pudic arteries.  It also re-
ceives some small branches from the internal pudic
artery.
   The Nerves of the scrotum are principally derived
from the  lumbar nerves.

               The Spermatic Cord.
   The cord which proceeds to the  testicle through
 the abdominal ring, appears at first  view like a bun-
 dle of muscular fibres;  but it consists of an  artery
 and veins, with many lymphatic vessels and nerves,
 and also the excretory duct of the testicle, connected 
174 Cremaster Muscle.—Bloodvessels of the Testicle.

to each other by cellular substance, and covered by
an  expansion of muscular fibres which are derived
from the lower edge of the internal oblique muscle of
the abdomen, and continue from it to the upper part
of the testicle.   These fibres constitute the Cremas-
ter Muscle.
   The artery above mentioned is called the Sperma-
tic.  It commonly arises from the front of the aorta,
very near its fellow, at  a small  distance below the
emulgents:  and is not much  larger than  a crow's
quill.   It  proceeds downwards behind the  perito-
neum and  before  the psoas  muscle and  ureter.—
While it is in contact with the psoas muscle,  it joins
the ramifications of the vein.   It afterwards meets
the vas deferens, and proceeds through the abdomi-
nal ring to the back  part of the testis.    Before it ar-
rives  at the testis it divides into several  branches,
two of which generally go to the epididymis, and the
others penetrate the tunica albuginea  on the upper
and back of the testicle, and ramify very minutely
on the fine membranous partitions which exist in that
body.
   In addition to the spermatic artery, there is a small
twig from the umbilical  branch of the hypogastric,
which passes to the spermatic cord along the vas de-
ferens.
  The branches of the spermatic vein are much larg-
er than those of the  artery:  several of  them proceed
from the testicle so as to correspond with the  arterial
branches; and in addition to  these there  are many
smaller, which also arise  from  the testicle and epidi-
dymis.   In their course up the cord   they  ramify,
and again unite, so as to form  a considerable  plexus,
which is called the  Corpus Pampiniforme, and con-
stitutes a considerable part of the volume of the sper-
matic cord.
   As they proceed  upwards  they unite into a few 
Lymphatics and Nerves of the Spermatic Cord.  175

larger veins ; and finally, on the psoas muscle, they
generally form one trunk, which continues  upwards
so as to unite with the vena cava on the right side,
and the emulgent vein on the left.
  Sometimes, but not often, there are several sper-
matic veins on each side.
  The Lymphatic Vessels of the testicle are very nu-
merous, considering the size of the organ.   Six or
eight, and sometimes more, large trunks have been
injected,  running upon the cord, and continuing to
the glands on the back part of the abdomen.
  The Nerves of the testicle are derived from those
which supply the viscera of the abdomen, and are to
be found in the cord although  they can scarcely be
traced to the testicle.  A small plexus, called  the
spermatic,  is formed by fibres from the renal plexus
and from the sympathetic  nerve.  These fibres ac-
company the  spermatic vessels, and in all probability
enter the body of the testis and the epididymis.  The
spermatic cord and cremaster muscle receive filaments
from the second lumbar nerve.
  In addition to  these vessels, the  Vas Deferens,
which is much firmer than  either of  them,  is always
to be distinguished in the back part of the  cord.
  They are all covered in front and  on  the sides by
the cremaster muscle, which passes with them from
the lower margin of the internal oblique, through the
abdominal  ring, and continues to the upper part of
the external  coat of the testicle, which is a sac appa-
rently containing that organ, and upon this sac it is
spread out and terminates.
              The Tunica Vaginalis.

   The External Coat of the testicle, which  is  com-
 monly called the  Tunica Vaginalis, is a  complete
sac which  encloses the testicle as the  pericariduin
encloses the heart.  It covers the body of the testicle 
176            Coats of the Testicle.

and epididymis, and adheres closely to them.   It is
then reflected from them so as to form a loose sac,
which appears to contain them.   The  cavity of the
tunica vaginalis commonly extends above the booj of
the testis up the cord, and is oval or py^riform.--This
sac is so reflected from the body  of the testicle tha
there is  a place on the upper and back part of that
body, at which the  blood  vessels enter it, without
penetrating the sac.
   It resembles the peritoneum and other serous mem-
branes in texture, and is therefore thin and delicate.
It always contains a quantity of moisture, sufficient to
lubricate the surface which it forms.
   When the tunica vaginalis is lain open, the testicle
appears as if it were contained in the posterior part
of its cavity.                            ,      -
   The testicles, as has been already stated, are of a
flattened  oval form.  Their  position  is somewhat
oblique, so that their upper extremities look upwards
and  forwards,  their lower extremities  downwards
and backwards, and their edges present forwards and
backwards.            ...       ^
   The body of the  testicle is very firm, in conse-
quence Of its enclosure in a very firm coat called Tu-
nica Albuginea.   Upon the upper and  posterior part
of it is the protuberant substance, called Epididymis
which is less firm, being exterior to the tunica alba-
ffinea   The blood vessels  of the  testicle pass into it
on the posterior edge,  at  some  distance below the
upper end.

              The Tunica Albuginea,
   In which the body of the  testicle  is completely
enclosed,  is firm and dense; and  upon this coat its
particular  form depends.  It is of a whitish colour,
and has a  smooth external surface.  It is  thick as
well  as strong.  The  epididymis is exterior to it 
    Form and Connexions of the Epididymis.  177

It is only perforated by the  blood vessels, lympha-
tics and  nerves,  and  by the vasa efferentia, which
carry out the secretion of the testis.  One portion of
the tunica vaginalis adheres very closely to  it,  and
the other appears to contain it.   The portion which
adheres to  it is with difficulty separated, but it is a
distinct membrane.
                 The Epididymis.
   Differs in colour  from the  testicle, being more  or
less reddish.  It commences at the upper and ante-
rior extremity of the testicle,, and  passes down the
posterior edge to the lower end.
   At the commencement the epididymis is somewhat
rounded in form, and  its upper  part, or head, has
been called  the  globus  major :  as  it  descends it
lessens, and about  the  middle of the  testicle it is
flattish.
   It is firmly attached to the body of the testicle, at
the upper  end, where the vasa efferentia pass to it;
and it is also attached to it below ; but at the middle
it appears  nearly detached from it.   It has therefore
been compared to an arch resting with its two extre-
mities on the back  of the testis ; it is,  however,  in
contact with it at its middle; but about the middle
it only adheres by  one of its edges to the body of
the testis,  and generally by  its internal edge.  It has
a coat which is less firm than the tunica  albuginea of
the testicle, described on the last page.  The tunica
vaginalis of the testicle is so reflected as to cover a
great part of the epididymis which is not  in contact
with the testicle, and also those surfaces of the epi-
didymis and testis  which are in  contact with each
other and do not adhere.
             The Body of the Testicle.
   When the tunica albuginea  is cut through,  and
the substance of the testicle examined, it appears
   Vol. n.              <?3           ' 
178 Tubuli, Septa and Blood vessels of the Testicle.

to consist of a soft pulpy substance of convoluted
threads, of a yellowish  brown colour, which is divi-
ded into separate portions by very delicate septa, at-
tached to  the internal surface of the tunica albuginea
at the posterior part of the testicle.  After macera-
tion, by using a fine needle to detach them from the
cellular substance, these threads may be drawn out to
a great length. In some animals they are larger  than
in the human species; in them, it is said,  they are
evidently hollow, and  that very small  blood vessels
appear  in their  coats.   When  mercury is injected
into the vas deferens, or excretory duct of the testis,
in a retrograde course, it can be perceived in "these
ducts in the human subject.
   These delicate septa, or partitions, are  united  to
the internal surface of the  tunica albuginea  at the
posterior part of the testicle, at  which place there is
a  body called  Corpus  Highmorianum, which has
been regarded very differently by  different anato-
mists.  It is a long whitish substance, which extends
lengthwise on the posterior part of the testis; and
was supposed by  Haller to resemble one of the sali-
vary ducts.   It is now,  however, generally agreed to
be of a cellular structure,  and to contain and support
the ducts  which pass from the substance of the testi-
cle to the epididymis.
   The blood vessels pass into the body of the testi-
cle upon these septa, and are continued from them to
the filaments or tubes of which the body of the testi-
cle consists.  As  in some animals  blood vessels are
distinguished on these  tubes, there is the greatest
reason to  believe  that a direct communication  sub-
sists between them, without the  intervention of any
other structure, no other  structure havingbeen dis-
covered :  but at the same time it ought to be obser-
ved, that these tubes have not yet been injected  from
the blood vessels.  Some ingenious anatomists  have 
Blood vessels and Structure of the Testicle, #c. 179

injected the artery going  to  the  testicle so success-
fully, that the* injection has  passed  from it into the
veins coming out of the testicle;  but it is not now
said by any of them, that they have filled the tubes
in this manner.
   Mercury will pass into these vessels from the ex-
cretory duct of the testicle ; and by means of an in-
jection in that way, the structure of the testicle can
be unravelled.
   This  structure is as follows:  The cavity formed
by the tunica albuginea is divided  into a number of
apartments  by the very thin septa, or  partitions,
above mentioned.   From the filamentary or tubular
matter which fills each of these chambers, proceeds
a number of small tubes or  vessels, which observe a
straight course; they are therefore called Vasa Becta.
These vasa recta unite with  each  other and form a
net-work on the back of the testis,  within the tunica
albuginea,  which is called Bete  Testis.   From  this
net-work other vessels, from  twelve to eighteen in
number, denominated  Vasa Efferentia,  proceed
through the albuginea to  the epididymis.  These
vessels  are convoluted in such a manner as to form
 bundles of a conical form, which  are called  Com
 Vasculosi.   The number of these corresponds with
 the  number of the vasa efferentia, and they com-
 pose about one  third of the epididymis, viz. all the
 upper part of it.  The single tubes which form each
 of these cones, successively unite into one duct, which
 is convoluted so as  to form all the  remainder of the
 epididymis.  The  lower part of the  epididymis is
 turned upwards on the back of the testicle, the tube
 gradually enlarges  and is less convoluted, and finally
 becomes straight: it then takes the name of  Vas De-
ferens, and continues on  the  back of the testicle and 
180
Course of the Vas Deferens.
at the inner side of the epididymis to the spermatic

cord.*f
   A small solitary vessel or duct, has been observed

by Haller,  Monro,  and several other anatomists,  to

proceed  from the upper part of  the  epididymis:

sometimes it unites  to  the  epididymis  below, and

sometimes it proceeds upwards.   The nature of this

vessel has not been ascertained with certainty.



                   The  Vas Deferens



   Is a very firm  tube  about one line  in diameter,

which is not perfectly cylindrical exteriorly, although

the cavity formed by it is so. This cavity is so small

in diameter,  that  it will only admit a fine  bristle.

The coats of the duct have, of course,  a considera-

ble thickness.   The  internal  coat forms a soft sur-

face, analogous  to that of the  mucous  membranes:
the external is firm,  and its texture resembles that

of cartilage.  Owing to the  small size of  the cavity,

the internal coat has not been separated from the ex-

ternal.


   * De Graff" appears to have been the first anatomist who made much
progress in  the successful investigation of the structure of the testicle;
and Haller ought to be mentioned next to him, on account of the plate ex-
hibiting this structure, and the explanation of it, which he published in the
Philosophical transactions of London, for 1749.  This  plate has been re-
published by the second Monro, in the Literary and Physical Essays of
Edinburgh, and also io his Inaugural Thesis.  Haller has likewise repub-
 lished it in his Opera Minora.  It represents  not only the vasa efferentia
 and the cones formed by their convolutions, but also the rete testis and the
 vasa  recta.  Haller could inject no fuither than  this ;  but Monro and
 Hunter soon after succeeded sp as to fill a considerable portion of the body
 of the testicle with mercury, injected by the vas deferens.
   t In Mr. Charles Bell's Anatomical collection in London, there is a pre-
 paration by his assistant, Mr. Shaw, in which the tubuli testis are com-
 pletely injected with quicksilver  and unravelled.  I saw also in Leyden,
 one nearly as successfully executed by Professor Sandifort.—E»* 
Course of the  Vas Deferens.        181
  It passes  upwards  in the posterior part of the
spermatic cord,  and continues  with it through the
abdominal ring,  under and  exterior to the perito-
neum ; soon after  this iii leaves the cord and dips
down into the cavity of the  pelvis,  forming  a  curve
on the side  of the bladder, and proceeding  back-
wards, downwards and inwards.   In this course  it
crosses the  ureter, and passes between it and the
bladder.   On the lower part of the bladder the two
vasa deferentia  approach each other  so gradually,
that they appear to be nearly  parallel.  They pro-
ceed forward between the vesiculse seminales, which
are two bodies irregularly convoluted, that are  placed
in a converging  position with respect to each  other,
and communicate  with  the vasa deferentia.  The
vasa deferentia finally terminate almost in contact
with each other in the posterior part of the prostate
gland, where they perforate the urethra.  At the
distance of  about  two inches and  a half from their
termination they  enlarge in diameter, and become
somewhat convoluted.  At  the posterior margin  of
the prostate they come in contact with the anterior
extremities of the  vesiculse seminales, and unite with
them.   After this union  they  diminish in size, and
become conical; and passing a short distance through
the substance of the prostate, during which they ap-
proach each other more rapidly, they penetrate the
urethra, so  as to  open in it on each side of  a small
tubercle, called the Caput Gallinaginis, soon to  be
described.

                     SECTION II.

 Of the Vesiculse Seminales and the Prostate  Gland.

    The  Vesiculse  Seminales  are  two  bodies of  a
 whitish colour,  and irregular form, being broad and
 flat at their posterior extremities, and  terminating in 
182    Structure of the Vesiculse Siminales.

a point at the other.  Their surfaces are so convo-
luted,  that they have been compared to those of the
brain.   They are situated between  the  rectum and
bladder, and are connected to each by cellular mem-
brane.
  When the vesiculse seminales are  laid  open by an
incision, they appear  to consist of cells of a consider-
able  size,  irregularly arranged; but when they are
carefully examined exteriorly, and the cellular mem-
brane about them is detached and divided, they ap-
pear to be formed by a tube of rather more than two
lines diameter, and several  inches in length, which
terminates, like the csecum, in a closed extremity.—»
From  this tube  proceed from  ten  to fifteen short
branches, which are  closed in the  same manner.—
All these  tubes are convoluted so as to  assume the
form of the visiculae seminales above described;  and
they are fixed  in this convoluted state  by cellular
membrane, which firmly connects their different parts
to each other.   It is obvious, that tubes  thus convo-
luted^  when cut into, will exhibit the appearance  of
cells, as in the present instance.
  This convoluted tube composing the vesiculse  se-
minales, terminates  in  a very short duct, which is
nearly of  the same diameter with the vas deferens,
and this duct joins the vas deferens  so as to form an
acute angle.
  From the union of the vesiculae seminales with the
vas deferens on  each  side, a canal,  which seems  to
be the continuation  of the  vas  deferens, proceeds
through part of the prostate to the urethra, which it
perforates.  These canals are from eight to twelve
lines in' length;  they  are conical in  form,  their
largest extremity being equal to the vas deferens at
that  part.
  If air or any other fluid be  injected through the
vas deferens into the urethra, it will  pass at the same 
       Function of the Vesiculse Seminales.    183

time into the vesiculse seminales,  and distend them.
It has "been observed, that a fluid passes in this man-
ner much more readily from the vasa deferentia into
the vesiculae seminales,  than  it does from  these last
mentioned organs into the duct.
  These organs were generally regarded as reservoirs
of semen, and analogous to the gall bladder in their
functions, until the late  Mr. J. Hunter published his
opinion that they were not intended to contain semen,
but to secrete a peculiar mucous  subservient to the
purposes of generation.
  He states the following fttcts in support of his opin-
ion.
  A fluid, very different from semen,  is found after
death in the vesiculse seminales.
   In persons who have lost one testicle, a consider-
able  time before death,  the  vesiculse seminales on
each  side are  equally distended with this peculiar
fluid.   In the case of a person who had a deficiency
of the epididymis on one side and of the vas deferens
on the other, the vesiculae were filled with their pe-
culiar fluid !
  The sensation arising from redundance of the se-
cretion of the  testes, is referred  to the testes, and
not to the vesiculse seminales.
   In some  animals there is no connexion between
the vasa deferentia and the vesiculae seminales.
   See Observations  on certain parts of the Animal
Economy, by John  Hunter.

               The Prostate Gland.
   Is situated on the under and posterior part of the
neck of the bladder, so as to surround the urethra.
Its form has some resemblance to that of the ches-
nufj bjit it has a notch on the basis like  that of the
figure of the heart on  playing cards, and it is much
larger  than the chesiut of  this  part of  America. 
184
Prostate Gland.—
"The Penis.
 The basis of this body is posterior, and its apex an-
 terior ; its position is oblique, between the rectum and
 the symphisis pubis.   Below there is in some cases a
 small furrow, which, in addition to the notch above,
 gives to the gland an appearance of being divided into
 two lobes.  By turning away the vesiculae seminales
 and vasa deferentia  from the under surface of the
 bladder we bring into view a small  tubercle at the
 upper part of  the base of the prostate, called by Sir
 Everard  Home the third lobe.   When  diseased it
 projects into the cavity of the bladder.
   It adheres to the urethVa and neck of the bladder.
 Its consistence is very firm and dense, resembling the
 induration of scirrhus rather more than the ordinary
 texture of glands.
   This gland receives small branches from the neigh-
 bouring blood vessels, and has  no artery of consider-
 able size  exclusively appropriated to it.
   As it lies in close  contact with the  urethra, the
 ducts which pass between it and  the urethra are not
 to be seen separate from these bodies; but ducts ciffl
 be seen in the substance of the gland, which perfo-
 rate the urethra, and open on the sides of the caput
 gallinaginis to the number of five or six on each side.
 By pressure a small  quantity of  a whitish fluid can
 be forced  from  these orifices, "which is rather viscid,
 and coagulable in alcohol.
   The particular use of this fluid is not known,

                   SECTION III.

                  Of the Penis.
  The penis, when detached from the  bladder, and
the bones, to which it is connected, and divested of
the skin which covers it, is an oblong body, fvffich
is  rounded at one extremity and bifurcated at the
ether. 
Penis.
185
  It is composed of three parts, viz. two oblong bo-
dies, called Corpora Cavernosa, which, at their com-
mencement, form  the bifurcated portions, and then
unite to7compose the body of the organ; and a third
part, of a spongy texture, which is connected to these
bodies where they unite to each other, on the under
side, and continues attached to them during the whole
extent of their union, terminating  in an  expanded
head which covers the anterior extremities  of the
corpora cavernosa.   The urethra  passes from  the
neck of the bladder, on the under side of  the penis,
to its anterior extremity, invested by this third body,
which  is therefore called Corpus Spongiosum  Ure-
thrse.
  The two bifurcated  extremities are attached each
of them to one of the crura of the pubis and ischium;
and they unite to  form the body of the penis imme-
diately anterior to the symphisis pubis, to which the
lower  part of it is also attached; so that the penis is
firmly connected to the middle of the. anterior part of
the pelvis.  The urethra proceeds from the neck of
the bladder, between the crura of  the ischium  and
pubis and the crura of the penis, to join the body of
the penis at its commencement,  and near this place
its connexion with the corpus spongiosum begins; so
that there  is a small  portion of the  urethra between
the neck of the bladder and the commencement of ,the
corpus spongiosum, which is not covered by the cor-
pus  spongiosum.  This is called the membranous part
of the urethra.                                 \
  The penis, therefore,  consists of two oblong bo3',
dies of a cellular structure, which originate sepa^,ate«',
ly, but unite together to form it; and of the urethra,
which joins  these  bodies  immediately after their
union, and is invested by a spongy covering, which
by its expansion  forms the anterior extremity not
only of the urethra but of the whole penis.  These
   Vol, ii.              24 
186
Corpora, Cavernosa Penis.
 three bodies, thus arranged and connected, are cover-
 ed by cellular membrane and skin in a manner to be
 hereafter described.

             The Corpora Cavernosa,
  Which compose the body of the penis, are two ir-
 regular cylinders, that are formed by a thick dense
 elastic membrane, of a whitish  ligamentous  appear-
 ance and great firmness.  They are filled with a sub-
 stance of a cellular structure, which is occasionally
 distended with blood.  The crura of these cylindri-
 cal bodies,  which are  attached to the crura of the
 ischium and pubis, are small and pointed at the com-
 mencement, and are united to the periosteum of tho
 bones.   In their progress upwards they enlarge, and
 at the symphisis of the pubis they unite so as to form
 an oblong body, which retains the appearance  of a
 union of two cylinders applied to each other length-
 ways; for above there is a superficial groove passing
 in that direction,  which is occupied by a large vehrf
 and below there is a much deeper groove, in whieh
the urethra is placed.   Between these grooves  is a
septum which divides one side of  the penis from the
other.   It appears to proceed from the strong mem-
brane which forms the penis, and is  composed of
bundles of  fibres, which pass from one  groove of the
penis to the other, with many intervals between them,
through which blood or injection passes very freely.
Sometimes  these bundles of fibres, with their inter-
vals, are so regularly arranged, that they have been
compared to the teeth of a comb.  This septum ex-
tends from  the union of the two crura to their termi-
nation.
  Each of  these cylinders is penetrated by the main
branch of the pudic artery, which is about equal in
size to a crow's quill.   These arteries enter the  cor-
pora  cavernosa  near  their union> and continue 
          Cells of the Corpora Cavernosa.      187

through their whole extent,  sending off branches in
theircourse; the turgescence and erection of the penis
is unquestionably  produced by the blood which flows
through these  vessels into the penis.
  The interior structure of the penis, when examined
in the recent subject, is of a soft spongy nature, and
seems stained with  blood.   If any fluid be  injected
through the  arteries this substance appears  cellular,
and may be completely distended by it.   When air
iS injected, and the structure becomes dry, the penis
may be  laid open; the cellular structure then appears
as if formed  by a  number of lamina and of filaments,
which proceed from one part of the internal surface
of the penis  to another, and form irregular cells.   It
has been compared to the lattice-work in the interior
of bones;  and it is suggested by M. Roux,  that  the
fibres of which the structure consists resemble those
of the strong elastic coat of the penis.*  If these cells
are filled with coloured wax, injected by the artery,
and the animal substance is then destroyed by placing
the preparation in a corroding liquor, the wax which
remains shows that the membranes  forming the cells
are very thin.
   These cells  communicate freely with each other;
and therefore, if a pipe be passed through the strong
coat of  the penis, the whole of them can be filled from
it by the ordinary process of injection.

  *  Mr. John Hunter says on this subject,  " That the cells of the corpora
cavernosa are muscular,  although no such appearance  is to be observed in
men: for  the penis in erection is not at  all times equally distended.  The
penis, in a cold day, is not so large in erection as in a warm one : which
probably arises from a kind of spasm, that could not act if it were not raws,*
cuhr.
  In the horse, the parts composing the cells of the penis appear evident-
ly muscular to the eye, and in a horse just killed, they contract upon being
stimulated."—Ed. 
18;->       Corpus Spongiosum.—Bulb.

                  The Urethra.

  Is a membranous  canal, which extends from the
neck of the bladder to the orifice at the extremity of«
the penis;  and for a very great part of its length is
invested  by a spongy structure, called the  corpus
spongiosum urethra.   It proceeds  from the neck of
the bladder along the upper part  of the prostate;
from the prostate it continues  between the crura of
the penis until their  junction: it then  occupies the
great groove formed by the corpora  cavernosa on the
lower side of the penis, and continues to the orifice
above mentioned. At a small distance from the pros-
tate gland the spongy substance which invests it com-
mences, and continues to its termination.   After this
spongy substance has arrived at the termination  of
the corpora cavernosa, it expands and  forms a body
of a particular figure which covers the extremities
of  the corpora  cavernosa, and is  denominated the
Glans Penis.
  The Corpus Spongiosum begins at the distance of
eight or ten lines from the anterior  part of the pros-
tate.  It is much larger at its commencement than at
any other part except the glans, and this enlarged
part is called the Bulb.  It surrounds the whole  of
the urethra, and with the exception of the bulb and
the glans penis,  is of a cylindrical figure.  It is form-
ed by a membrane which has some resemblance to the
coat of the  penis, but is much thinner, and by a pe-
culiar spongy substance, which occupies the space be-
tween the internal surface of this membrane and the
external  surface of the canal  of the urethra.  The
membrane and the spongy substance, form a coat  to
the urethra, which, with the exception of the enlarge-
ment before mentioned, is about one line thick. After
this spongy substance has arrived at the termination,
its coat adheres firmly to the coat of the penis. 
      Structure of the Corpus Spongiosum.   189

  The Bulb, or first enlargement of the corpus spon-
giosum, is oblong, and rather oval in form ; it is mark-
ed by a longitudinal depression in the middle, which
is very superficial.  It consists entirely of the spongy
substance above meutioned.
  The  Glans Penis is also composed of the  same
spongy  substance,  but the coat which covers it is
more thin and delicate than that of the other parts of
the urethra.   The lower surface of the glans is fitted
to the extremities of  the corpora cavernosa, but it is
broader than  the  corpora cavernosa, and  therefore
projects over them on the upper and lateral parts of
the surface of the penis.   The edge of the promi-
nent part is regularly rounded, and is  denominated
the  Corona Glandis.
   Several small arteries pass to this spongy structure.
The pudic artery, as it passes on each side to the cor-
pora cavernosa,  sends a branch to the bulb of  the
urethra.   The same vessel in the substance of  the
penis, also sends branches to the  urethra : and  the
artery on the back of the penis terminates in small
branches, which penetrate the substance of the glans.
   By these vessels  blood is carried to  the spongy
substance of the urethra, which  is  occasionally  dis-
tended in the same manner that the cavernous bodies
of the penis are distended during the erection of that
organ.   But the cellular structure of this organ is
not so unequivocal as that of the corpora cavernosa;
for  if it be injected with coloured  wax, and corroded
in the usual manner, the injected  matter will exhibit
an appearance which has  the  strongest  resemblance
to a convoluted vessel, like the vas deferens  in  the
epididymis.*

   * Mr. Hunter says,  «' that the corpus spongiosum urethra and glans
 penis are not spongy or cellular, but made up of a plexus of veins.  This
 structure is discernible in the human subject; but is much more distinctly
 seen in many animal*, as the horse," &c—Ed. 
190      Internal Surface of the Urethra.
            The Canal of the Urethra,
  Which conveys the urine from the bladder, is a very
important part of the urinary organs.  It consists of
a vascular membrane with a smooth surface, which is
perforated by the orifices of  many mucous follicles,
some of which are of considerable size.   It is  ex-
tremely sensible, and has so much power of contrac-
tion,  that  some  persons  have  supposed muscular
fibres to exist in its structure.
  It is differently circumstanced in different parts of
its course.  While surrounded with the prostate it ad-
heres firmly to that body, seeming to be supported by
it;  and here its diameter is larger than it is farther
forward.  On the lower or posterior side  of this por-
tion of the urethra,  is an oblong eminence, called
Verumontanum,ov Caput Gallinaginis,  which com-
mences at the orifice of  the  urethra, and continues
throughout the whole portion that is surrounded by
the prostate gland, terminating at the  point of that
body. The posterior extremity of this tubercle begins
abruptly, and soon becomes thick and large ; ante-
riorly it gradually diminishes to a line, which is some-
times perceptible for a considerable  distance in  the
urethra, in a straight forward direction.  In the upper
edge or top of this body is a groove, which is produced
by a mucous follicle ; on the lateral surfaces, anterior
to the'middle, are the orifices of the common ducts of
the vesiculae seminales and vasa deferentia, (see page
182,) which are sufficiently large to  receive a thick
bristle.  Near these, on each side, are five or six smaller
orifices  of the excretory ducts of the prostate gland.
At the distance of an inch before the extremity of the
bulb of  the urethra, in the lining membrane, are the
openings of two ducts, one on each side,  that lead to
small glandular bodies called Cowper's glands, which
are situated on each side of the urethra below the bulb,
but are covered by the acceleratores urinse muscles. 
          Mucous Ducts of the Urethra.      191

  The diameter of the urethra lessens after it leaves
the prostate.   That portion of the canal which is be-
tween this gland and  the bulb, without investment,
and therefore  called the membranous part,  is the
smallest in diameter.
  After it is invested with the spongy substance, it
has a small enlargement, and then continues  nearly
of one size, until it arrives near the glans penis, when
it again enlarges and alters its form,  being  no longer
cylindrical but flattened.  Its broad surfaces  have
now a lateral aspect.
  From the bulb of the" corpus spongiosum  to this
last enlargement, the appearance of the inner surface
of the urethra is uniform.   The membrane  is thin
and delicate, and in a healthy subject, who has been
free from disease of these  parts, is of a whitish  co-
lour ;  but bloodvessels are very perceptible in it.
When it is  relaxed, it appears to  be thrown  into
longitudinal wrinkles; but it  admits of considerable
extension, being somewhat elastic:   when extended,
its  surface  appears smooth,  as if  it were covered
with an epithelium.   Mr.  Shaw,  of London,  has
described a set of vessels immediately below the in-
ternal membrane of the urethra, which,  when empty,
are very similar in appearance to muscular fibres.—•
He says he has  discovered  that these vessels form
an internal spongy body, which passes down to  the
membranous part of the urethra, and forms even a
small bulb there.  His preparation with a quicksilver
injection of the part  is certainly a very satisfactory
proof  of its existence.*  Throughout the  whole ex-
tent of this part of the urethra, are the orifices of a
great  many mucous ducts or sinuses, which pass
obliquely backwards.  Many of these  are so  small
that they cannot be penetrated by a  bristle, or probe

     * S'^e Med* Chirurg — T.-aasactioas of London-—vol. 10th. 
192
Mucous Ducts of the Urethra.
   of that size; but some are larger.  It has not been
   observed that  any glandular body immediately sur-
   rounds them, although they secrete the raucous with
   which the urethra is lubricated.—On the lower side
   of the urethra, near the commencement of the glans
   penis, there is one or more  of them,  so  large  that
*  their orifices sometimes  admit the  point  of a small
   bougie.*
     These organs, when inflamed, secrete the puriform
   discharge which takes place in gonorrhoea.—In a na-
   tural state they produce the  mucous which  is  con-
   stantly spread over the surface of the urethra, to de-
   fend it from  the acrimony of the urine,  and which
   passes away with that fluid unperceived.
     The surface of the  urethra is  endued  with great
   sensibility,  and is therefore  liable to great irritation
   from contact with any rough  body or any acrid  sub-
   stance.  Irritation, thus excited, induces a state of
   contraction, which is  particularly remarkable, as no
   muscular fibres are to be seen in its structure.—When
   a bougie has been passed into the urethra for a consi-
*   derable distance, if it cannot proceed the whole way,
   it sometimes happens that the instrument will be dis-
   charged by a steady uniform motion, which seems to
   proceed from a progressive contraction of the urethra,
   beginning very low down. At particular times, after
   the urethra has been much irritated, it will not receive
   a bougie, although at  other  times a bougie of equal
   size may be passed to the bladder without opposition.
   This cannot depend upon that elasticity  which was
   noticed before.f


    * They were discovered by Plazzoni, of Padua, in 1621.  Their number,
   according to Loder, amounts to about 65—See his plates. Ed.
    t Sir Everard Home, whose professional opinions are of great weight,
   has lately described in the Transactions of the Royal Society, the appear-
   ance of the Fining membrane of the Urethra, when viewed  through a 
         Contractile Power of the  Urethra.     193

   Upon the two crura of the  penis, or the beginning
of the corpora cavernosa, are fixed the muscles call-
ed Erectores Penis, which are described in the first
volume.*  These  muscles cover  the crura of the
penis from their origin to their  junction, and not
only compress them, but also influence the motion of
the penis when it is distended.
  The bulb of the urethra is covered by a muscular
coat, called the Accelerator Urinx* which has the
effect of driving forwards any fluid contained in the
cavity of the urethra,  and also of giving  the  same
direction to  the  blood in that part of the corpus
spongiosum.  There is also the Transversus Perinei
on each side, that passes transversely from the tube-
rosity of  the ischium to the bulb of the urethra.—
Finally the lower part of the sphincter ani muscle,
which is nearly elliptical in  form  is inserted by its
anterior point into the muscular covering of the bulb
of the urethra.   Upon removing the  integuments,
these muscles  are in view;  and  the course of the
urethra from the  bladder is  concealed,  particularly
by the  anterior point of the sphincter ani.  When
the sphincter ani is dissected away from its anterior
connexions, and the cellular  and adipose  substance,
which is  sometimes very abundant, is also removed,
the  lower surface of the  membranous  part of the
urethra  may be brought into view, as  it proceeds
from the  prostate  gland to  the balb of the  corpus
spongiosum, f
microscope of great powers.  From this paper it seems that he is fully
convinced of its muscular structure.—Ed.
  * See description of " Muscles about the Male Organs of Generation"
Vol. I. Part II. Chap. fl.
  t The natural situation of the membranous part of the uretnra,  and of
the prostate gland, as well as their relative position with respect  to the
sphincter ani, rectum, &£. can be best studied by a lateral view of the
  Vol. ii.               35 
191     Contractile Power of the Urethra.


   When the accelerator urina  is  removed from the

bulb of  the urethra, there will  appear  two  bodies,

which  have some   resemblance  to   flattened  peas.

They  lie one on each side of the urethra, in contact

or nearly so with its bulb, and from  each gland pro-

ceeds  an excretory duct of an inch  and a quarter in
length, between the corpus spongiosum and the lining

membrane of the canal of  the urethra, and opens into
the latter.  Its  orifice is  found with some difficulty,
but is large enough to admit a bristle.  These arc

Cowper's glands.*
   The penis is connected to the symphisis pubis by

a  ligamentous substance,   which proceeds  from the

back or upper surface  of  the organ  to  the anterior

part of the symphisis,  and connects these parts firm*

ly to each other.
   Thus  constructed, of  the corpora cavernosa and

the urethra with its corpus spongiosum, and attach-

ed to  the pelvis as above  mentioned, the penis is in-

vested with its integuments in  the following  man-

ner.!


contents of the pelvis ; which is  to be obtained by removing carefully
one of the ossa innominata, and dissecting the parts which were enclosed
by it.
  * These glands were discovered  by Mery, in 1684, and described by
Cowper, in 1699.  A third gland, smaller than the preceding, connected
with the curve of the urethra under the symphisis pubis, was discovered by
Cowper, and Morgagni speaks of having observed a fourth.—Ed.
  t There are several fascise  and ligaments about the perineum which
should be connected with the account of its viscera. Immediately beneath
the skin of the perineum is the Perineal Fascia, a thin but strong mem-
brane, which extends from bone to bone, occupying  the space between
 the anus and the posterior part of the scrotum. It  is rather better seen in
 lean subjects thaa in  fat  ones, for in the latter it is converted in part into
 adipose membrane.   When a rupture occurs in the  posterior  part of
 the urethra,  this  fascia prevents  the urine from showing itself immedi-
 ately in the perineum, and drives it into the cellular structure of the
 scrotum.
   Immediately beneath the perineal fascia are pbced the muscles ; when
 they are removed the bulb of the urethra may be seen very advantage-
 ously,  extending in the middle of the perineum almost to the ?w  It is 
Integin:ir.nts of the Penis.         195
             Integuments of the Penis.

  The glans penis,  the structure of which has been
already described, is covered  by a  continuation  of
the skin, which appears  altered  in its texture so  as
to resemble in  some respects the skin of the lips,  and
in like manner is covered by  a delicate  production
of cuticle.
  Around the  corona of  the  glans,  especially on its
upper part, there are whitish tubercles, which are of
different sizes in different persons,  but always very
small.  The skin adheres firmly to the whole extent
of the corona of the glans, and  is  very delicate in its
structure as it continues from the glans upon the
body of  the penis;  but it gradually changes so as  to
assume the appearance  and structure  of a common
skin, and continues in this state over the penis. The
adhesion of the  skin to the ligamentous  coat of the
corpora cavernosa also  becomes  more loose,  owing
to the quantity and texture of  the cellular substance
which connects them.  The skin thus connected  to
the penis, has  commonly more length than  that or-
gan,  even in its extended state.  In  consequence  of
this greater length, and of its adhering firmly around
the  corona  glandis,  it  necessarily forms' a  circular

not loose and pendulous, but is attached by its pelvic surface to the trian-
gular ligament of the urethra.  This ligament is a septum between  the
perineum and the pelvis, and connects itself to the pelvic  or internal
edges of the rami of the pubis and ischii as far down rs the organs of  the
crura penis. It extends from the arch of the pubis to the line mentioned,
and fills up all the space between the bones of the opposite sides.   It
consists of two lamina, and Cowper's glands are placed between them.
About an inch below the symphisis pubis a perforation is  made in this lig-
ament for the passage of the membranous part of the urelhra.
  Just below the symphisis pubis, between the two lamina of the triangu-
lar ligament, is placed a much stronger ligament called the pubic, which is
about half an inch broad, its lower edge is thick and rounded.  For further
detail on the subject of the fascial of the pelvis, see L^sons in Prartiral
Anntoiny by the prc^nt editor —En. 
190         Integuments of the Pcni?.

fold or plait, which varies in  size according to the
length of the skin.  This fold is generally situated at
the commencement of the firm attachment of the skin
to the body of the penis, or around the glans; but it
may be formed any where upon the body of the  penis
by artificial management.
   This duplicature, or fold of the skin, when it takes
place so as to cover the glans, is called the Prepuce;
and the skin which is very tender and delicate for
some distance from the glans, form that surface of the
prepuce which is in contact with the glans when it
covers that body.
   There  is  also  a  small fold of the skin, which is
longitudinal  in its direction, that commences at the
orifice of the urethra, and extends backwards, on the
lower surface of  the  penis.  It is unvarying  in its
position,  and is called the Frenum.
   It is a general observation, that adeps is not  found
in the cellular substance which connects the skin to
the body  of  the penis; but this cellular substance is
distended with water in some hydropic cases.
   From  the skin immediately below the glans, and
from  small  follicles on  each side  of  the  frenum, is
eecreted an unctuous  fluid, which, when  allowed to
continue, becomes inspissated, and acquires a caseous
consistence and colour, as well as a  peculiar odour.
It sometimes also acquires an acrimony which produ-
ces inflammation on  the surface with which it is in
contact, as well as the copious  secretion of  purifopm
fluid.
   The distribution ef the pudic artery in the penis,
has already been mentioned;  and a further account
of its origin and progress  to its destination, will be
found in the general account of the arteries.   Some-
times small branches  of the external  pudic arteries,
which originate  from the femoral, are extended to
the penis: and it has been asserted,  that  branches of 
  Blood Vessels and Absorbents of the Penis. 197'

the middle hemorrhoidal artery have also been found
there, but this does not often occur.
  The Veins of the penis are of two kinds: those
which originate in the corpora cavernosa, accompany
the corresponding branches of the pudic artery, but
communicate more or  less with the plexus of veins
on the lower and lateral part of the bladder.  There
is also a great  vein,  which  occupies the groove on
the back of the penis, between the  corpora caver-
nosa, that appears particularly appropriated to the
corpus spongiosum urethras; for it originates in the
glans penis, and receives branches from the urethra
as it proceeds  backwards.  There are  often two of
these  veins, one in the groove, and the other  more
superficial:  they generally unite near  the root of the
penis.  The common trunk then passes between the
body  of the penis and the symphisis pubis, and ter-
minates in a plexus of veins at the neck of the blad-
der, which  is connected to the plexus above men-
tioned on the  lower and lateral parts of  the same
viscus.
  The Absorbent Vessels of the penis take two differ-
ent directions on each side.   Those which  arise from
the integuments generally, unite so as to form a few
trunks on the back of  the  penis, which divide near
the root of  the  organ, and proceed to  the glands of
the groin.  Those whieh originate from the interior
parts of the penis, accompany the blood vessels, and
terminate in the plexus of  lymphatics in the pelvis.
   It ought  to  be noted,  that the superficial lympha-
tics generally enter the  upper inguinal  glands.
   The Nerves of the  penis are principally derived
from  the lower secral  nerves, which  unite  in the
plexus that forms the great ischiatic.  From these
 nerves a branch on each side originates, which passes
 like the pudic artery, between the sacro-sciatic liga-
ments.  In this course it divides into two  branches, one 
398      Nerves.—General Observations.
of which passes below to the muscles of the penis and
urethra, and to  the contiguous parts;  and some of
its branches seem finally to terminate in the dartos:
the other branch proceeds along the crura of the pu-
bis and ischium,  and passing between the  symphisis
pubis and the body of the penis, arrives at the upper
surface or dorsum of the penis, along which it conti-
nues on the outside of the veins to the glans, in which
it  terminates.   In this course  it  sends off several
branches, some of which terminate in the integuments
of the penis.

    After an examination of the relative situation of the mus-
      cles and blood vessels of the male organs of genaration,
      there appears reason to doubt, whether the erection of
      the penis can be referred to pressure upon the veins
      which return from that organ.  Albinus has written on
      this subject.  See Academicarum  Annotationum, lib.
      ii. caput xviii.  Haller has  also considered it, and
      stated the opinions  of several anatomists, in his Ele-
      menta Physiologiao, torn. vii. page 555.
    The manner in which the urine is confined in the blad-
      der does not appear to be clearly understood.  The
      connexion of the neck of the bladder with the prostate,
      and the appearance of the contiguous parts of the blad-
      der, do not render it probable that these parts act like
      a sphincter.   The late J. Hnnter, who paid great at-
      tention to the functions of these organs, was very  de-
      cided in his  opinion that the contraction of the urethra
      produced the effect of a sphincter of the bladder.  He
      lias published some very ingenious observations respect-
      ing the manner in which urine is discharged from  the
      bladder, in his Treatise on the Venereal Disease, part
      III. chapter IX.
    Mr. Hunter also long since asserted, that the vascular
      convoluted appearance of the corpus spongiosum ure-
      thrae was more distinct in the horse than the man.  In
      the fifth volume of the Lecons d'Anatomie Comparee
      of Cuviery the very learned and ingenious author con-
      firms the declaration of Hunter, respecting the vascu-
      lar convolutions of the corpus spongiosum of the horse.
      He states, that the corpora cavernosa of the penis of
      the elephant appear to he filled in  a great degree with 
General Observations.
199
  the ramifications of veins, which communicate with each
  other by such large and frequent anastomoses, that they
  have a cellular appearance. A similar structure exists
  in the horse, camel, bullock, deer, &c. and in them all
  these  communicating branches can be distinguished
  from those which extend the whole length of the penis.
The corpus spongiosum urethra?, according to  M. Cu-
  vier, is constructed in a similar manner.   From these
  facts he is induced to believe  that this structure per-
  vades the whole class of mammalia. 
CHAPTER VI.
     OF THE FEMALE ORGANS OF GENERATION.

   The female organs of generation consist of the
 Uterus and Ovaries, with their appendages; and of
 the  Vagina, with the structure which surrounds its
 external orifice.  The uterus is situated in the pelvis,
 between the  bladder  and rectum; and the ovaries
 are on each side of it.  The vagina is a vejy large
 membranous canal, which  passes  from  the uterus
 downwards and forwards, also between  the bladder
 and rectum, and opens externally.
   Connected with the orifice of the vagina are seve-
 ral bodies, which are  called the external parts of
 generation, in order  to  distinguish them from  the
 uterus and ovaries, and  their appendages, and also
 from the canal of the vagina ; which are called the     j
 internal parts.                                      m
   The bladder of urine lies above and in contact with    1
 the vagina : the urethra  is also intimately connected
 with it.  The description of the bladder and urethra    .*
 is  therefore placed at the end of this chapter.

                    SECTION I.

      Of the External Parts of Generation.'>

   The adipose membrane,  immediately  anterior to
the symphisis pubis, and on each side of it, forms a
considerable prominenee in females, which, at the age
of puberty, is covered with hair, as in males.  This
prominence is denominated the Mons Veneris.
   The exterior orifice commences immediately be-     .i
low this.    On each side  of this  orifice is a promi 
           Labia Externa.—Clitoris.        201

nence continued from the mons veneris, whicli is
largest above, and gradually diminishes as it descend.-.
These prominences have some hair upon them. They
are called the Labia Externa.   Their junction be-
low is denominated the Fourchettc.   The space be-
tween the place of their junction and the anus is ra-
ther more than an inch in extent, and is denominated
the Perineum.
   As the skin which forms the labia  is continued in-
ternally, it becomes more thin and soft, and is cover-
ed by a more delicate cuticle.   It is also more or le?s
florid, and secretes a peculiar mucous.
   In the upper angle, formed by the labia externa,
is the upper extremity and glans of the clitoris.
   The  Clitoris is  a body which has a very strong
resemblance to the penis, but there is no urethra at-
tached to it.  It has two crura of considerable length,
which originate, like those of the penis, from the
crura of the  pubis and ischium, and unite at the
symphisis of the pubis so as to form a body, which
is not  much more than an inch in  length, and is
broad in proportion.   The extremity of this organ,
called  the  Glans of the Clitoris, forms a small tu-
bercle,  which is covered above and on the sides by a
small plait or fold of the skin, denominated the Pre-
puce.   These  parts  are lubricated  by a  secretion
similar to that which is observed round the  glans
penis.
   The  crura of the clitoris have muscles similar to
the erectores penis.   The interior  structure of the
CUtoris is very similar to that of the corpora caver-
nosa of the penis, or the  corpus spongiosum of the
urethra. It appears constructed for  a similar disten-
tion, and is endued with the same sensibility as the
penis.  The two lateral parts are also separated from
  ach other by a septum, resembling that of the pen?5.
 It is united to  the symphisis pubi* by a limment
   Vol. u,              26 
 ^02           Nymphse.—Hymen.

   The Prepuce  of the  clitoris has a semicircular
 form : below its extremities two folds or plaits com-
 mence, one on each side, which are situated obliquely
 with respect to each other, so as to form an angle.
 These folds are denominated the Nymphse.
   The Nymphse extend from the clitoris downwards
 nearly as far as the middle of the orifice of the vagina.
 They are situated within the external  labia, and are
 formed by the skin after it has become more delicate
 in its texture.  Their surface however is often some-
 what corrugated.   There are many blood vessels in
 their internal structure, and it is supposed they are
 occasionally somewhat tumid.   They are flat,  and
 their exterior edge is convex; so that they are nar-
 row at their extremities, and broad in the  middle.
 Their breadth is very variable, and in some instances
 is great.  In a majority of cases, it is equal  to one-
 fourth of  their length.  Their colour in young sub-
 jects is of a bright red; in women advanced in years
 and who have  had many children, they are of a brown
 red, and sometimes of a dark colour.
   The use of these parts is not very evident. They
 have been supposed  to regulate the course of the
 urine as it flows from the urethra, but their effect in
 this respect is not great.   They  have also been sup*
 posed to  favour  the necessary  enlargement of  the
 parts in parturition.
   The orifice of the urethra is situated about an inch
 and one quarter further inward than the clitoris.   It
 is often rather less than the diameter of the urethra,
 and is somewhat protuberant.  The orifices  of mu-
 cous ducts are to be perceived around it.
  The orifice of the urethra is at the commencement
 of  the  canal of  the vagina.   Immediately  within
 this orifice is  situated  the  membrane denominated
Hymen.
  The. Hymen is *p incomplete septum, made by a 
The  Vagina.
203
fold or daplicature of the membrane which forms
the surface contiguous to it.   Sometimes it is circu-
lar, with  an aperture  in the  centre.  Sometimes it
has a resemblance to the crescent, the  aperture be-
ing at the  upper part of it.   The hymen has fre-
quently been found without a perforation, and has
therefore prevented the discharge of the  menstrual
evacuation.  It is generally ruptured in the first in-
tercourse of the sexes; and  some small  tubercles,
which are found on the surface of the vagina near the
spot where it was  situated, are supposed  to be the
remains of it.  These tubercles are called Carunculx
Myrtiformes.

                   SECTION 11.

                 Of  the Vagina.

   The canal of the vagina, commencing at the hy-
men and  the orifice of the  urethra,  is  rather more
narrow at its beginning than it is  further inward.—
From this place it extends backwards and  upwards,
and partakes in a small degree of the  curve of the
rectum:  while the bladder, which is above it, and
rests upon  it, increases the curvature of the anterior
part.   It is much larger  in  women who  have had
children  than in those who have not
   The membrane  which lines the vagina  resembles
to a certain degree,  the membranes which secrete
mucous in  different parts of  the  body.   Its surface
appears to  consist of very small papillse ; and at the
anterior  extremity  of the  vagina it forms a  great
number of  rugae, which are arranged in a transverse
direction, both on the  part of the vagina  connected
to the bladder, and on that part which is connected to
the rectum, while the lateral  parts of the vagina nrr 
204 Corpora Cavernosa.—Sphincter Vagime.

smooth.  These rug» are most prominent in the mid-
dle : so that  a raised line appears to pass  through
them at right angles.  This line extends from with-
out inwards.   The rugze on the part next to the blad-
der are the strongest.
   This arrangement of the surface of the vagina does
not extend beyond the external half of the canal: on
the internal half part, or that nearest the uterus, the
surface is smooth.
   The rugee are  considerably diminished in women
who have had children.
   Throughout this surface are to be  seen, in some
cases with the naked eye, the orifices of mucous foli
licles or ducts, which occasionally discharge  conside-
rable quantities of mucous.
   Exterior to this lining  membrane of the vagina is
a dense cellular structure, which  has  not yet been
completely investigated: it is of a lightish colour, and
has some resemblance to  the texture of the body of
the uterus.   It is  very vascular, and appears to be of
a fibrous structure.  It may be very much distended,
and seems to have a  contractile power.
   At the anterior  extremity of the vagina,  on each
side of it, there is superadded to this, a cellular, or
vascular  substance, from eight lines to an inch in
breadth ;  which,  when cut into, resembles the cor-
pora cavernosa, or the corpus spongiosum of the pe-
nis.  These bodies commence near the body of the
clitoris, and extend downwards on each side of the
vagina.  They have been called Plexus Bcteformis,
and Corpora Cavernosa Vagime, and are supposed
to be occasionally distended with blood, like the cli-
toris and penis.
   These corpora cavernosa are covered by muscular
fibres,  which pass  over them on each side from the
sphincter ani to the  body of  the clitoris; to each of
which  organs they are attached.   These fibres con- 
Unimpregnated Uterus.
205
stitute the sphincter vagina muscle, and contract the
diameter of the vagina at  the  place where they are
situated.
  The transversus perinei  muscles also exist in the
female.  They pass from the tuberosities of the ischia,
and are  inserted into a dense whitish substance in
the perineum, to which the anterior extremity of the
sphincter ani is likewise attached.
  The vagina is in  contact with the rectum behind ;
the bladder lies upon it and anterior to it.  A small
portion of peritoneum, to be reflected to the rectum,
is continued from the uterus upon  the posterior part
of it.  The  lateral portions of it  are  invested with
cellular substance.  The  anterior extremity of the
uterus, which is called the Os Tincse, projects into
it from above.
                   SECTION III.

Of the  Uterus, the Ovaries and their Appendages.
                   The Uterus

  Has been  compared to  a pear with a long neck.__
There is of course a considerable difference  between
the body and neck ; the first being twice as broad as
the last.   Each of these parts is somewhat flattened.
   In subjects of mature age, who  have never been
pregnant, the whole of the uterus is about two inches
and a half in length, and  more than  one  inch and a
half in breadth at the broadest part of the body: it
is also near an inch in thickness.
  It  is generally larger  than this in women  who
have  lately had children.
  The uterus is situated in the pelvis between the
bladder and rectum, and is enclosed in a duplicaturc
or fold of the peritoneum, which forms a loose septum
that extends  from one side of the pelvis to the other,
and divides it into an anterior and posterior chpiv 
20ti
Ligaments of the Uterus.
 ber.   The posterior surface of this septum is oppo-
 sed to the rectum,  and the anterior to the bladder.
 The two portions of this septum, which are between
 the uterus and the  lateral parts of the pelvis, are
 called the Broad Ligaments.
   On the posterior surface, the Ovaries are situated
 on each side of the uterus, being enclosed  by a pro-
 cess of the ligament or septum.  Above them, in the*
 upper edge of the septum, arc the Fallopian Tubes,
 which are ducts that commence at the upper part of
 the uterus on each side,  and proceed in a lateral di-
 rection for some distance, when they form  an angle
 and incline downwards to the ovaries.   These ducts
 are enclosed between the two  lamina of the  septum
 for the greater part of their length.
   The peritoneum, which forms the septum, is re-
 flected from it, posteriorly, to  the rectum  and  the
 posterior surface of the pelvis, and anteriorly, to the
 bladder.   In its progress, in each direction, it forms
 small plaits or folds; two of which extend from the
 uterus to the rectum posteriorly, and two more to the
 bladder anteriorly :  these are  called the  Anterior
 and Posterior Ligaments of the Uterus.
   The other ligaments, which  proceed  more imme-
 diately from the uterus, are called the Bound Liga-
ments.  These arise from each side of the uterus, at
a small distance before and below the origins of the
fallopian tubes, and proceed in an oblique course to
the abdominal rings.  Tbese ligaments  are also in-
vested by the peritoneum.  They pass through  the
rings and soon terminate.
   In the  body of the uterus is a cavity, which ap-
proaches  to the triangular form; and from which a
canal proceeds through its neck.   This cavity is so
small that its sides are almost in contact, and the ca-
nal is in proportion; so that this organ is very thick
in proportion to its bulk. 
       Structure and Cavity of the Uterus.    207

  The substance of which the uterus consists is very
firm and dense : it is of a whitish colour, with a slight
tinge of red.   There are  many blood vessels, with
nerves and absorbent vessels,  in  its texture.  The
nature and  structure of this substance has  not yet
been precisely ascertained.  It appears very different
indeed from muscle ; but the uterus occasionally con-
tracts, with great force,  during labour.   It is not ren-
dered thin by its enlargement during pregnancy, and
the blood  vessels in its texture are greatly enlarged
at that time.
  Exteriorly, the uterus is covered by the peritone-
um, as has already been mentioned.   Internally it is
lined with a delicate membrane that has some resem-
blance to those which secrete mucous, and is gener-
ally of a whitish  colour, abounding with  small orifi-
ces that can be seen with a magnifying glass.  This
membrane is so intimately connected to the substance
of the uterus that some anatomists have supposed it
was merely  the internal surface of that substance, but
this opinion is now generally abandoned.   It is  sup-
posed that the colour of this membrane is  more florid
about the period of menstruation.
   The cavity of the uterus, as has been observed be-
fore, is triangular in form.  When the organ is in its
natural position, the upper  side of  this triangle is
transverse with respect  to  the body, and the other
sides pass downwards and inwards.   In each of the
upper angles are the orifices of the fallopian tubes,
which are of such size  as to admit a hog's bristle.
   The two  lower lines of the triangle are slightly
curved outwards at their upper extremities ; so that
the upper angles of the triangle  project outwards,
and the orifices of the fallopian tubes  are nearer to
 the external surface than they otherwise  would be.
   The lower angle of the cavity of the uterus is ocn 
20b   Structure and Cavity of the Uterus.

cupied  by the orifice of  the  canal,  which passes
through the neck of the organ ; this  orifice is from
three to four lines in diameter.  The  canal is about
an inch in length,  and is rather wider in the middle
than at either end.  On  the anterior  and posterior
portions of its surface are  many small ridges which
have  an arborescent arrangement, one large ridge
passing internally  from  the commencement of the
canal, from which  a  number of other ridges go off in
a transverse direction.  These  ridges extend nearly
the whole length of  the canal.   In the grooves, be-
tween the ridges, are the  orifices of many mucous
ducts.  There are also  on  this surface a number of
transparent bodies of* a round form, equal in bulk to
a middle sized grain of  sand ; the nature and use of
which is unknown.  They have been  called Ovula
Nabothi,  after a physiologist, who published  some
speculations respecting their use, about  the  com-
mencement of the  last century.
  The canal of the  neck of the uterus is very dif-
ferent from other ducts,  for it seems  to be a part of
the cavity to which it leads, and when the cavity of
the uterus becomes enlarged in the progress of pregi-
nancy, this canal is gradually converted into a part of
that cavity.
  The lower extremity of  the neck of  the uterus is
irreglarly convex  and tumid.   The orifice of the
canal  in it is oval,  and so situated that it divides the
convex surface of  the neck  into  two portions, which
are called the Lips.   The anterior or upper portion
is thicker than the other.
  This extremity of the uterus protrudes into the va-
gina, and is commonly called Os Tincx. As the an-
terior portion or  lip is larger and more tumid than
the posterior, the  vagina extends further beyond the
os tincse on the posterior part than on  tho anterior 
     Fallopian Tubes.—Bound Ligaments    209

              The Fallopian Tubes
  Are two canals, from four to five inches in length,
which proceed between the lamina of the broad liga-
ments, from  the upper  angles of the uterus, in a
transverse direction,  to some distance from the  ute-
rus, when they form  an  angle, and take a direction
downwards towards the ovaries.
  They are formed, for a considerable part of their
extent, by a substance which resembles that of which
the uterus consists,  and are  lined by a membrane
continued from the internal membrane of the uterus.
Their extremities  appear to be composed of mem-
brane, which is rendered florid by the blood vessels
in its texture.  At the commencement their diameters
are extremely small; but they enlarge in theirjpro-
gress.  This enlargement is gradual for the firstnalf,
and afterwards sudden;  the enlarged part is more
membranous than  the small  part, and has a bright
red colour.  The large extremity is loose in the  ca-;
vity of the pelvis, and is not  invested by the lamina
of the broad ligaments.   Near the  termination the
diameter is often contracted ;  after which the mem-
brane which forms the tube  expands into  an open
mouth, the margin of which cousists of fringed pro-
cesses :  this margin is also  oblique,  as respects the
axis of the tube ; and the different;fringed processes
are not all of the same length ; but the longest are
in the middle, and the others regularly diminish on
each side of them:  these  processes  constitute the
Fimbrix of the fallopian tubes.
  The internal  surface of the large  extremities of
these tubes is  extremely vascular; and there  are
some longitudinal fibres of  a red  colour to be seen
on it.
             The Bound Ligaments,
   Which  have already been mentioned, are cords of
  Vol. ti.              ?7 
210         Structure of the Ovaries.

a fibrous structure, with many blood vessels in them.
They arise from the uterus  below the origin of the
fallopian tubes, and proceed  under  the anterior  la-
mina of the broad ligaments  to the abdominal rings,
through which they pass; and then the  fibres and
vessels  are  expanded  upon  the  contiguous  cellular
substance.

                   The Ovaries

   Are  two  bodies of a flattened oval form ;  one of
which is situated  on each side of the uterus on  the
posterior surface xfi the broad ligament, and invested
completely  by a  process of the  posterior  lamen,
which forms a coat, and also a ligament for it. The
size of  this organ  varies in different subjects, but in
a majority of those who are  about  the age of matu-
rity it is between  ten and twelve lines in length.   It
is connected  to the uterus  by a  small ligament, or
bundle of fibres of the same structure with the round
ligaments, which  is not  more than two lines in dia-
meter,  and is included between the lamina of the
broad ligament.
   The process of  the broad ligament forms an exter-
 nal  coat to the ovary ; within this is the proper coat
 of the organ, which is a firm membrane.  This mem-
 brane is so firmly ponnected to the substance of the
 ovary which  it encloses, that it cannot be easily se-
 parated from it.   The  ovary  is of a whitish colour
 and soft texture, and  has  many blood vessels.   In
 virgins of mature age it contains from ten to twenty
 vesicles, formed of a  delicate  membrane, filled with
 a transparent coagulable fluid.   Some of  these vesi-
  cles are situated  so near to the  surface of the ovary
  that they are prominent on its surface;  others  are
  near the  centre.  They are very different  in size;
  the largest  being between  two  and three  lines in 
Arteries of the Uterua.
211
diameter, and others not more than one-third of that
size.
  In women  who have had  children, or in whom
conception  has taken  place, some of these vesicles
are removed; and in their place a cicatrix is found.
  It has  been ascertained,  that during  the sexual
intercourse with males, one of these  vesicles, which
was  protuberant on the surface, is  often ruptured,
and a cavity is found.   A cicatrix  is soon  formed,
where the membrane was ruptured ;  and in the place
occupied by  the vesicle there is a yellow substance
denominated  Corpus Luteum.  This corpus luteum
generally continues until the middle of pregnancy:
it often remains during that state, and for some time
after delivery, but it gradually vanishes.   The cica-
trization continues during life.
  In many cases these  cicatrices correspond with  the
number of conceptions which have taken place ; but
they often  exceed the number of conceptions,  and
they have been found in cases where conception  has
not been known  to have taken place.
  In very old subjects, where conception has never
taken place, the vesicles ^.re either entirely removed,
or small dense tubercles only remain  in their place.

                  The Arteries
  Of the uterus are derived from two very* different
sources; viz. from the spermatic and from  the  hy-
pogastric arteries.
  The spermatic arteries, instead of passing directly
down to the abdominal ring,  proceed  between  the
lamina of the broad liga-mnt, and  send branches to
the ovaries, which may sometimes be traced to  the
vesicles.   They also  send branches  to the fallopian
tubes and to  the  uterus.  Those which are  on  the
opposite sides of the  uterus  anastomose with each
other, and also with the branches of  the hypogastric 
212
Veins of the  Uterus.-
arteries.   There are also  branches of these arteries
in the round ligaments which  accompany them  to
their termination outside of the abdominal ring.
  The principal arteries of the uterus are those de-
rived from the hypogastric, which sends to each side
of it a considerable branch, called the Uterine. This
vessel leaves the hypogastric very near the origin of
the internal pudic, and proceeds to the cervix of the
uterus: it passes between  the lamina of the broad  li-
gaments, and sends branches to the  edge of the ute-
rus, which penetrate its texture.  The branches which
are in the  texture of the  uterus, are very small in-
deed, in young Subjects.  In women who have had
children they are considerably larger;  but during
pregnancy they gradually  enlarge with the growth of
the uterus, and become  very considerable.  These
arteries observe a  serpentine  and peculiarly tortu-
ous course.  Those on the opposite sides anastomose
with each other.                               ,
                    The  Veins

  Of the uterus, like the arteries, form spermatic
and uterine trunks.  The Spermatic Vein  is much
larger than the artery.   It ramifies as in  males, and
forms a very large plexus, which constitutes the cor
pus pampiniforme.   Many of the veins which form
this body, originate  near  the ovary: a considerable
number also come from the fallopian tubes and the
uterus.   The spermatic  vein  and its branches are
greatly enlarged indeed during pregnancy; and it is
said that they are enlarged the same way during the
menstrual discharge.
   The most imporant  veins of  the uterus  are the
branches of the Uterine Veins.  They are extremely
numerous, and form a plexus on the side of the ute-
rus;  from which two or more uterine veins proceed
in the course of the artery, and join the hypogastric. 
       Lymphatics.—Bladder and Urethra.    21. ■

These veins also are  greatly enlarged during  preg-
nancy.
              The Lymphatic  Vessels

  Of the uterus,  and its appendages, are  very nu-
merous.  In the unimpregnated state they are small:
but, during pregnancy, they increase greatly.  They
proceed from the uterus in very different directions.
Some that  accompany the round ligaments go  to the
lymphatic glands of  the groin.   Others  which take
the course  of the uterine blood vessels pass to glands
in the pelvis, and a  third set follows the spermatic.
arteries and veins to the glands on the loins.

                   The Nerves

   Of the ovaries are derived from the renal plexus,
 and those of the uterus and vagina from the  hypo-
 gastric plexus, or the lower portions of the sympa-
 thetic, and the third and  fourth sacral nerves.

                    SECTION IV.

            Of the Bladder and Urethra.
   The situation of the Bladder, as respects the sym-
 phisis pubis, is nearly alike in  both sexes; but that
 part of it which is immediately behind  the insertion
 of the ureters is rather  lower in  males than  in  fe-
 males.   The bottom of the bladder rests upon the
 upper part of the vagina, a thin  stratum of cellular
 substance only intervening: when that  viscus is dis-
 tended it  forms a tumour, which compresses the va-
 gina.
    The ureters are inserted, and the urethra commen-
 ces in the same part of the bladder, in both sexes.
    The length  of the Urethra is between one  and
 two inches.  When the body is in a direct position,
 it is nearly horizontal; but it is slightly curved, with 
214  General Change in the Gravid Uterus.

its  convexity downwards.   It is immediately above
the vagina, and  it passes below'  the body of the cli-
toris.  The external orifice of it is rather more than
an  inch  within  the glans  or head  of  the clitoris.
This orifice is somewhat prominent in the  vagina.
  In the internal or lining membrane of the urethra
there are many orifices of  mucous follicles, and also
longitudinal wrinkles, as in the urethra of  males.
The diameter of the female urethra and its orifice in
the bladder are greater than  they are  in the male.
For this reason it has been supposed, that women are
less liable to calculus of the bladder  than men.*
  The urethra is intimately connected  with the ex-
ternal coat of the vagina, and between them there is
a spongy cellular substance which  makes the  rough
surface of the vagina prominent; so that the urethra
has been supposed, although erroneously,  to  be in-
vested with the prostate.   It is  capable of great ar-
tificial dilatation.

Of the Changes induced in the Uterus in the pro*
              gress of Pregnancy.
  The alteration which takes place in the size of the
uterus during pregnancy is truly great.  About the
conclusion of that period, instead  of the small body
above described, which  is almost solid, the  uterus
forms an  immense sac,  which extends from  the ter-
mination  of the vagina in the pelvis, into the epigas-
tric region ; and from one side of the abdomen to the
other; preserving, however an  ovoid figure.
  This change is so gradual at first,  that the  uterus
does not extend beyond the cavity of the pelvis be-
fore the third  month, although at the end of the se-
venth month it is very near the  epigastric region.
  For the  first  six months the body of the  uterus
  * It has however been asserted that tbey are also less liable to calculi in
the kidneys. 
General Observations.          215
appears principally concerned in the enlargement*:
after this the cervix begins to change, and is gradu-
ally altered  so as  to  compose a portion of the sac,
rather of less thicknes than the  rest of  the  uterus ;
the mouth  being ultimately an  aperture  in a part
which is much thinner than the other portions of the
organ.
   The change which takes place in the texture of
some of the appendages of the uterus is very import-
ant.
   The Broad Ligaments, which seem  particularly
calculated to favour the extension of the uterus, are
necessarily altered by the change in  the size of that
organ, but not entirely done away.   The  portion of
peritoneum of which they are formed must  be very
much enlarged with the growth  of the uterus, as it
continues to cover it.   The Bound  Ligaments  are
much elongated; and they observe a more  straight
course to the abdominal ring.   The Fallopian Tubes
are enlarged;  and instead  of   passing  off laterally
from the  uterus,  they now proceed downwards by
the side of it.   The Ovaries appear rather larger
and more spongy: their relative situation is  necessa-
rily lower.
   The change in  the Uterus itself is particularly in-
teresting.   The great increase of its size  is not at-
tended with any  considerable  diminution of thick-
ness in its  substance ; nor are the arteries much less
convoluted than before pregnancy, as  might have
been expected.   They are greatly enlarged in diam-
eter, and the orifices of the exhalent vessels on  the
internal surface of the uterus are much more percep-
tible.
   The veins are much more enlarged than the arte-
ries, and in some  places appear more  than  half an
inch in diameter.   They are not regularly cylindri- 
216   Peculiarity of the Female Hottentots.
cal, but rather flat.   They anastomose so as to form
an irregular net work.
  The uterus appears much more fibrous and  mus-
cular in the gravid than in the unimpregnated state.
The contractile power of the gravid uterus is not only
proved by the expulsion of its contents, but also  by
very  vigorous  contractions,* which  are occasionally
observed by accoucheurs.

    Although the general effects which result from the par-
      ticular conditions of the  uterus in pregnancy, men-
      struation, &c. evince that the influence of this organ
      upon the whole system is very great, yet it seems pro-"
      bable that the sexual peculiarities of females are espe-
      cially dependent upon the ovaria.
        This sentiment is confirmed by an account of a wo-
      man in whom the ovaria were deficient, which is pub-
      lished in the  London Philosophical Transactions for
      1806, by Mr. C. Pears.  The subject lived to the a|«e*>
      of twenty-nine years.  She ceased to grow after the
      age of ten years, and therefore was not more than four.
      feet six inches in height:  her breadth across the hips,
      was but nine inches, although the  breadth  of the
      shoulders was fourteen.   Her breasts and nipples ne-
      ver enlarged more than they are in the male subjeeCTr
      There was no hair  on the pubes, nor were there any,
      indications of puberty in mind  or body.  She never
      menstruated.  At the age of twenty-nine she died of a
      complaint  in the breast, attended with convulsions.—
      The uterus and os tincae were found not increased'
      beyond their usual siz,e during infancy.  The cavity -
      of the uterus was of the common shape, but its coat*
      were membranous.   The Fallopian Tubes were  per-,
      vious.  ''The Ovaria were so indistinct that they ra-.
      ther shoived the rudiments which ought to have form-4
      ed them, than any part of the natural structure."   '
    Another case, which confirms  the aforesaid sentiment,  •
      is related in one of the French periodical publications./
        It has been long known that a race of savages near
      the Cape of Good Hope were distinguished from thi
      generality of 4heir species by a  peculiarity about the
      pudendum.  An  account  of this structure has beeu 
Peculiarities in the Abdomen of tlie Foetus 217
      given with some precision by Messrs. Peron and Le-
      sueur, in a paper which was read to the National Insti-
      tute of France.  It is a flap or apron, four inches  in
      length, which is united to the external labia near their
      upper angle, and hangs down before the clitoris and
      the external orifice of the parts of generation.   It is
      divided below into two lobes, which covers the orifice.
      It is formed by a soft distensible skin, free from hair,
      which is occasionally corrugated like the scrotum, and
      is rather more florid than the ordinary cutis.*
            The Abdomen of the Foetus.
   The difference between the foetus  and the  adult,
in the cavity of  the abdomen, is very conspicuous  at
the first view.
   The Liver in the foetus is so large that it occupies
a  very considerable part of the abdomen.   Its left
lobe, which  is larger  in proportion  than the  right,
extends far into the left hypochondriac region.
   The Bladder  of urine, when filled, extends from
the cavity of the pelvis a considerable  distance to-
wards the  umbilicus: so that the greatest part of it
is  in  the cavity of the abdomen.  A ligament of a
conical figure extends from the centre of the  upper
part of the bladder to the umbilicus;  with an artery
on each side of it, which is soon  to  be described.
This  ligament, which is in the  situation of the  ura-
chus of the foetus of quadrupeds, is hollow, and thus
frequently  forms a canal,  which  has a  very small
diameter, that communicates with the bladder by an
aperture still smaller, and continues a short distance
from  the bladder towards the umbilicus.  In a few
rare instances this canal has extended  to the umbili-
cus, so that urine has been discharged  through it, but
the ligament is commonly solid there.
 * This paper has not yet been published by the Institute, but it is refer-
red to by M. Cuvier in his Lecons d'Anatomie Comparer, vol. v. page
124—Messrs. Peron and Lesueur were naturalists who accompanied captain
Baudin in his voyage of discovery; the latter has been for some yearn re-
sident in Philadelphia.
   Vol. ?r.               ?S 
21 s   Descent of the Testicle in the Foetus.

  The Stomach appears to  be more curved in the
foetus than in the adult.
  The Great Intestine does not  extend sufficiently
far, beyond the insertion of the  ileon, to  form the
csecum completely.
  The Glandulx Benales are  much larger in pro-
portion in the foetus than in the adult.  The colour
of the fluid they contain is more florid.
  The Kidneys are  lobulatcd.
  The Testicles in  the  foetus  are  found above the
pelvis, in the lumbar region, behind the peritoneum,
until two months before birth.  Thus situated, their
blood vessels and nerves proceed from sourees which
are near them; but the vas deferens, being connected
to the vesiculse seminales by one extremity, is neces-
sarily in  a very different situation from what it is in
the adult: it proceeds from the testicle downwards to
the neck of the bladder.—While each testicle is in
this situation, it is connected with a substance or liga-
ment, called Gubernaculum, of a conical or pyrami-
dical  form, attached to its lower end,  and extends
from  it to the abdominal ring.  This substance is
vascular, and of a fibrous texture: its large extremity
adheres to the testicle, its lower and small extremity
passes through  the abdominal ring, and appears to
terminate in the cellular substance exterior to that
opening, like  the round ligament in females.  The
Gubernaculum, as well as the testicle, is behind the
peritoneum; and the peritoneum adheres to each of
them more firmly than it does to any of the surround-
ing parts.   It seems that, by the contraction of the
Gubernaculum, the testicle is moved down from its
original situation to  the abdominal ring, and through
the abdominal ring  into the scrotum.  The perito-
neum, which adheres firmly to the gubernaculum and
testicle,  and is loosely connected to the other parts,
yields to this operation; and when the testicle has 
       Descent of the  Testicle in the Frdas.    219

arrived near the abdominal ring, a portion of the pe-
ritoneum is protruded a little way before it into the
scrotum; forming a cavity like the finger of a  glove.
The testicle passes down  behind  this process  of the
peritoneum, and is covered by it as it was in the ab-
domen.   Although it appears protruded into the ca-
vity, it is exterior to it, and behind it; and the ves-
sels,  &c. which belong to  the  testiele are  also ex-
terior to it.
  The cavity formed in the scrotum, by this process
of the peritoneum, necessarily communicates with the
cavity of the abdomen at its formation ; but very soon
after the testicle has descended into the scrotum, the
upper part of this cavity is  closed up, while the low-
er part of the process continues unchanged, and con-
stitutes the Tunica Vaginalis Testis.  In some in-
stances the upper part of this process does not close
up,  and the  communication with  the cavity  of the
abdomen continues.    The descent of, the  intestine
into the  cavity  thus circumstanced, constitutes that
species of hernia which is denominated Congenital*
  The most important peculiarities in the abdomen
of the foetus are those connected with the circulation
of the blood.
  The internal iliac or hypogastric arteries are larger
than the external  iliacs.   Their main  trunks are

  * These interesting circumstances respecting the original situation of
the testicle, and its descent into the scrotum, were discovered and  elu-
cidated by Haller, Hunter, Pott, Camper, and several other very respect-
able anatomists and surgeons.  There is, however, a difference of opin-
ion, between some of them, as to the time when the testicle leaves thev
abdomen.  Haller thought  the testicles were seldom in the scrotum at
birth.  Hunter and Camper found them so generally.
  It has been suggested that there are some national peculiarities  in this re-
spect; that  amongst the Hungarians, for example, the testicle? often re-
main above the abdominal ring until near the age of puberty.
  Tin- student will rind an interesting description of the situation of the
testis, and its descent, in the foetus,  in  the " Observations on certain parts
cf the Animal Economy," by Jqhn H'uiter. 
320
Umbilical Vessels.
  continued on each side of the bladder to its fundus;
  and proceed from it, with the ligament,  to the umbi-
  licus ; when they pass out of the abdomen to go along
  the umbilical cord to the  placenta.  These arteries
  are now denominated the  Umbilical, and are very
  considerable in size.   After birth, as there is no cir-
  culation in them, they soon begin to change : the ca-
  vity of  them is gradually obliterated, and they are
  converted into ligaments.   They are exterior to the
  peritoneum, and contained in a duplicature of it.
    A vein also called the Umbilical, which  is much
  larger in diameter than both of the arteries, returns
  from the placenta along the cord, and enters the ca-
  vity of the abdomen at the umbilicus.   It proceeds
  thence,  exterior to the peritoneum, but  in a duplica-
  ture of it called the  Falciform  Ligament, to the
  liver, and enters that viscus  at the great fissure;
  along which it passes to the left branch of the sinus
  of the vena portarum, into which it opens and dis-
  charges the  blood which  flows through it from the
  placenta.  It opens on the anterior side of the branch
  of the vena  portarum, and from the posterior side of
  the branch,  opposite to this opening, proceeds a duct
  or canal, which opens into the left hepatic vein near
  its junction with the vena cava. This communicating
  vessel is called the Ductus, or Canalis  Venosus; to
  distinguish it  from  the duct which passes from the
  pulmonary artery to the aorta, and is called Ductus,
  or  Canalis  Arteriosus.   This venous  duct carries
  some of the blood of the  umbilical vein directly to
,  the vena cava;  but it is  much smaller than the um-
  bilical vein, and of  course a considerable quantity of
  the blood which passes through  the umbilical vein
  must pass through the liver, by the vena portarum,
  before it can enter the cava.
     In some  foetal subjects,  if a probe  of sufficient 
    Object of the Circulation in the Placenta. 221

length be introduced within the  umbilical vein and
pushed forwards, it will  pass  to the heart without
much difficulty or opposition, as if it proceeded along
one continued tube, although  it really passes'from
the umbilical vein across the branch of the vena por-
tarum, and  then through the ductus venosus, and
through a portion of the left hepatic vein,  into the
inferior vena cava.
   If the umbilical vein be injected with  a composi-
tion, which  will be  firm when  cool, it appears to
terminate  in a rounded end, which  is situated in the
transverse fissure of  the liver : the  sinus of the vena
portarum, into which  this vein enters, appears like
two branches going off, one from each side of it, and
the ductus venosus like a branch continuing in the
direction of the main trunk of  the  umbilical vein.
   The umbilical vein, in  its  progress  through the
fissure of  the liver, before it arrives  at the sinus of
the vena portarum, sends off a considerable number
of  branches to each of the lobes of that organ, but
more to the left than to the right lobe.
   After birth, when blood ceases to flow through the
umbilical vein, it is  gradually converted into a liga-
ment ; and  the .venous  duct is also converted into  a
ligament in the same manner.   The vena portarum,
which before appeared very small, when compared
with the  umbilical  vein, now  brings all  the blood
which fills its great sinus, and increases considerably
in size.
   It  has  been ascertained by anatomical investiga-
tion, that the  umbilical arteries above mentioned,
after ramifying minutely in the placenta, communi-
cate with the minute branches of the umbilical vein;
and it is probable that the whole blood carried to the
placenta by these arteries, returns by the umbilical
vein to the foetus.
   It is clearly proved by the effects  of pressure  en 
222  Object of the Circulation in tlie Placenta.


the umbilical cord,  in cases of  delivery by  the feet,

as  well as  by other  similar  circumstances, that this

circulation cannot  be  suspended  for any  length of

time without destroying the life of the  foetus.  From

these  circumstances,  and from  the   florid  colour

which the  blood acquires  by circulating in the pla-

centa, it seems probable that the object of the circu-

lation through that  organ  is  somewhat analogous to

the object of the pulmonary circulation through the

lungs of adults.*


  * During the first four months of pregnancy a very small vesicle, which
does not exceed the size of a pea, is found between the chorion and the amnios,
near the insertion of the umbilical cord into the placenta. It is connected
to the foetus by an artery and a vein, which pass from the abdomen through
the umbilicus, and proceeding along  the cord  to the  placenta, continue
from it to the vesicle.  The artery arises from the mesenteric, and tb$
vein is united to the mesenteric branch of the vena portarum. It is proba-
ble  that these vessels commonly  exist no longer than the«vesicle, vi$
about four months ; but they have been seen by  Haller and Chaussier at
the termination of pregnancy. They are called Omphalo Mesenteric ves-
sels.  The vesicle is denominated the Umbilical Vesicle.
  This  inexplicable structure is delineated in Hunter's Anatomy of the
Gravid Uterus, plate xxxiii. figures v. and vi.; in the Academical Annota-
tions of Albinus, first book, plate i. figure xii.; and also in the Icones fitt-
bryonum Humanorum of Soemmering, figure ii. 
SYSTEM OF  ANATOMY.

                PART IX.
             OF THE BLOOD VESSELS.

  The blood vessels are flexible tubes, of a peculiar
texture, through which blood passes from  the heart
to the different parts of the body, and returns again
from these parts to the heart.  They are to be found,
in varying proportions, in  almost  every part of the
body, and seem to enter into its texture.
.  The tubes which  carry blood from the heart, are
more substantial and more elastic than those through
which it returns to the heart.  They are generally
found empty after death; and, therefore, were called
Arteries by the ancient anatomists,  who supposed
that they earned air, and not  blood.
   The tubes which  return the blood to the heart are
denominated Veins.  They are less substantial and
less elastic than arteries,  and are generally full  of
blood in  the dead subject
   There are two great arteries, from which  all the
other arterial vessels of the body are derived.   They
are very justly compared to the trunks of trees, and
the smaller  vessels to their branches.   One of these
great arteries, called the Aorta, carries blood  to eve-
ry part of the body.   The other great vessel, called
the Pulmonary Artery, carries blood  exclusively to
the lungs. 
224
The Blood vessels in general.
   The veins which correspond to the branches of the
 Aorta, unite to each other, so as to form two  great
 trunks that proceed to the heart.   One of  these
 trunks, coming from the superior parts of the body,
 is called the Superior, or  Descending Vena Cava.
 The other, which comes from the lower parts of the
 body, is  called the  Inferior, or Ascending  Vena
 Cajva.
   The veins which correspond with the branches of
 the  Pulmonary Artery, and return to the heart the
 blood of the lungs, are four in number: two of them
 proceeding from each lung.   They are called Pul-
 monary Veins.
   In many of the veins there are valves, which pre-
 vent the blood  they contain  from moving towards the
 surface and extremities of the body, but  allow it to
 pass towards the heart without impediment.
   From the  construction of  the cavities of the heart,
 and  the position of the valves which are in them; as
 well as the situation of the  valves at the commence-
 ment of the^great arteries, and the above  mentioned
 valves of the veins, it is evident, that when the blood
 circulates,  it must move from the heart, through the
 aorta and its branches, to the different parts of the
 body, and return from these parts through the venae
 cavae, to the  heart;  that, when deposited in the heart
 by the venae cavae, it must proceed through the pul-
 monary artery  to  the lungs, and return from the
 lungs through the pulmonary veins to. the heart, in
 order to pass again from that organ into the aorta.
  It is also certain,  that the blood is forced from the
heart into the arteries, by the contraction of the mus-
cular fibres of which the heart is composed; and that
the blood vessels likewise  perform a part in the cir-
culation, they  propelling the blood which  is  thus
 thrown into them : but their action appears to depend
upon causes of  a complex nature. 
CHAPTER I.
 OF THE  GENERAL  STRUCTURE  AND ARRANGEMENT
              OF THE BLOOD VESSELS.

                     SECTION I.

                 Of the Arteries.

   The arteries are so  much concerned  in  the  im-
 portant function of the circulation of the blood, that
• every circumstance connected with  them is very in-
 teresting.
   They are composed of coats or tunics, which are
 very elastic and strong, and which are also very thick.
 In consequence of the  firmness  of their coats, they
 continue open, after their contents  are discharged,
 like hard  tubes.  They submit  to  great dilatation,
 and elongation, when fluids are forced into them, and
 return to their former dimensions when the distend-
 ing cause is withdrawn.  This  elasticity is particu-
 larly subservient to the circulation of the blood.   It
 admits the artery to distend readily, and receive the
 blood which is thrown  into  it by the contraction  of
 the heart.   It also  produces the contraction of the
 artery; which takes place as soon as the action of the
 heart ceases; and this contraction of the artery neces-
sarily forces the blood  forward,  as  the valves at its
orifice prevent it from returning to the heart.
   The motion of the artery, which  is so  easily per-
ceived by the touch, and  in many instances also by
 the eye, is completely explained by  the discharge of
blood into the  artery  from  the heart, and by the
   Vol. n.              '29 
226
Structure of the Arteries.
elasticity of the vessel, by which it re-acts upon the
blood.   In some cases it is not simply the diameter
of the artery which is enlarged, but a portion of the
vessel  is elongated;  and  this elongation,  by pro-
ducing  a curvature of it, renders its  motion more
visible.
   In the aorta, and  probably in its  large branches,
Elasticity  seems to be the principal cause of the con-
tinuance of the motion which is originally given to
the blood by the heart.  But there are many circum-
stances  connected with  the smaller vessels,  which
evince that they exert a power which is very differ-
ent indeed from elasticity.  Thus the application ef
local stimulants or rubefacients, and of heat, is fol-
lowed by an increase of motion in the arteries of the
parts to which they are applied.  Neither of these.
causes could produce their effect by  the influence of
elasticity:  but  the effect of these and  other  similar
causes is uniformly produced; and a power of inde-
pendent motion,  or Irritability,  is thus proved to
exist in these vessels, and seems essentially necessa-
ry to the circulation  of the blood.
           The Structure of the Arteries
   Is, therefore, a subject of importance, and has re-
ceived  a considerable degree of attention from anato-
mists.
   They are composed of  a  dense elastic substance,
 of a whitish colour.  Their external surface is rough,
 and intimately connected with the cellular membrane,
 which  every where surrounds it in varying quanti-
 ties.   Internally, they are lined with  a thin mem-
 brane, which is very smooth and flexible, and is also
 very elastic.   The  substance which  composes the
 artery, and is situated between  the cellular invest-
 ment and the internal membrane, consists of fibres,
 which are nearly, though not completely, circular, 
Structure of the Arteries.
227
but so arranged as to constitute a cylinder.  These
fibres may be separated  from each  other so  as  to
form lamina,  which have  been considered as differ-
ent coats of the arteries;  but there  is no arrange-
ment of them which composes regular distinct strata.
The coats of  arteries may, therefore, be  separated
into a greater or smaller  number of lamina, accord-
ing to the thickness of these lamina.
  The fibres which compose these lamina appear  to
be united to  each  other in a way which readily al-
lows of their separation,  at the same time that they
form a firm texture.  Although arteries thus appear
essentially different from  muscles in their hardness
and their elasticity, as well as in their general tex-
ture, they are  considered,  by a great majority of
anatomists, as partaking  more or less of a muscular
structure.
   In the human subject their structure is  very diffi-
cult of demonstration,  and great differences exist in
the accounts which are given of it, even by  anato-
mists who agree  in the general sentiment  that the
arteries are muscular.
   Thus Haller believed  that muscular  fibres were
 most abundant in the large arteries, while J. Hunter
 thought the  reverse.
   Hunter appears to have investigated this subject
 with  great  attention, and supposed  the muscular
 substance, in the composition of arteries,  to be inte-
 rior, and the elastic matter exterior; that in large
 arteries this muscular  substance  is very  small  in
 quantity,  and gradually increases in proportion as
 the artery diminishes in size.  He however observes,
 that he never could discover the direction  of the
 muscular fibres.*
    When  the great  talents  of Mr. Hunter  as an

     * Treatise on the Blood, fcc. Vol. I. p. 113.   Bradford's edition. 
328 Question respecting the muscularity of Arteries.

anatomist,  are considered,  this circumstance cannot
fail to excite a  belief that the  existence  of  these
fibres is not certain :  and if to this be added the fact,
that even the red coloured substance of the arteries
is elastic, and in  that respect different from muscu-
lar substance, the reasons  for  doubting must be  in-
creased.
  Bichat appears to have entertained very strong
doubts on the subject; but he stands almost alone;
for a large number both of the preceding and cotem-
porary anatomists, seem  to have adopted the  senti-
ment, that the arteries have a muscular structure.
   The  student  of anatomy can very easily examin*
this subject himself,  by separating the coats of arte-
ries into different lamina; and by viewing the  edges
of the transverse and  longitudinal sections of those
vessels.  While  thus engaged with this question, he
will read with great  advantage what  has  been writ-
ten upon it by Mr. Hunter,  in his Treatise on  the
Blood, &c.   See chapter second, section  3.  Bichat
ought also to be read  upon  this subject, which he
has discussed in  his  Anatomie Generate—Systeme
Vasculaire a Sang Bogue, article  Troisieme, &c. and
also in his  Traite des Membranes, article Sixieme*
   The belief of  the  irritability of arteries does not
however, rest upon the appearance of their fibres.
   1.  It  is  asserted  by very respectable  authors,*
that they have been  made to contract by the appli-
cation of mechanical  and of chemical irritation, and
also of the electric and galvanic power.
   2.  A partial  or local  action  of arteries  is often
produced by the local  application of heat and rube-
facients, as has been  already observed.


  * See Soemmering on the structure of the Human Body, Vol IV. Ger-
man edition. Dr. Jones on the Process employed by nature for suppressing
If$morrhage, &c. 
    Proofs of the Irritability of the Arteries. 229

  3. Arterial action is often suspended in a particu-
lar part by the application of cold.   It has also been
observed that the arteries have for a short time ceas-
ed to pulsate in cases of extreme contusion and lace-
ration of the limbs.*
  4. When arteries are divided transversely in living
animals, they often contract so as to close completely
the orifice  made by the division.
  5. In a horse bled to death, it was ascertained by
Mr. Hunter, that the transverse diameter of the ar-
teries was diminished  to a degree that could not be
explained by  their elasticity.  He  also found that,
after  death, the  arteries, especially those  of the
smaller size, are generally  in a  state of contraction,
which is greater than can be explained by their elas-
ticity : for if they are distended mechanically, they
do not contract again to their former size,  but conti-
nue of a larger diameter than they were before the
distention; although their elasticity may act so as to
restore a very considerable degree of the contraction
observed at death.
  The contraction, which is thus done away by dis-
tention, Mr. Hunter supposed to have been produced
by muscular fibres: for, if it  had been dependent on
elasticity, it must have re-appeared when the distend-
ing power  was withdrawn.
  It therefore seems certain, that the arteries have a
power of contraction  different  from that which de-
pends  upon elasticity;  but  whether  this depends
upon muscular fibres superadded to them, or upon
an irritable quality in the ordinary clastic  fibres of
blood vessels,  is  a question which is  not  perhaps
completely decided.

  * This local suspension of arterial motion by cold, &c. applied locally.
is very difficult to explain; as the action of the heart and the elasticity of
the arteries appear sufficient to account for the pulsation of the large ar- 
230   General Observations on the Arteries.

   The motion of the blood in the arteries appears to
depend,
   1st, Upon the impulse given to it by the action of
the heart.
   2dly,  Upon the elasticity of the arteries,  in conse-
quence of which they first give way to the  blood
impelled into them, and then re-act upon it; and
   3dly,  Upon the power of contraction in  the arte-
ries, or their irritability.
   In the larger arteries the blood seems  to  move as
it would through an inanimate elastic tube,  in conse-
quence of  the impulse given by the heart,  and kept
up by the arteries themselves.  In  the smaller ves-
sels it seems probable that the motion of the blood
depends in a considerable degree upon the contrac-
tion which arises from their irritability.
   The obvious effect of the elasticity of  the arteries
is to resist distention and elongation, and to contract
the artery to its natural state, when the distending
or elongating cause ceases to act.  But it must  also
resist the contraction induced by the muscular fibres,
and restore the artery to its natural size when  the
muscular fibres cease to act after contracting it, as
has been observed by Mr. Hunter.
   It seems probable that all the fibres of which  the
artery consists are nearly but not completely circular,
for it is not certain  that there are  any longitudinal
fibres in the structure of an artery.
   The internal coat of these vessels  is  very smooth,
but extremely dense and firm; and  seems to be ren-
dered  moist and flexible by an exudation on its sur-
face.   It adheres very closely to the contiguous fibres
of the coat exterior to it, but may be very readily
peeled off from them.   It is of a whitish colour,
and, like the fibrous structure of the artery, is very
elastic.  Like that substance also  it is easily torn or
broken, and when  ligatures  have been  applied to 
       General Observations on the Arteries.   231

arteries, it has often been observed  that the fibrous
structure and the internal coat have been separated
while this external  cellular coat  has remained en-
tire.
  The arteries are supplied with their proper blood
vessels and lymphatics.  It is to  be observed, that
the blood vessels are not derived from the artery on
which they run, but from the contiguous vessels.
  These vessels have  nerves  also, which are rather
small in size, when compared with those which  go to
other parts.
  Arteries appear to have a cylindrical form, for no
diminution of diameter is observable in those portions
of them which send off no  ramifications.
  When  an  artery  ramifies the area of the differ-
ent branches exceeds  considerably that of  the  main
trunk. Upon this  principle the aorta and its branches
have been compared  to a  cone, the basis  of which
is formed  by the branches, and  the apex by the
trunk.*
  The transverse  section of an artery is circular.
  There are no valves in  the  arteries, except  those
of the orifices of the aorta and the pulmonary artery,
at the heart.  The  valves  of the pulmonary artery
have been described in the 51st page of this volume,
and those of the aorta have an exact resemblance to
them, but are rather larger.
  The course of the arteries throughout the body is
obviously calculated  to  prevent their exposure to
pressure, or to great extension from the flexure of the
articulations  by which they pass.   With this  view
they sometimes proceed in  a winding direction; ^nd
when they pass over parts which are subject to great
distention or enlargement, as the  cheeks, they  often

  * According to Brussiere tiie relation of the branches of the aorta to its
trunk is as 25 to 16; Helvetius reckons the orifice of the aorta in compa-
rison with its branches as 61 to 71.  Lasaus.—Ed. 
    232   General Observations on the Arteries.

    meander;  and,  therefore,  their  length may be in-
    creased by straightening, without stretching them.
      Their course appears  sometimes to  have  been
    calculated  to lessen the force of the blood, as is  the
    case with the Internal Carotid and the Vertebral^ ar-
    teries.
      In the trunk of the body the branches of arteries
    generally form obtuse angles with  the  trunks from
    which they proceed.  In  the limbs these angles  are
    acute.
      The communication of arteries with each  other is
    termed Anastomosis. In some instances, two branches
    which proceed  in  a  course  nearly similar,  unite
    with an acute  angle, and form one common trunk.—
    Sometimes, a  transverse branch runs from one to the
    other, so  as to  form a  right angle with  each.   In
    other cases,  the two anastomosing branches form an
    arch, or portion of a circle, from which many branches
    go off.
      By successive ramifications, arteries gradually di-
    minish in size, until they are finally extremely small.
      The smallest arteries do not carry red blood, their
    diameters being smaller  than those of the red parti-
    cles of that fluid, the serous  or aqueous part of the
    blood can,  therefore, only  pass through them.
      Many of the arteries  which carry red blood,  and
    of  the last  mentioned serous arteries terminate in
    veins, which are in some  respects,  a continuation of
    the tube reflected backwards.*

      * Malpighi and Leeuwenhoek declare, that by the aid of a microscope,
#   they have seen arteries terminating  in the veins.  Haller advances for-
    mally his own experience  in support of his assertion.  Other anatomists
    have seen, that in blowing into an artery, the air passed into the corres-
    ponding veins.   Nevertheless, Duverney and some others say, that a
    particular substance is interposed between the extremities of these ves-
    sels.   Ruysch in his Thesauras Anatomicus, VI. No. 73, says, in repletione
    arteriarum, replentur et plurimum quosque vense, et vice versa, ita ut im-
    possible videatur precise dicere quomodo res se  habeat.   Discours sur
    Z'Anat—Ed. 
        General Observations on the Veins.    233

  They likewise terminate in exhalent vessels, which
open upon the external surface, and upon the various
internal surfaces of the body.  The secretory vessels
of glands are likewise the termination of many arte-
ries.

                    SECTION II.


                 , Of the Veins.

  These tubes, which return to the heart the blood
carried from it by the  arteries, are  more  numerous
than the arteries, and often are larger in diameter.
  They generally accompany the arteries, and very
often two veins are found with one artery.
  In addition to  these last mentioned  veins, which
may be called deep-seated, there are many subcuta-
neous veins which appear on almost every part of
the surface of the body.
  The  capacity of all the  veins is therefore much
greater than that of all the arteries.
  Those subcutaneous veins, which  are of consider-
able size, communicate very freely with each other,
and also with the deep-seated veins.
  The trunks of  the veins, in those places where no
branches go  off,  are generally cylindrical.   There
are, however, some exceptions, in which  these  ves-
sels are irregularly dilated, as sometimes happens in
the case of the internal  jugular vein.   It  is how-
ever, not easy to  determine from the appearance of
veins injected after death, respecting their situation
during life, as their coats are very yielding; and it
is very probable  that they are, therefore, preterna-
turally dilated by the injection.
   Veins, directly or indirectly,  originate from  the
termination of arteries:  but they do not pulsate as
the arteries do,  because the impulse  given to  the
  Vol. n.              30 
234
Coats of Veins.
blood by the heart is very much diminished in con-
sequence of the great diminution of the  size of the
vessels  through which the blood has passed.
   In some  cases,  however,  when blood  flows from
an opened vein; the extent of its projection is alter-
nately  increased  and diminished,  in  quick succes-
sion, as if it were influenced by the pulsation  of the
heart:
   The  Coats of Veins differ considerably from those
of Arteries,—for they are thinner, and so much less
firm, that veins, unlike arteries, collapse  when they
are empty.
   They  consist of  a  dense elastic substance, the
fibres of  which are much less distinct  than those of
arteries,  but some of them are to be seen in a longi-
tudinal direction.   These fibres can be made to con-
tract by local irritation ;  for if a vein be laid bait
in a living animal, and then punctured, it will often
contract so as  to diminish  its diameter  very  consi-
derably, although  no blood shall have escaped from
the punctures.
   Next to the elastic  substance is the internal coat,
which is smooth and polished.  It is separated from
the substance exterior to it with difficulty, although
it may  be taken from it very easily in the'vena cava.
   This internal coat is  more ostensible than the in-
ternal coat of arteries, and is not, like the latter, dis-
posed to ossification.   It  is  frequently so arranged
as to form valves,  which are plaits or  folds, of a se-
milunar form, that project from the surfaces into the
cavities of these vessels.*
   Two of these valves are generally placed opposite

  * The valves of the veins were first described by Charles Etienne of Pa-
ns in 1546.  In 1547, Amatus, a Portuguese, saw at Ferrara those at the
mouth of the vena azygos.  Sylvius of Paris announced them about the
same time in the jugular, brachial and crural veins-  Fabricus ab Aqua-
pendente claims the discovery for himself in 1574  Lassus.—Ed. 
        Colour of the Blood in the Veins.     ::i.')

to each other; and, when raised up, they form a sep-
tum in the cylindrical cavity of the vessel.  The sep-
tum, thus composed, is concave towards the heart.
   The valves have a great effect in preventing the
contents  of  the veins from  moving in a retrograde
course: they, therefore necessarily modify the effects
of lateral pressure, in such a manner, that it propels
the blood forward, or to the heart.
   These valves are generally found in the veins of
the muscular parts of the body, especially in those of
the extremities.   They are  not found in those veins
which are in the cavities of  the body, nor in the in-
ternal jugulars.—They are  placed  at unequal  dis-
tances from each other.
   The coats of the veins are somewhat transparent;
and, therefore, those veins which are subcutaneous
have  a bluish aspect, which  is derived from the co-
lour of the blood they contain.
   The colour of the blood in the veins  is  different
from  that in the arteries, being of a darker red.
   The situation and arrangement of the large trunks
of veins  is much alike in different subjects; but the
branches, especially those which are  subcutaneous,
are very variable in their situations. 
CHAPTER II.
A PARTICULAR ACCOUNT OF THE DISTRIBUTION OF THE
                    ARTERIES.

                    SECTION I.

                Of the AOBTA,*

   Or the Great Trunk of the Arterial System,

  When the heart is in its natural position, the right
ventricle is nearly anterior to the left, and, therefore,
the aorta, where it originates from the left ventri-
cle, is behind the pulmonary artery, and covered by
it.  Its first direction is so oblique towards the right
side of the body, that it crosses the pulmonary artery
behind, and appears on the right side of it.   It has
scarcely assumed this position before its course alters,
for it then  proceeds obliquely backwards, and to the
left; so as to form a  large curve or arch, which ex-
tends to the left of the spine.
  The position of this curve  or arch is so oblique,
with respect to the body, that the  cord or diameter
of it, if it were extended anteriorly and posteriorly,
would strike the cartilage of the second or third right
rib about the middle of its length,  and the  left rib
near the head.   In  consequence of this  position  of
the curve,  the aorta crosses over the right branch
of the pulmonary artery, and the left branch of the
windpipe:  and assumes a situation, in front, and  to
the left of the third  dorsal vertebra: from this situa-
tion it proceeds downwards; in front, but rather on
* This name was given by Aristotle.—Ed. 
SituationoftheAortain the Thoraxfy Abdomen. 237

the left side of the spine, and  in  contact with that
column.
  The aorta, as well as the Pulmonary Artery,
for a small  distance from the heart, is  invested by
the pericardium; and, when that sac is  opened, ap-
pears to be contained in it.
  After crossing the right branch of the Pulmonary
Artery, a ligament is inserted into it, which proceeds
from the main trunk of the Pulmonary artery at its
division: this  ligament was the Canalis Arteriosus
in the foetus.
  As the aorta proceeds  down  the spine, it is si-
tuated between the two lamina of the mediastinum,
and in contact with the left  lamen, through which  it
may be seen.   It deseends between the  crura of the
diaphragm, in  a  vacuity which is sufficiently large
to admit of its passage without pressure from the
surrounding parts, and is still in contact with the
anterior surface of the spine, but rather to the left  of
the middle of it.   It continues this course along the
spine until it arrives  at the cartilaginous substance
between the fourth and fifth lumbar vertebrae, when
it divides  into two great  branches  of equal size,
which form an acute angle with each  other.  These
are  denominated the  common, or primitive iliac
Arteries.
   From the aorta in this course are sent off the ar-
teries which are distributed to all  the parts of the
body for their nourishment and animation.
   From the curve  proceed the great branches which
supply the heart, the  head, the  upper extremities,
and part of the thorax.  Between the curve and the
great primitive iliac  arteries, the aorta  sends  off
those branches which supply the viscera contained
in the cavities of the thorax and abdomen,* and part
  * It ought to be observed here, that the viscera iu the lower part of the
pelviB receive  some branches from the internal ili»«- artrrie« 
 238 Origin of the Subclavian and Carotid Arteries.

 of the trunk of the body.  The great ILIAC branches
 of the AORTA are divided into smaller arteries,
 which supply the whole of the lower extremities and
 some of the viscera of the pelvis.

                    SECTION II.

 Of the Branches which go off from the arch of the
                    AORTA.

  The proper arteries of the heart, denominated co-
 ronary arteries, proceed  from the  aorta  so
 near to the heart that their orifices are covered by
 the semilunar valves, when those valves are pressed
 against the sides of  the artery.   These arteries havf|
 been  described  in  the  account of the heart.—See
 p. 50.
  The arteries of the head and of the upper extremir
 ties proceed from the upper part of the curve in the
 following manner.
  A large trunk, called arteria innominata, goes
 off  first.  This is more  than sixteen lines in length
 when it divides into two branches:  one of  which
 supplies the right side of the head, and is denomi-
 nated the right carotid : the other proceeds to the
 right  arm, and from its course under the clavicle, is
 called, at first, the right subclavian.  Almost in
 contact with the first trunk, another artery goes off,
 which proceeds to the left side of the head, and  is
 called the left carotid.  Very near to this, arises
 the third artery, which proceeds to the left arm, and is
denominated the left subclavian. From these great
 branches originate the blood vessels, which are spent
upon the head and neck and the upper extremities.
  As these arteries arise from the  curve of the
aorta, they are situated obliquely with respect  to
each other.   The arteria innominata is not only 
  Situation of the Common Carotid Arteries. 239

to the right, but it is also anterior to the two others:
and the left subclavian is posterior, as well as to
the  left of the left carotid  and the arteria in-
nominata.

         THE CAROTID  ARTERIES.

  The two carotid arteries above mentioned have
been denominated common carotids, to distinguish
them from their first  ramifications which are  called
internal and external carotids.

         THE COMMON CAROTIDS

Proceed towards the head on each side of the trachea:
at first they diverge, but they soon become  nearly
parallel to each other, and continue so until they have
ascended as high as the upper edge of the thyroid
cartilage, when they divide into the internal and
external carotids.
  These arteries are at first very near each  other,
and rather  in front  of the trachea; they gradually
diverge and pass backwards  and outwards on the
sides of it, and of the cesophagus, until they have ar-
rived at the larynx.   In the lower part of the neck
they are covered by  the sterno mastoidei, the sterno
hyoidei, and  thyroidei, as well as by the platysma
myoidei muscles.   Above, their situation is more su-
perficial  ; and they are immediately under»the pla-
tysma myoides.
  On the inside, they are very near the trachea and
larynx, and the cesophagus; on the outside,  and ra-
ther anterior to them, are the internal jugular veins;
and behind, on each  side, are two important  nerves
called the intercostal and the par vagum.   These
blood vessels  and nerves are surrounded by absor-
bent vessels. 
240         External Carotid Artery.
   The  common  carotid  arteries send off no
branches from their origin to their bifurcation ; and
they appear to preserve the same diameter through-
out their whole extent.   In some  few instances the
right carotid has been found  larger  than the left.
The external and internal branches into which they
divide,  are nearly equal  in the adult; but it is sup-
posed that the internal is the largest during infancy.
The relative position of these branches is also differ-
ent at the commencement from what it is afterwards.
The internal carotid forms a curve which pro-
jects outwardly, so as to be exterior to the exter-
nal carotid, while this last proceeds upwards, and
rather backwards.
  THE EXTEBNAL CABOTID ARTEBY
May be considered as extending from its commence-
ment, which is on a line with the superior margin of
the thyroid  cartilage, to the neck of  the condyle of
the lower jaw, or near it.
   At first it  is superficial;  but as it proceeds up-
wards it  becomes deep-seated; and passing under
the digastric and stylo-hyoidei muscles, and the ninth
pair of  nerves, is covered by the Parotid Gland.
After this, it again becomes superficial; for the tem-
poral  artery, which may be regarded as the contin-
uation of the external carotid, passes over the zygo-
matic process of the temporal bone.
   As the  external carotid  supplies with blood the
upper part of the neck  and throat, the exterior of
the head and face, and the inside of the mouth and
nose; its  branches must necessarily  be numerous,
and must  pass in very various directions.
   Thus, soon after its commencement, it sends off, in
an anterior direction, three large branches; viz. to the
upper part of the neck, to the parts within the lower
jaw, and  to the cheeks and lips.  These are deno- 
       External Carotid and its Branches.    241

minated, the superior thyroid, the  sublingual,
and the facial. It then semis off to the back of the
head one which is  called the occipital ; and, as it
proceed^ upwards near the condyle of the lower jaw,
another which passes internally, behind the  jaw, to
the deep-seated parts in that direction.  After this,
it forms the temporal artery, which supplies the fore-
head and central parts of the cranium.  Besides these
larger branches, the external  carotid sends of two
which are smaller ;  one from near the origin  of the
sublingual artery, which is spent principally upon the
pharynx and fauces, and is called the inferior pha-
ryngeal : and another,  while it is involved with the
parotid gland, which  goes to the ear; and is there-
fore called posterior auris.
  These  arteries are distributed in  the following
manner:

       1. The superior thyroid branch

Comes off very near the root of the  external carotid,
and sometimes from the common trunk ; it runs ob-
liquely downwards  and  forwards, in  a  meandering
course, to the thyroid gland, where it is spent.  Dui>
ing this  course it sends off one hranch to the parts
contiguous to the os  hyoides ; another to the neigh-
bourhood  of the larynx : and  a  third branch, which
may be termed laryngeal,  that passes with a small
nerve derived from the laryngeal branch of the par
vagum, either  between the os  hyoides and thyroid
cartilage,  or the thyroid and cricoid  cartilages, to
the interior muscles of the larynx ; and finally re-
turns again to  terminate externally.
   While in the thyroid gland  this artery anastomo-
ses with the inferior thyroid, and also with its fellow
on the opposite side.
   Vol. h.      .      31 
£42    Branches of the External Carotid.

    2. The lingual, or sublingual branch,

Goes off  above the last mentioned  artery,  and very
near it;  but in a very different direction, for it runs     )
upwards and forwards, to the tongue.  In this course
it crosses obliquely the os  hyoides, and is commonly
within the hyoglossus muscle.  It gives off branches1    i
to the middle constrictors of the pharynx, and to the
muscles contiguous to the tongue.  It also sends off a
branch which penetrates to the  back of the tongue,   ,4
which is called,' from its situation, Dorsalis Lingua
At the anterior margin of the  hyoglossus  muscle it
divides into two branches, one of which passes to the
sublingual  gland and the adjacent.parts, and is thence    j
called Sublingual; while the other branch,  the Rani".    ^
na, passes by the side of  the genio glossus muscle to
the apex of the tongue,                             i
     3. The facial or external maxillary,       1
Runs obliquely upwards and forwards under the ninth    . 1
pair of nerves, the stylo hyoideus muscle and the ten-  ^ j
don of the digastric, across the lower jaw and cheefcjj^M
towards  the inner corner of the eye, in a serpentioSH
course.  Before it crosses the jaw it sends off severe    J
branches, viz. to the pharynx, the tonsils, the inferior    fl
maxillary gland and the parts contiguous to  it.  It also   Jj
sends a branch towards the chin,  which passes between  '«
the mylo-hyoideus, the anterior belly of the digastric,  ^j
and the  margin of the lower jaw: and some of its    |
branches continue to  the muscles of the under lip.   -J
*This branch is called Jihe  Submental.                 M
   This artery then passes round the basis or inferior   1
edge of  the lower jaw, very near the anterior margin   j
of the masseter muscle,  and is so superficial that its   I
pulsations  can be readily perceived.  After this turn,    j|
its course is obliquely upwards and forwards.   Neav
the basis of the jaw it sends off  a branch to f>.^ mas-   1 
        Bra]telle* of the External Cajoiia.    Mii

seter, which anastomoses with small branches from
the temporal;  and another which passes superficially
to the under lip and contiguous parts of the cheeks,
This last is called the Inferior Labial.
  After the artery has  passed as high as the teeth in
the lower jaw, it divides  into two branches ; Which
go, one to the  under, and the other to the upper lip;
that to the upper lip is largest.  These branches are
called Coronary.
   The Coronary Artery of the lower lip passes under
the muscles called Depressor Anguli  Oris,  and Or-
bicularis  Oris,  into the  substance of the  lip,  and
anastomoses with its fellow of the opposite side.
   The  Coronary Artery of the upper lip passes un-
der the zygomaticus major and  the orbicularis,  and
very near the margin of-the upper lip internally.   It
also anastomoses freely with its. fellow on the  oppo-
site side.   These anastomoses are frequently so con-
siderable  that the  arteries  on one side can be well
filled by injecting those of the other.  The coronary
branches, as well as the  main trunk of the facial ar-
tery, observe a serpentine or tortuous course; in con-
sequence of which they  admit  of the motions of the
cheeks and lips, which  they would greatly impede
if they were straight.
   From the upper coronary artery a branch conti-
nues  in the direction o.f the main trunk of the fa-
cial artery, by the side  of the nose, which extends
upwards, sending off small  branches in its course,
and finally terminates about the internal angle of the
eye and the forehead.

          4.  The inferior pharyngeal,

Is a very small artery ; it rises  posteriorly from  the
external fcarotid, opposite to the origin of the sublin-
 gual,  and passes  upwards to  the  Jaasis of the  era- 
244   Branches of the External Carotid.
nium.   In this course it sends several branches to the
pharynx, and to the deep-seated parts immediately
contiguous.
  It also sends  branches to the first ganglion of the
intercostal nerve, to the par vagum, and to the'lym-
phatic glands of the neck ;  and finally it  enters the
cavity of the cranium by  the  posterior  foramen la-
cerum.
  In some cases it also sends a small branch through
the anterior foramen lacerum.
            5. The occipital artery

Arises from  the posterior  side of the external caro-
tid,  nearly  opposite  to the  facial,  but  sometimes
higher up ;  it ascends obliquely,  and  passes to the
back  part of the  cranium,  between the  transverse
process  of the atlas and the mastoid process of the
temporal bone.
  In this course it passes over the internal jugular.
vein and the eighth pair of nerves,  and  under the
posterior part of the  digastric muscle; it lies very
near to  the base of the mastoid  process, and under
the muscles  which  are inserted into it.   After
emerging from  these  muscles,  it runs superficially
upon  the occiput, dividing into branches  which ex-
.i.j*:l to  those of  the temporal artery.
  The occipital artery sends off  branches to the
mi.sch-s which are contiguous to it, and to  the glands
of the neck.
  It  also gives  off the  following branches:   one
called the  Meningeal, which  passes  through the
posterior foramen  lacerum to the under  and  back
part of  the dura mater : one to the exterior parts of
the ear:  another which passes downwards, and is
spent upon the complexus, trachelo mastoideus, and
other muscles of the neck :  and several smaller ar-
teries.    • 
         Branches of  the External Carotid.     245
                                   V.
   The artery next to be described, is sbmetimes sent
 off by the occipital artery.

 6. The posterior  auricular, or stylo mastoid
                      ARTERY,

 When it arises from  the external carotid,  comes off
 posteriorly from  the artery, where it is involved with
 the  parotid gland, and passes backwards between the
 meatus auditorius externus and  the mastoid process.
 It then ascends,  in a  curved direction, and termin-
 ates behind the ear.
   In this  course it sends off small branches  to the
 parotid gland, and to the  digastric and sterno mas-
 toid  muscles.   Sometimes a distinct branch,  which
 is particularly visible in children, passes through an
.aperture in the meatus auditorius  externus,  and  is
 spent on its internal surface.
   It also  sends  off a branch which  enters into the
 Stylo Mastoid Foramen, and supplies small  vessels
 to the membrana tympani and  the lining  membrane
 of the cavity of the  tympanum; to the mastoid celis;
 to the muscle of the stapes, and to the external semi-
 circular canal.   One of these vessels anastomoses,  in
 the  upper and posterior part of  the cavity of the tym-
 panum, with a small twig derived from the artery of
 the  dura mater.  When it has arrived behind the
 ear, the Posterior Auricular Artery terminates upon
 the  external ear and the parts contiguous to it.

      7. The INTERNAL MAXILLARY ARTERY *
 Arises from the external carotid under  the parotid
 gland, at a little distance below the neck of the con-

   The general situation of this artery, and the distribution of several of
 its most important branches, cannot be understood without a knowledge of
 the bones through which they pass.  The student of surgery will therefore
 derive benefit from a re-examination of these bones, and of the zygomatic
 fossa, &c. when he studies this artery.  (See Vol. I. page 73.V-He ougn* 
 M6      The Internal Maxillary Artery.

 dyloid process of the lower jaw, and extends to the
 bottom of the zygomatic fossa:  varying its direction
 in its  course.  It is rather larger than the temporal,
   a.  It first sends off one or two small branches to
 the ear, and a twig which penetrates into the cavity
 of the tympanum by  the glenoid fissure.
   b.  It also sends off a small artery called the Les-
 ser  Meningeal, which  passes  upwards, and  after
 giving branches to the external pterygoid and the
 muscles of the palate, passes  through  the foramen
 ovale, and is spent  upon  the dura mater about the
 sella turcica.
   c  It then sends off one of its largest  branches, the
 G?-cat or Middle Artery of the Dura Mater, which
 passes in a straight direction to  the foramen spinale,
 by which it  enters into the cavity of the cranium.
   This  artery ramifies largely on the dura  mater,
 and makes those aborescent impressions which are
 so visible in  the parietal bone.   It generally  divides
 into two great branches:  the anterior,  which is the
 largest, passes over the anterior and inferior angle of
 the parietal  bone: the posterior branch soon  divides
 into many ramifications, which are extended  lateral-
 ly and posteriorly.              .
   It furnishes the twig which passes to  the  ear by
 the  hiatus of  Fallopius,  and anastomoses with the
 small branches of the stylo mastoid artery.
   It  also supplies some  other  small vessels which
 pass to the cavity of the tympanum by small  forami-
 na  near the junction of the squamous and petrous
 portions of the temporal bone.
   d.  The next branch sent off by the internal  max-
 illary leaves  it about an inch from its origin,  and is

 to be well acquainted with this subject, if he should undertake the man-
 agement of necrosis of the  jaw bones ; or of those fungous tumours,
 which sometimes  originate in the antrum maxilfare ; «ts well as of  several
-rtber complaint" 
         The Inttrnal Maxillary Artery.      247

called the Inferior Maxillary,  It  passes between
the internal pterygoid muscle and the bone, and after
giving small branches to the contiguous muscles, en-
ters the canal in the lower jaw, in company with the
nerve.  This canal has a  very free communication
with the cellular structure of the jaw, and the artery
in its progress along it sends branches to the respective
teeth  and the bone.   At the anterior maxillary fora-
men, this artery sends off a considerable branch, which
passes out and  anastomoses with tfye vessels on the
ehin,  while another branch passes forward and sup-
plies the canine and incisor teeth and the bone con-
tiguous  to them.
  Sometimes the  inferior  maxillary artery divides
into two branches  before it has arrived at this fora-
men.   In this case, one of the arteries passes  out of
the foramen, while the other continues to the sym -
phisis.
   e.  Two branches pass off to the temporal muscle,
which originate at a small distance from each other :
one of  them passes  upwards  on the tendon  of the
temporal muscle; the  other arises near the tuberosity
of the upper maxillary bone: they are called the ex-
terior* deep, and the interior  deep  temporal artery.
They are both  spent  upon the temporal muscle; but
the interior branch sends a small twig into the orbit
of the eye.
   r.  There are some small branches which pass  to
the Pterygoid Muscles and to the Masseter,  which
arise  either from the internal maxillary artery, or from
the anterior deep temporal.  They are generally small,
and often irregular.
   c.  An artery, particularly  appropriated  to the
cheek,  perforates  the buccinator muscle  from  within
outwards, and generally terminates on the buccinator.,
the zygomaticus major and the muscles of the lips.
 Hiis Artery of the Cheek is  very  irregular  in ite 
£48       The Internal Maxillary Artery.
 origin, sometimes arising from the internal maxillary,
 sometimes from  the  deep temporal, and sometimes
 from the suborbitary, or from the alveolar artery, to
 be immediately described.
   h. The Alveolar Artery, or  the  Artery of  the
 Upper Jaiv, arises generally from the internal maxil-
 lary, but sometimes from one of its branches.  It winds
 round the  tuberosity of the upper jaw, and sends
 branches to the buceinator muscle,  to  the  bone and
 the gums, to the  antrum highmorianum, and some of
 the molar teeth:" and also to  the teeth generally, by
 means of a  canal which is analogous to that of  the
 lower jaw.
   i. The Infra orbitar Artery arises from the inter-
 nal maxillary in the zygomatic fossa, and soon enters
 the infra orbitary canal, through which  it passes to
 the  face, and  emerges below the  orbit of  the eye,
 Supplying the  muscles  in the vicinity, and anasto-
 inosing with the  small  ramifications of the  two  last
 described arteries, and  also of the  facial artery and
 the ophthalmic.
   This artery in  its course sends off small  twigs to
 the periosteum, the adipose membrane, and the mus-
 cles in the inferior part of the orbit, and also to  the
 great maxillary sinus or antrum highmorianum, and
 to the canine and incisor teeth.
   j.  The Palato Maxillary, or Superior Palatine
 Artery, arises also in the  zygomatic fossa, and, de-
 scending behind the upper maxillary bone, enters the
 posterior palatine canal.    It  generally  forms  two
 branches,  the  largest  of  which advances forward,
 Supplying the palate and  gums, and  finally sends a
 twig through the foramen incisivum to the nose, while
 the posterior branch, which is much smaller, supplies
the velum pendulum palati.
   k. ThePterygo Palatine, or Superior Pharnygeal,
is a Small vessel; which  sometimes arises from the 
                Temporal Artery.             24'J

artery next to be mentioned.   It is  spent upon the
upper  part  of  the pharynx, and  a  branch passes
through the  pterygo palatine foramen, which is spent
upon the arch of the palate and the contiguous parts.
  L. The internal  maxillary at length  termi-
nates in the  Spheno-Palatine, or Large Nasal Ar-
tery, which passes through the spheno-palatine fora-
men to the  back part of  the nose.   This artery
sometimes separates into two branches before it en-
ters the  foramen;  sometimes it enters singly, and
divides into  two branches soon after; one of  them is
spread upon the septum, and the other upon  the ex-
ternal side of the nose; each of these branches rami-
fies very minutely upon the Schneiderian membrane
and its processes in the different sinuses, and also in
the ethmoidal cells.
            8. The TEMPORAL ARTERY

Is considered as the continuation of  the external ca-
rotid, because it preserves the direction of the main
trunk, although the internal maxillary is larger.
   After parting with  the internal  maxillary it pro-
jects outwards;  and  passing  between  the  Meatus
Auditorius Externus  and the condyle of the  lower
jaw, continues upwards, behind the root of the zygo-
matic process of the temporal bone, to the aponeuro-
sis of the temporal muscle: on the outside of which,
immediately under the  integuments, it divides into
two large branches denominated anterior and poste-
rior.
   Before this division the temporal artery sends off
several branches of  very different sizes.
   One, which is considerable in size, and called the
 Transverse  Facial Branch, advances forwards across
the neck of the condyle of the lower jaw, and giving
small branches to the  masseter, runs parallel to  the
parotid duct,  and below it   This branch is spent
   Vol. it.               °^ 
250   Temporal Artery.—Internal Carotid.

upon the  muscles of the face, and anastomoses with
the other  vessels of that part.
  The temporal gives off small branches to the pa-
rotid gland and to the articulation of the jaw.   From
the last mentioned branch small twigs pass to the ear,
one of which enters the cavity of the tympanum by
the glenoid fissure.
  While this artery is on a line with the zygoma, it
sends off a branch called the middle temporal artery\
which penetrates  the  aponeurosis  of the  temporal
muscle, and ramifies under it upon the muscle in an
anterior direction.
  The two great branches of the temporal artery are
distributed in the following manner.   The Anterior
passes up in a serpentine direction on the anterior
part of the temple, and supplies the front side of the
head, and the upper part of  the forehead.
  The  Posterior extends  upwards and  backwards,
and supplies the scalp on the lateral and middle part
of the cranium, and also the bone.
  Ramifications from each of these branches anasto-
mose on the upper part of  the cranium with those of
its fellow of the opposite side.  The anterior branch
also anastomoses on the forehead with the  facial and
ophthalmic artery; and the posterior branch with the
occipital artery on the back part of the head.

    THE  INTERNAL CAROTID ARTERY

Is sometimes called the Artery of the Brain, as it is
almost entirely appropriated to that viscus.
  From its origin to the commencement of its rami-
cations the course of this blood vessel is peeuliarly
tortuous.  In consequence  of which the force of the
blood in it is greatly diminished before it arrives  at
the brain.
  An instance of this curvature occurs immediately 
       Curvatures of the Internal Carotid.    251

after its separation from the external carotid, when it
protrudes outwards so much as to be exterior to that
vessel; after this it ascends to the carotid canal, and
in its course is in contact, or  very near the par va-
gum and  intercostal nerves.
  The carotid canal  in  the  os petrosum is by no
means  straight; it forms a semicircular curve, for-
wards and inwards; and its upper  portion, which is
nearly horizontal,  opens  obliquely against the  body
of the sphenoidal  bone,  at a small  distance from it.
Therefore, after the  artery has  passed through the
canal,  it  must  turn  upwards to get  fairly into the
cavity of the cranium; and of course, its direction
while in the canal, forms almost a right  angle with
its  direction before it enters, and after  it emerges
from it.
   In consequence of this curvature, much of the mo-
mentum of the blood must  be  impressed upon the
cranium.
   After the artery has arrived at the end of the caro-
tid canal, and has turned upwards to get  within the
cavity of the cranium, it bends forwards, and passes
nearly in a horizontal direction, through  the caver-
nous sinus on the side of the sella turcica, to the an-
terior clinoid process; here it again forms a conside-
rable curve, which is directly upwards, and then it
perforates the dura mater.
   These curvatures must also deprive the blood  of
the carotid of a portion of the  momentum which it
has retained after leaving the  bone.
   The object of these various flexures of the internal
carotid appears to be analogous to that of the Rete
Mirabile in certain quadrupeds, which is formed by
the division of this artery into many small branches,
that reunite again, without producing any other ef-
fect than the diminution of  the momentum of the
blood. 
5252
Ophthalmic Artery.
  During its course from the place of bifurcation to
its entrance into the carotid canal, the internal carotid
artery very rarely sends off  any branches.  In the
eanaf it gives off a small twig which enters the cavity
of the tympanum ;  and sometimes a  second which
unites  with the  Pterygoid  branch of the internal
maxillary.
  As it goes by the  sella turcica, it passes through
the cavernous  sinuses,  and gives off  two branches
which are called the Posterior and Anterior Arteries
of the Cavernous Sinus or Beceptacle.
  The posterior  branch goes to that part of the dura
mater  which is connected with the posterior clinoid
process,  and the cuneiform  process of the occipital
bone.  It likewise gives  branches to  several of the
nerves which are contiguous, and to the pituitary
gland.
  The anterior artery also gives branches to the con-
tiguous nerves, to the dura mater, and the pituitary
gland.
  When the internal carotid turns upwards at the
anterior clinoid process, it sends off the

               OPHTHALMIC  ARTERY

Which passes under the optic nerve through the fo-
ramen opticum into the orbit of the eye, and is about
a line and a half  in diameter.
  Although this artery enters the orbit under the op-
tic nerve, it soon takes a position on the outside of it,
but afterwards gradually proceeds to the inner side
of the orbit, crossing over this nerve in an oblique di-
rection, and finally passes out of the orbit near the in-
ternal angle.  In this spiral course it sends off nu-
merous branches, viz.
  A.  To those parts which are auxiliary to the eye.
  b.  To the ball of  the eye. 
       Branches of the Ophthalmic Artery.    253

  c. To the cavity of the nose,  through small fora-
mina in the ethmoid bone, and
  d. To the forehead and external side of the nose.
  These branches generally go off in the following
order.
  1. The Lachrymal artery arises soon after  the
ophthalmic  arrives within  the  orbit,  and  passes
above the abductor muscle to the  lachrymal  gland,
where  it terminates, sending off many small branches
in its course.
  2. The  Central artery of the retina  also leaves
the ophthalmic soon after its  arrival in the orbit: it
is a small vessel which penetrates into  the centre of
the optic nerve, and   passing with  it into the eye is
spread upon the internal surface of the retina.  Here
it appears to terminate in the adult; but in the foetus
it is continued  through the vitreous humour  to  the
capsule of the crystalline lens.
  3. While  the ophthalmic is passing over the optic
nerve the branches which enter the ball of the  eye
leave it.  Their number varies, but they form three
classes, viz.  The Long Ciliary, the Short Ciliary,
and the Anterior  Ciliary arteries.  (See description
of the eye,  vol. i. p. 352,) the  supra orbitary  and
muscular branches leave it also near the same  places.
  4. The Supra Orbitary Branch often gives off
several muscular twigs : but it passes out of the orbit
through  the supra  orbitar foramen, and generally
divides into two  branches,  one  of which is spent
upon the periosteum, and  the other upon the skin
and muscles of the forehead.
  5. There  are sometimes two muscular branches, a
Superior and an Inferior.   The superior branch  is
often deficient: when it exists it supplies the  levator
palpebra, the levator oculi, obliquus superior, &c. ;
but these  parts are often supplied by the branches
aliove  mentioned..  The supra OFbitar  so frequently 
254    Branches of the Ophthalmic Artery.

gives off branches  to  the muscles that  it has beeu
called the Superior Muscular Branch.  The inferior
muscular  branch is more constant.   It commonly
supplies the rectus  inferior, the adductor, and  the
inferior oblique muscles,  and also the lachrymal sac,
and the lower eyelid,  &c.
  When the artery is on the inside of  the nerve it
sends off the two branches to the cavity  of the nose,
viz,  The Ethmoidal Arteries ; and also, branches to
the eyelids.
  6. The Posterior Ethmoidal branch  is first.   It
passes  between  the levator and abductor muscles,
and above the obliquus superior; and penetrates the
cavity of the cranium  by  the posterior orbitary fora-
men : after giving some twigs  to the dura mater, it
passes  to the posterior cells of  the  ethmoid by the
foramina of the cribriform  plate of  that bone,  and
sends a small branch to the  Schneiderian membrane
on the back part of the septum of the nose.
  7. The Anterior Ethmoidal artery arises from the
ophthalmic nearly opposite  to the anterior orbitary
foramen, through which it passes: and  after enter-
ing the cranium is distributed  like the other through
some of a foramina of the  cribriform  plate  to  the
anterior cells of the ethmoid bone, and  to the ante-
rior part of the Schneiderian membrane on the sep-
tum of the nose,  to  which  it  sends a considerable
branch.
  In its course it sends twigs to  the  frontal  sinuses,
and  to the dura mater and its  falciform process.
  8. The arteries of  the Palpebrx are called Supe-
rior and Inferior;  they  leave the ophthalmic  near
the  loop  or pully  of the superior oblique  muscle.
The inferior comes off first; it sends branches to the
ligaments of the tarsus,  the  caruncula lachrymalis,
and the parts connected with the cartilage of the un-
der evejid, and unites with the lachrymal artery near 
Branches of the Ophthalmic Artery.—Carotid. 255

the external canthus, forming an arch called the In-
ferior Tarsal Arch.
   9.  The Superior Artery supplies the superior part
of the orbicularis muscles, the ligament  and carun-
cula also : and  it likewise unites with a  twig of the
lachrymal, and forms the superior tarsal  arch.
   Soon after sending off the palpebral branches, the
Ophthalmic Artery arrives at the  internal  canthus,
and then finally divides into two branches, the nasal
and the frontal.
   10. The Nasal Branch passes above the superior
part of the  lachrymal sac and the ligament of the
eye-lid to the nose ; after sending a twig to the fron-
tal muscle and  the lachrymal sac, it passes down the
side of the nose and  anastomoses with the facial ar-
tery.
   11. The Frontal Artery is not so large as the na-
sal ; it generally divides into three parts. A super-
ciliary branch which  is  principally spent upon the
eyebrows; a superficial branch which is spent  upon
the forehead;  and a branch which is distributed to
the pericranium.
   The internal carotid, soon after parting with
the ophthalmic, sends off,  in a posterior direction, a
branch to join  one  from  the vetebral artery.  From
its distillation  this vessel is called the arteria com-
municans.
   After this it sends off another branch, which is so
large  that it may be considered as a continuation of
the main trunk :  this is called the middle artery of
the brain, or the Arteria Sylviana.  It runs outwards
nearly in the direction offthe  fossa  Sylvii^ which se-
parates the anterior from trtfe  middle lobes of the ce-
rebrum.  In its course it divides and subdivides into
numerous branches which are spread  upon the Pia
Mater, and finally enter the surface of the brain in a
very  minute state. 
 256   Right and Left Subclavian Arteries.

   The internal carotid  then terminates in a branch
 which is smaller than the last mentioned,  and from
 its  situation  is called  the Anterior Artery of the
 Brain, or Arteria Callosa.  This vessel first inclines
 towards its fellow on the opposite side, and after ap-
 proaching within  half an  inch of it, forms another
 curve, and runs forward to the anterior part of the
 brain, dividing itself gradually into branches which
 pass in several directions.
   When these anterior arteries  are nearest to each
 other, a  small transverse branch,  which  passes at
 right angles,  connects them  together.   This branch
 completes the anterior part of the Circle of Willis.
   It crosses immediately before the sella turcica and
 pituitary gland,  and sends off branches whieh pass
 to the third ventricle, to the fornix and septum luci-
 dum, and also to  the pia mater.
   The Anterior Arteries of the  brain  also  send off
 branches  to the  optic and olfactory nerves; to the
 opposite  surfaces of the two hemispheres on each
 side of the falx ; to their inferior surfaces, and to the
 corpus callosum.
   They have likewise some  branches which anasto-
 mose with those of the middle artery of the brain,
 and  of the vertebral artery.

           The SUBCLAVIAN Arteries.

   The right subclavian may be considered as the
 continuation  of the arteria  innominata.   This last
 mentioned artery, after  leaving the aorta, forms a
 curve or  arch, which extends obliquely backwards
 and  outwards, over the first rib to the axilla, crossing
 the trachea "in its course.  At the distance of an inch
 and a quarter, or an inch and a half  from its origin,
it sends of the right carotid,  and then, assuming the
 name of Right Subclavian,  continues  in the above
stated direction. 
         •  The Left Subclavian Artery.       257

  The chord of the curve of this  artery, and  the
chord of the curve of the aorta, are not in the same
direction, but form an angle with each other.
  The position of the left subclavian is somewhat
different from that of the right.  Its origin is posterior,
and, therefore, the direction of the chord of its curve
is more immediately lateral.  The curve or arch is
also smaller.   The situation of the two  subclavians
as relative  to the contiguous  parts,  is,  therefore,
somewhat different; but each of them proceeds be-
tween the anterior and the  middle scaleni muscles,
and when they have  arrived at these  muscles, their
respective positions are very similar.
  The anterior and middle scaleni muscles arise from
the transverse processes of several of the cervical
vertebrae, and are inserted into the first rib, one be-
fore the other, so as to leave a considerable space be-
tween them.  The subclavian arteries pass through
this space, and before they arrive at it, but when they
are very near the above mentioned  muscles, they
send off several  very important  branches in various
directions,  viz. to the cavity of the cranium, to the
parietes of  the thorax, to the thyroid  gland, and to
the lower part of  the neck.
  They proceed near to  the  scaleni  muscles before
they send off any branches; and it is to be observed,
that the subclavian veins which correspond with these
arteries,  are anterior to them, for  they pass before
the scaleni muscles, and not between them.
         The internal mammary Artery

Goes downwards,  from  the lower and anterior part
of the subclavian, along the inner side of the anterior
scalenus muscle.  It proceeds, exterior to the pleura,
across the cartilages of the true ribs, and and near their
middle ; and, continuing between the  cartilages and
the diaphragm,  exterior  to the peritoneum, terwi-
   Vor. II-               W 
258  Course and Distribution of the Inferior

nates on  the rectus  abdominis muscle,  in branches
which anastomose with those of the epigastric artery*
In this course  it gives branches to almost all the
parts to which  it is  contiguous, viz. to the muscles
and glands at  the lower part of  the neck; to the
thymus gland ;  to the parts in the intercostal spaces;
to the sternum;  to  the  mediastinum and  pericar-
dium ; to the diaphragm and  to the muscles of the
abdomen.
  From some of its ramifications upon the parts be-
tween the ribs,  small branches  go off to the mamma,
and thereby give a name to the artery. There is also
a small vessel which  is sent off by the mammary ar-
tery, or by one of its upper branches, which accom-
panies the phrenic nerve to the diaphragm.
          The inferior thyroid Artery
Arises from the upper side of the subclavian nearly
opposite to the origin of the internal mammary.   It
passes upwards  and inwards,  between  the carotid
artery and the spine, to the thyroid gland : then it
anastomoses with the branches of the superior thyroid
on the same side, and with  those of its fellow on the
opposite side.
  This vessel sometimes sends off large branches  to
the muscles at the lower part of the neck.

             The vertebral Artery

Arises from the upper and  posterior part of the sub-
clavian.   It goes upwards  and backwards between
the muscles which lie on the front of the spine, and
passing under the transverse process of the sixth or
seventh cervical vertebra, enters into the canal form-
ed in the transverse processes of  the vertebrae.   In
this course, as it proceeds from the third to the se-
cond cervical vertebra, it inclines outwards laterally,
and, in  its passage from the transvere process of 
       Thyroid and the Vertebral Arteries.    259

the second  to  that of the  first vertebra, it forms a
considerable  curve,  the convexity of which has a
lateral and external aspect.  After passing the trans-
verse process of the  Atlas, it is  turned  suddenly
backwards,  in a groove, and  finally passes  through
the great occipital foramen into the  cavity of the cra-
nium.  It then proceeds upon the cuneiform process,
of the occipital bone,  under the Medulla Oblongata,
and joins its fellow so as to form an acute angle with
it near the union of the  medulla oblongata with the
pons Varolii.  From each of the vertebral  arteries,
before their  union, there generally goes off a small
branch called the  Posterior Meningeal, which is
spent upon the posterior part of  the dura mater.
  The trunk formed by the  union of the vertebral
arteries is called
             The BASILAR Artery.
It extends forward near to the anterior part  of the
pons  Varolii, where  it bifurcates;  but previously
sends off several branches on each side.  The first
pair go off in a  lateral direction, soon after its com-
mencement, near the  back part of  the pons Varolii,
and are spent upon the medulla oblongata,  the  pons
Varolii, and the  other contiguous parts,  and also
upon the fourth ventricle and the Plexus Choroides
of that cavity.   They are  called  the  Posterior or
Inferior Arteries of the Cerebellum.
  Two other lateral branches, which are called the
Superior Arteries of the Cerebellum, go off from the
Basilar artery,  near its anterior  extremity.   These
are principally spent  upon the crura of  the cerebel-
lum and cerebrum; upon the cerebellum itself, and
the contiguous parts.
   Soon after sending off the last mentioned arteries,
the Basilar artery divides into two branches, which
^Jso take a lateral direction, and are of  considerable 
360  Arteri ±s of the lower part of the Neck.

size.   In their course outward,  these  branches are
curved with their convexity forward.   About ten  or
twelve lines from its commencement,  each of  them
sends off a branch called the Arteria Communicans,
which  passes  directly  forward, and  communicates
with the internal carotid, thus forming the arrange-
ment which is called the Circle of  Willis.*  After
sending off these arteries, they continue their lateral
direction, and are distributed principally to the pos-
terior parts of  the  cerebrum.  These terminating
branches of the Basilar Artery, are called the Pos-
terior Arteries of the Cerebrum.
        The superior intercostal Artery
Arises from the upper part of the Subclavian, after
the Vertebral  and Thyroid  arteries, and very near
them.   It  descends by the side of the spine across
the first and second ribs, near their heads,  and exte-
rior to the great intercostal nerve.  It generally forms
two branches,  which  are appropriated to the mus-
cles, &p. in the first and second intercostal spaces,
and sometimes a small branch is continued to  the
third intercostal space. From each of these branches
a small vessel proceeds backwards, and is spent upon
the contiguous muscles, &c. on the back of  the tho-
rax.   The Intercostal Artery also sends a branch
Upwards to the deep-seated parts of the neck.
   In addition to the arteries above  mentioned, there
are several others of considerable  size which  origi-
nate either directly or indirectly from the subcla-

  * The arteria communicans is also considered as a branch of the Inter-
nal Carotid.  The arrangement here alluded to  is very remarkable. As
the branches which pass off laterally from the single trunk of the Basilar
Artery unite to the Internal Carotids, and the Internal Carotids are united
to each other, there is an uninterrupted continuation of artery, which en-
closes a portion of space of a determined form ; but  this form resembles
an oblong square more than a circle.  By this connexion blood will pass
from any one of the four arteries of the brain to all the o'Vt1?, 
       Branches that go off in the Axilla.     261

vian, and are spent upon the lower portion of the
neck, and the contiguous parts.  These arteries are
very different in different  subjects, especially  as to
their origin.   Two of them, which have been called
the Anterior and Posterior Cervicals, are generally
distributed  to the muscles and  other parts which lie
on the lower portion of the neck anteriorly and pos-
teriorly.
  A third, which passes transversely on the lower
part of the neck, is called the Superior  Scapular.
  In some cases the two Cemical Arteries arise from
the  subclavian, after the mammary and the thyroid,
in a common trunk, which soon divides.   Very fre-
quently  they go off from the Inferior  Thyroid.—
Sometimes  one of them goes  oft' from the Inferior
Thyroid, and the other from one of the branches of
tho  Subclavian.*
   The Superior Scapular most commonly arises with
some other artery,  and very often from the Inferior
Thyroid.   It runs  transversely outwards, within and
above the clavicle,  and passing through the notch in
the  upper costa of the scapula, divides into branches
which are distributed to the parts on the dorsum of
that bone.
   The subclavian artery,  in its progress from the
aorta to the axilla,  forms an arch or curve, over the
first rib, as has been  already observed.  The  ante-
rior scalenus muscle is before it, and the  great nerves
of the upper extremity are above it.  After passing

  * Haller paid great attention to the arterial system, and made many dis-
sections, with a view to engravings of it, which he published with descrip-
tions, in folio fasciculi.
  These fasciculi have been collected, and, with some other engravings,
form a large volume, entitled icones anatomic je, which is truly valuable.
  There are some very interesting observations on this work of Haller's,
and also on these arteries, in a description of the arteries, by Dr. Bar-
clay of Edinburgh, which I have read with advantage, as well as a work
on the muscles by the same author. 
262    Brancl^es tliat go off in the Axilla.
between the scaleni it  descends  upon the first and
second rib into the axilla.   The nerves which were
above, descend with it: at first they are  necessarily
ex'terior to  it, but  they form a  plexus  which  the
artery enters into, so as to be  partly surrounded  by
them.   This course of the artery is obliquely under
the clavicle, and behind the pectoral muscle.  In the
axilla, the vessel  and nerves which  surround it are
placed between the tendons of the pectoralis and the
latissimus dorsi muscles.   Here the artery  takes the
name of axillary, and sends off several important
branches.
  The principal branches that go off from  the axil-
lary artery are distributed,
  1st. Anteriorly, to the pectoral muscle, and the
parts on the anterior surface of the thorax.
  2d.  Posteriorly, to the muscles which  are  on the
scapula and contiguous to it; and
  3d.  To the parts which are near the upper extre-
mity of the os humeri.
               Anterior Branches.

  The arteries which go to the pectoral muscle, &c.
are very various in different subjects, both as to their
number, origin, and size.
  They have also been called by different names, as
Thoracicx, Mammarix Externx, fyc.
  There are almost always three of  them, and very
often more;  one of  them, which is called by  several
authors the Acromialis, proceeds towards the end of
the clavicle, and generally passes  out at the interval
between the deltoid and the pectoral muscle, sending
various branches to the contiguous parts; the  largest
of its branches often passing in the  direction of the
interstice between those muscles.
  Another of these arteries> which is called  Superior 
        Branches that go off in the Axilla.    263

Thoracic, is generally very small: it often is a branch
of the above mentioned Acromialis.
  There is very often  to  be found  here an artery
called the Inferior Thoracic, or the External Mam-
mary, which is of considerable length, although  its
diameter is not very great.  This artery originates
near the two last mentioned, and sometimes from the
Acromialis.  It often  extends  downwards as low as
the sixth rib, and send branches to the anterior part
of the thorax, to the mamma, and the other contigu-
ous parts.   Many of the small  branches of this ar-
tery anastomose very freely with  those of the inter-
nal  mammary.
  There are always small arterial branches in the
axilla, which  ramify upon the glands  and adipose
matter always existing there.  They often arise  by
one  commom trunk, which is  called the Axillary
Thoracie.

                Posterior Branch.
  One large artery is commonly sent  to the muscles
on  the  scapula,  which  is called  the  Scapular, the
Common Scapular,  or the Internal Scapular.  It
commonly passes off  from the axillary after  the tho-
racic arteries, and supplies the  muscles  on both sur-
faces of the scapula.   This large vessel passes down-
wards a short distance in the direction of the inferior
costa of the  scapula, and  soon sends off a branch
that winds round to the dorsum of  the bone, to  be
distributed to the infra spinatus and  the contiguous
muscles, which is called the Dorsalis  Scapulx.  The
main trunk then inclines to the  subscapularis muscle,
and generally divides  into two branches, which are
distributed to the subscapularis, teres major, latissi
mus dorsi, &c.
   Sometimes the Scapular artery divides into two
branches before it sends off the dorsal.  In this case 
 2t>4             Humeral Artery.

 the last mentioned artery goes off from one of those
 branches.
          Branches near the Os Humeri.

   The arteries which are  near the body of the os
 humeri at its upper end, are generally two in number,
 and denominated the Anterior and Posterior Circum-
flex.    Sometimes they arise separately, and some-
 times in a common trunk from the axillary artery.
 Frequently one of them arises from the scapular.
   The  Anterior  Circumflex passes between  the
 united heads of the biceps and coraco-brachialis mus-
 cles and the body of the os humeri, at a small distance
 below  its head.  It sends branches to the capsular li-
 gament, the periosteum of the os humeri, the mem-
 branes of the groove for the long head of the biceps,
 the upper portions of the biceps and couaco-brachia-
lis, and some contiguous muscles.
   The Posterior Circumflex proceeds between the
subscapularis and teres major muscles, and continues
 between the os humeri and  the head of the triceps
and the  deltoides.  It is distributed to  the  muscles
and parts about the joint, especially the deltoides.
   These arteries surround the os  humeri," and the
small  branches anastomose  with each other.   The
Posterior Circumflex is much larger than the Ante-
rior.
   The  great artery of the arm proceeds from  the
axilla to the elbow; and, during this course, is gene-
rally denominated
            The  HUMERAL Artery.*

Its direction is influenced by the position of the os
humeri.   When the'arm hangs down, with the palm
of the  hand  presenting forward, this  direction is
* It is called Brachial Artery by several w.-ite-? 
        Branches of the Humeral Artery.     265

somewhat spiral.  The situation of the artery is on
the inside of the biceps muscles,  and between that
muscle, and the triceps extensor.   It also continues
very near and on the inside of the tendon of the bi-
ceps,  and under the  Aponeurosis which proceeds
from that tendon.   In consequence of the spiral or
oblique course of the artery, its direction would be
from the inside of the tendon of the biceps to the ra-
dial side of the fore arm, but soon  after it  passes
across  the joint of  the elbow, it divides into two
branches: one  which  preserves, for  some distance,
the direction of the  Main Trunk, is  called the Ra-
dialartery: the other, which inclines obliquely down-
wards and towards the ulna, is the Common  Trunk
of the Ulnar and Interosseal arteries.
  During this course, the humeral artery sends off
several branches to the muscles and other parts on the
os humeri.  The largest of them is denominated the
Profunda Humeri or  Spiralis.   This artery very
often arises as high as the insertion of the latissimus
dorsi, and passing between the heads of the triceps
extensor muscle, proceeds downwards under  that
muscle, in a spiral direction, towards the external,
or radial condyle.   It sends several branches to the
triceps and the contiguous muscles, and one consider-
able branch, which is generally called the Profunda
Minor, to the parts contiguous to  the internal con-
dyle.   The ramification of these branches near the
cendyle frequently anastomose with small branches of
the radial and ulnar arteries.*
  A small branch frequently arises from the Hume-
ral artery,  at a short distance from  the  Profunda
Humeri, which sends a ramification to the medullary

  * The Profunda sometimes originates from the scapular, or one of the
circumflex1.  The profunda minor sometimes has a distinct and separate
origin, lower down than the other.
  Vol. h.              34 
266
Radial Artery.
foramen of the os humeri.   This vessel is, therefore,
denominated Arteria Nutritia.
  There are very often several anastomoses between
the branches of the humeral artery, which originate
above the elbow, and certain branches of the'Radial
and Ulnar arteries, which are  called from their  di-
rection recurrents.  Among these arteries there is
generally one  of  considerable  size, which proceeds
across the elbow joint  near  the internal condyle.—
Sometimes this is the ulnar recurrent, which goes up
to anastomose with the branches of the profunda;
but more frequently it is a separate branch of  the
Humeral artery which goes off a  little above  the
elbow, and passes  across the articulation, near  the
internal condyle, to anastomose  with the branches of
the ulnar artery.   This artery is denominated  the
Anastomotica.
  There  are  often other  branches sent off by  the
humeral artery; but they are  commonly small, and
very irregular.
  The two great ramifications of the humeral  ar-
tery on the fore arm have very different directions.
The Radial artery preserving the course of the main
trunk, while  the Common  Trunk of the Ulnar and
Interosseal projects from it in a direction downwards
and towards  the ulna, passing under the  pronator
teres, &c.
               The radial Artery

Passing over the pronator teres muscle proceeds  be-
tween the supinator radii longus and the flexor carpi
radialis, very near to the lower  end of the radius,
without changing its direction materially, being deep-
seated above and superficial below; it then alters its
course, and, passing under the  tendons of the exten-
sors of the thumb, to the back part of the radius, it 
Course and Ramifications of the Radial Artery. 267

continues between the metacarpal bones of the thumb
and of the index finger, when it divides  into three
branches.
  In this course it gives off but few branches.   The
first is the Radial Recurrent, which passes upwards
and towards  the external condyle, and  frequently
anastomoses with the ramifications of the profunda
humeri.
  The branches which it sends off between the origin
of the recurrent and the lower end of the radius are
generally very small, and distributed to the parts im-
mediately contiguous to the artery.—Before it turns
under the tendons of the extensors of the thumb, it
sends a branch over the wrist towards the root of the
thumb, from which  proceeds a branch to anastomose
with the volar branch of the ulnar; and another, not
so large, which is frequently continued on the radial
or external side of the thumb, very near to its  extre-
mity.  While the radial artery is under the aforesaid
tendons, it  sends off small branches to the back  of
the wrist and  back of the  hand, and  often to the
back of  the thumb.   Those which are distributed to
the wrist and back of the hand, generally anastomose
with the small branches of the ulnar and  interosseal
arteries.
  The three  branches into which the  radial artery
divides between the metacarpal bones of  the thumb
and index are, 1st, a branch to the external side of
the index ; 2dly, a branch to the thumb, that some-
times divides into two which pass up on the anterior
or volar surface, and sometimes continues,  without
much diminution, on the internal side of the thumb,
near to  the end of the last phalanx; and, 3dly, a
branch, called Palmaris Profunda, which dips down
into the palm of the hand, and, proceeding in con-
tact  with the  metacarpal bones, under  the  flexor
tendons, &c. forms an arch which extends across the 
268 Origin of the Ulnar and Interosseal Arteries.

hand, and  often terminates by anastomoses with  an-
other arch, soon to be described, which is formed by
the ulnar artery.
   This flexure, which is denominated Arcus Pro-
fundus,  sends off branches of a very small size, which
are distributed to the bones, ligaments, muscles,  &c.
contiguous to it.
  The common trunk of the ulnar and interos-
                  seal  Arteries

Passes under several of the  muscles which originate
from the internal condyle, and  between the flexor
sublimis  and the flexor profundus.  Before  the Ulnar
Recurrent goes off from  this vessel, the interosseal
artery often leaves it.  This recurrent artery passes
upwards between the muscles of the internal condyle,
and  distributes branches among them.  It then passes
up in the groove  behind the internal  condyle,  and
anastomoses with the branches of the Anastomotica
or Profunda Humeri.
   The ulnar and interosseal  arteries  separate from
each other at the distance of fifteen or twenty lines
from the origin of the radial artery, very near  the
commencement of the interosseal ligament.

             The interosseal Artery

In a majority of cases, arises in a single branch from
the common trunk of the ulnar and interosseal.  When
it does so,  the single branch  soon sends off the Pos-
terior  Interosseal artery, which perforates the inte-
rosseous  ligament, and passes down on its posterior
surface, while the main branch continues on the an-
terior  surface of  the  ligament, and is denominated
the Anterior Interosseal  Artery.   In some cases the
main branch  proceeds on the anterior surface as  low
as the upper edge of the pronator quadratus muscle,
before it sends off the posterior branch.  Sometimes 
Course of the Ulnar Artery.       269
the anterior and posterior interosseals arise separate-
ly.   In this case the posterior soon perforates the li-
gament.
  The Anterior Interosseal passes  down almost in
contact with the ligament, and gives  branches to the
contiguous parts in its course.  It generally perforates
the interosseous ligament near the wrist, and sends
off many small branches to the back of the wrist and
hand, which anastomose with the small branches of
the radial and the posterior interosseal arteries.
  The Posterior Interosseal soon  gives off a recur-
rent or anastomosing branch, and then proceeds down-
wards  towards  the wrist,  sending  branches in its
course to the extensor museles and tendons.
  This vessel sometimes divides into two branches.

                The ulnar Artery.

  The Ulnar artery proceeds among the muscles ob=
liquely downwards, and is not superficial until it has
arrived within three or four inches of the carpus: it
then continues towards  the hand, sending off very
small branches  in its progress.   It  passes over the
annular ligament at the wrist, and winds round the
pisiform bone:  here it is supported by a delicate liga-
ment,  which seems to lie upon it:  from this it passes
upon  the palm  of the  hand, under  the aponeurosis
palmaris, and over the tendons of the flexors of the
fingers.   When thus situated, it forms, in perhaps a
majority of subjects, an arch or bow, called Arcus
Sublimis, which extends across the palm of the hand,
from  the ulnar  towards  the  radial  edge, and, after
sending branches to the fingers, &c. from its convex
side, terminates near the root of the  thumb, by anas-
tomosis with that important branch of the radial ar-
tery, which  passes up  on the inside of the  thumb. 
270            Digital Arteries.
The Arcus  Sublimis almost always sends off small
branches to  the integuments, &c. on the palm of the
hand.   It often sends off, near the root of the meta-
carpal bone  of the little finger, a branch which passes
between the flexor tendons and the metacarpal bones,
and anastomoses with the Arcus Profundus. It then
generally sends off a branch to the inner or  ulnar
side of  the little finger;  and  afterwards  three
branches in  succession, which pass  from  its convex
side towards the angles formed by the fingers.  These
are called
              The Digital Arteries.

When they  have  arrived near  to  the heads of the
first phalanges of the fingers, each of these arteries
divides into two branches, one of which passes along
the side of one of  the fingers to its extremity, and the
other on the opposite side of the next finger : and in
this way they pass on the sides of all the fingers, ex-
cept the inside of the little finger and the outside of
the index.
  These branches of the digital arteries are called
Digito Radial and Digito Ulnar arteries, according
to the  sides  of the fingers on which they  are placed.
They are situated on the angle, if it may be so term-
ed, which is formed by  the  anterior and  lateral sur-
faces of each finger.  In their course from the  basis
to the extremity of the finger, they send off  very
small  transverse branches,   which  anastomose  with
each other, especially near the other.   Some trans-
verse branches  are observable  on  the posterior as
well as the anterior surfaces.  Near the  extremity
of each finger, beyond the  insertion of the flexor
tendon, the  extremities of these  arteries  ramify mi-
nutely.  Some of  these small branches go to the
skin,  and others anastomose with  their fellows  of 
Bronchial Artery.
271
the opposite side.   Some also go to the back of the
fingers.*

                      section iil

Of the Branches which go off between the arch and
       the great bifurcation of the AORTA.

                       PART I.

            In the Cavity of the Thorax.

   THE arorta sends branches to the Lungs, to the
oesophagus, and  to the parietes of  the thorax.

               The bronchial Arteries

Are the vessels which go from the aorta to the  ram-
ifications of the  trachea, and the  substance of the
lungs.   They are not  large, and are v.ery irregular
as to number  and origin.
   In a majority  of cases the right lung is supplied, in
part, by a  branch from the  first aortic intercostal of
that side ;  while the left lung receives two or three
branches  from the aorta directly.   In some  cases a
large vessel arises from the  aorta, which divides into
two branches, one of which goes to  each lung.

  * The distribution of the radial  and ulnar arteries in the hand, is very
different in different subjects.
  Upon examining a large number of injected preparations in Philadelphia,
it was found that, in a very small majority of them, the ulnar artery form-
ed an arcus sublimis, whose branches  extended as far as the ulnar side of
the index, and sometimes beyond it.
  That, in near a third of the preparations, the ulnar artery ramified with-
out forming an arcus,  and supplied only two of the digital branches, viz.
the first two on the ulnar side.  In such cases  the radial artery generally
made up the deficiency of the ulnar, but in a few  instances the interosseal
was extended on the palm of the hand, and supplied the radial side of the
middle finger and the corresponding side of the index.
  In a few instances also the ulnar artery was still more deficient, and the
radial was proportionally extended. 
 272    (Esophageal and Intercostal Arteries.

   The Bronchial arteries  frequently  send small
 branches to the posterior mediastinum,  the pericar-
 dium, &c.
   Injections have  shown, that there is a direct com-
 munication  between these vessels and the  branches
 of the pulmonary  artery.

             The  (Esophageal Arteries

 Are very small vessels, which generally arise from
 the aorta,  but sometimes are branches  of the bron-
 chials or intercostals that are spent upon the cesopha-
 gus.   They occur in succession,  and sometimes are
 five or six in number.   They also send twigs to the
 contiguous parts, and the lowermost often descend to
 the stomaeh.

             The  Inferior Intercostals

 Are the arteries which  proceed directly  from  the
 aorta to the parietes of the thorax.   Their name is
 derived from their position between the ribs.  They
 are ramified on the intercostal muscles and  ribs, and
 on the pleura and some of the contiguous parts.  They
 are called Inferior or  Aorta Intercostals,  to distin-
 guish them from the superior intercostals, which are
 derived from the subclavian artery.   Their number
 varies from ten to  eight, according as  the superior
 intercostals are more or less numerous.
  They originate in pairs on the posterior surface of
 the aorta.   The uppermost of them pass  obliquely
 upwards, and the  lowermost  nearly in a horizontal
 direction, to the lower edges of those ribs  to which
 they are appropriated.   They meet the rib near its
tubercle, or place of junction with the transverse
 process of the vertebra, and  then proceed forward,
 between the internal and  external  intercostal mus-
 cles, in a superficial but  large groove, which is ge- 
               Intercostal Arteries.            273

nerally to be found  on the interior margin of the
lower  surface  of  the rib.*  There is necessarily a
difference in the length of the right and  left inter-
costals, owing to the position of the aorta, which is
rather on the left of the  spine.   In  consequence of
this circumstance, the cesophagus is anterior to, and
also in contact with those of the right side.
   They generally send  off an important branch, call-
ed the Dorsal, which arises near  their origin,  and,
passing backwards,  sends ramifications to the  mus-
cles of the back.  From this dorsal branch also pro-
ceeds a ramification,  which enters the spinal cavity,
and is spent upon  its membrane and upon the medulla
spinalis.
   After the Intercostals,  in their progress forward,
have passed beyond  the middle of the ribs, they send
off a branch, whieh  generally proceeds very near to
the upper side of  the lower rib.   The main trunk
generally leaves the  lower edge of the rib when it
has arrived within one-third of the length of the bone
from its anterior extremity.   It then generally di-
vides into several branches, some of which are spent
upon the pleura, and others on the intercostal and
the contiguous muscles.
   According to the  situation of the different inter-
costals, some of their ramifications  communicate  with
those of the internal and external mammaries, of the
phrenic, the lumbar, or the epigastric arteries.

                  * See Vol. I. page 95.
Vol. ii.
35 
274          Cavity of the Abdomen.
                   PART II.

         In the Cavity of the Abdomen.

  The aorta passes into the cavity of the abdomen
between the crura of the diaphragm, as has been al-
ready mentioned. In its course from the crura to its
great bifurcation, it sends off one pair of small arte-
ries, called Phrenic, to the diaphragm.  Three sin-
gle  arteries, the cceliac, the superior, and the in-
ferior mesenteric,  to  the viscera of  the abdomen.
A pair of large arteries, the emulgents, to the kid-
neys, with  several that are very small to  their ap-
pendages ;  as the Spermatices,  Capsular,  the  Ure-
teric, and the Adipose.   In addition to these, there
is one pair  of small arteries that go to the  testicles,
or to the ovaria and the uterus, and four or five pair,
called  Lumbar  Arteries, that go off  laterally,  like
the intercostals, to the parietes of the abdomen, and
to the muscles, &c. on the back, which  are contiguous
to them.

              The phrenic Arteries

  Are ramified  on  the concave surface of the dia-
phragm,  and are almost always two in  number ;  they
are denominated right and left from  their position.
They commonly originate separately from the aorta,
but sometimes they arise in a common trunk which
soon divides.  In some instances  they are derived
from the cceliac.  In a few cases, the aorta  furnishes
one, and the cceliac the other.  Each  of the phrenic
arteries commonly crosses the crus  of the diaphragm
on  its respective side, and proceeding laterally,  in a
circular direction, often ramifies so as to form an in- 
        Distribution of the Coeliac Artery.    275

ternal and external branch.  Each of them generally
sends branches to the  cardia or  cesophagus, to the
glandulae renales, and other contiguous parts.
              The CCELIAC Artery

Is the first great branch given off by the aorta in the
abdomen, and is distributed almost entirely to the sto-
mach, the liver, and the spleen.  It projects from the
anterior part of the  aorta so as to form a right angle
with it, and is of course nearly horizontal, when the
body is erect.
  The main trunk of this great artery is so remarka-
bly short, that it has  been compared to the stump of a
tree: for at the distance of half an inch from its origin,
it generally divides  into three  branches, which pass
to the stomach, the  liver, and the spleen,  and are,
therefore, denominated the Gastric or Coronary, the
hepatic and the splenic arteries.
  The  first mentioned branch may be called
  the superior coronary or gastric artery,

To distinguish it from other branches, soon to be de-
scribed.  It is commonly in the  centre of the three
great ramifications  of the  cceliac, and is  also the
smallest of them.   It proceeds from its origin to the
upper orifice of the stomach or cardia, and continues
thence along the lesser curvature of that viscus, until
it approaches near to the pylorus.  In  this course it
sends branches to the cesophagus, which frequently
inosculate with the oesophageal arteries.  It also fur-
nishes branches to the cardia, which partially surround
it; and on this account,  the artery has been called
 Coronary.  Some of  these last  mentioned branches
 are often continued on the great extremity of the sto-
 mach, and anastomose with those ramifications of the
 splenic artery, called  Vasa Brevia.
    It continues  on  the lesser curvature between the 
276
Distribution of
lamina of the small omentum,  and sends off succes-
sively branches which  pass between the peritoneal
and muscular coats, and are distributed to the ante-
rior and posterior surfaces of the stomach, communi-
cating with the branches of the inferior gastric arte-
ries,  soon to be described.*

              the hepatic artery

Proceeds from the great ramification of the cceliac to
the transverse fissure of the liver called the Portx, in
which it generally divides into two branches.  In this
course it very frequently sends off an  artery to the
pylorus, which ramifies about  the small extremity of
the stomach, and often inosculates with some of the
branches of the superior coronary.  This branch is
called the Pylorica, and sometimes it arises from the
artery next to be mentioned.

        The GASTRICA INFERIOR dextra,

Which also generally originates from the main trunk
of the hepatic, but sometimes from one of its branches.
It is an artery of considerable size, which proceeds
along the great curvature of the stomach, from the
pylorus towards the  great  extremity, between the
lamina of the anterior  portion of  the  omentum, and
distributes  its  ramifications to both sides of the sto-
mach, and also  to  the Omentum.  In  its  progress
from the hepatic artery to the stomach, it sends off
branches  to the Duodenum, and to the right end of
the Pancreas.
   The two great branches into which the hepatic
artery divides, are denominated right and left, from
the lobes of the viscus, to which they are respective-
ly appropriated.  The right branch is the largest.—

  * This artery sometimes sends a branch to the liver. When this is the
 case,, it is always very lar^e. 
the Splenic Artery.            277
Before it penetrates the substance of the liver, it
sends off a branch to the gall  bladder, called the
Cystic Artery.
  The branches of the  hepatic artery ramify very
minutely in the liver, as has been  stated in the ac-
count of that organ.
  The last great branch of the cceliac is

              The SPLENIC Artery,

Which is generally supposed to  be larger  than the
hepatic in adults, although it is less in children.  It
proceeds in a transverse direction from its  origin to
the spleen: its course is not straight, but meandering
or serpentine.  It is situated behind and above the
pancreas, and passes along the groove in the  upper
edge of  that viscus.  In  its progress, it  sends off
many small branches, and one that is of considerable
size, to the Pancreas.  It also sends  one branch to
the left extremity  of the stomach, which arises com-
monly from the main trunk, but sometimes from the
ramifications, which are soon to be mentioned.   This
branch, which is called

        The GASTRICA INFERIOR SINISTRA,

Is sometimes, but not often very large: Its course is
from left to right.-   It is situated between  the  lami-
na of the anterior portion of the  omentum.   It sends
some small  branches to  the  omentum, and  others
which are larger and more numerous, to both sides
of the stomach.   Some of these  last mentioned anas-
tomose with the ramifications of the gastrica dextra,
which come from the hepatic.
   When the splenic artery approaches near to the
spleen, it divides into  four,  five, or six  branches
each of which penetrates into that viscus  by a dis- 
278 Distribution of the Superior Mesenteric

tinct foramen, and then ramifies in  the manner  de-
scribed in the account of the structure of the spleen.*.
   Either from the splenic artery, or from these rami-
fications, four or five branches pass to the large extre-
mity of the stomach, and ramify there, communicating
with the vessels already described.   These  arteries
have received great  attention from physiologists, and
are denominated Vasa Brevia.

        The  SURERIOR MESENTERIC,
Which is the second great  branch given off in  the
abdomen by the aorta, is not very different  in size,
from the cceliac, and originates about  half  an inch
below it.   It is distributed  to  the small  intestines;
to that portion of the great intestine, which is situated
on the right  side of the abdomen; and to the arch of
the colon.   From its origin it proceeds downwards,
under the pancreas, and over the lower portion of the
duodenum, to the commencement of the mesentery.
When  it has arrived  between the lamina of that mem-
brane,  it descends  in a  direction which corresponds
with that of the root of the  mesentery,! and forms a
gentle  curve, with its convexity directed towards  the
intestines.  It necessarily diminishes as it descends,
and  generally terminates  by anastomosing with one
of its  own branches.—This great artery sends off
some very small ramifications  to the pancreas and
the duodenum, while it is in their vicinity.   It also
sends two or  three branches to the transverse part of
the colon, to the right portion of the colon, to the be-
ginning of the great intestine, and  the  contiguous
portion of the ileon.   These branches are commonly
termed the Colica Media, Colica Dextra,  and Ileo

  * It frequently happens that the splenic artery divides only into two or
three branches, and they subdivide so as to form five or six, which penei
trate the spleen.
  t Vol. n p. 115. 
       and the Inferior Mesenteric Arteries.   279

Colica.  From the  convex side of the  curve,  the
superior  mesenteric  sends  off the  important
branches which pass between the lamina of the me-
sentery,  and supply the  Small Intestines.  These
branches are numerous, and many of their ramifica-
tions  anastomose with  each other  so  as  to form
arches.  From these arches go off other branches,
which  anastomose again with some of similar origin;
and this process  is  repeated   successively several
times,  so that  a net-work of blood vessels  seems to
be formed on the mesentery.  From the mesentery
the small ramifications are continued in  great num-
bers to the intestines.   Some  of them  anastomose
with each other on the coats of the intestine; but an
immense number of  minute  arteries are continued to
the villous coat, so that, when they are  successfully
injected, the surface of that coat appears uniformly
coloured by the injection.*

    The INFERIOR MESENTERIC Artery

Does not go off from the aorta next in order after the
superior mesenteric, but succeeds it immediately on
the intestines, and continues the arterial ramifications
to the left portion of the eolon, to which the branches
of the superior mesenteric do not extend.
   This artery arises between the origin of the emul-
gents  and the great bifurcation of the aorta, and pro-
ceeds  downwards, inclining to  the left,  but keeping
near to the aorta. There are generally three branches
distributed to the left portion of the colon, which arise
from this artery, either separately, or by a common
trunk  which  soon divides.  It frequently happens,
that one of these arteries arises  separately, and two
by a  common trunk.   These  are called  the Left

  * See  the account of the termination of these arteries, at page 110 of
this volume. 
280     Emulgent and Capsular Arteries.
 Colic arteries; and are also sometimes denominated,
 from their position,  Superior, Middle, and Inferior.
 The  Superior  generally  anastomoses  with   that
 branch of the superior mesenteric,  which is called
 Colica Media, and forms a remarkable arch, called
 the Great Mesocolic Arch.  The ramifications of the
 other  branches  frequently anastomose with  each
 other, and are finally spent upon the left  portion of
 the colon.
   The main trunk, diminished by sending off these
 branches, but still of considerable size, runs down-
 wards on the posterior part of the intestine rectum,
 between that intestine and the sacrum, where it often
 divides into two branches, which continue near to
 the termination of the rectum.   From them proceed
 many ramifications that are  spent upon the rectum.
 Some of these  ramifications anastomose with  each
 other, and others with  the ramifications of the  he-
 morrhoidal artery, soon to be mentioned.
      The EMULGENT or RENAL Arteries
 Are the large vessels whieh pass  from the aorta to
 the kidneys.   They arise between the superior  and
 inferior mesenteries, oneftn each side; and proceed
 in a direction which is nearly rectangler  to  the
 aorta.   The right emulgent  artery is necessarily
 longer than the left,  and  it generally passes behind
 the vena cava.  When they approach near the con-
 cave edges of the kidneys, each emulgent commonly
 divides into three or four branches, which pass into
 the fissure of that organ, and ramify  in the manner
 described in the account of it.   Sometimes two arte-
ries proceed from the aorta to the kidney:  but this
is not a frequent occurrence.
              The Capsular Arteries
 Are the small vessels which pass to the  glandules 
         Adipose and Spermatic Arteries.      281

renales.  There are almost always several of them
appropriated to each gland.  They  often  arise on
each side from the cceliac artery, the aorta, and the
emulgent.
               The Adipose Arteries

Supply the adipose substance surrounding the kid-
neys.—There are several of them on each side, and,
like  the last mentioned arteries, they are very small,
and arise from several sources as well as the aorta.
  The testicles and ovaria are supplied by the

               Spermatic Arteries,

Which are very remarkable for their great length and
small diameter.  In a majority of cases these vessels
arise from the  anterior surface of the aorta, a little
below the emulgents : but it often happens that the
left spermatic arises from the  emulgent on  that side.
They also sometimes arise from  other neighbouring
arteries.  It has been observed when they arise from
the aorta, that the origin of one  of them is  generally
higher than that of the other.
  They pass downwards, so as to form an acute an-
gle with the aorta, and  proceed  behind the perito-
neum, and before the psoas muscle and ureter. While
this  artery is in contact with the psoas muscle, it
meets with the ramifications of  the spermatic vein,
and, in its progress to the abdominal ring, also joins
the spermatic cord.   In this course it sends off some
very small twigs to the contiguous parts, and  others
that anastomose with  similar ramifications  from the
mesenteric,  epigastric, &c.  Before it arrives at the
testicle, it divides into several branches, two of which
generally go  to the epididymis, and the others pene-
trate the upper and back part of the tunica albuginea
   Vol. ii.               36 
282            Spermatic Arteries.
      The Spermatic Arteries in the Female,
Instead of passing to the abdominal ring, proceed be-
tween  the lamina of the broad ligaments, and  send
branches to the ovaria, which, in some cases, may be
traced to the vesicles.   They also  send branches to
the fallopian tubes and uterus, and to the round  liga-
ments.  Those which are on the opposite sides of the
uterus,  anastomose with each other and with the
branches of the hypogastric arteries.
  The  lumbar regions are supplied with  arteries
which originate, like the intercostals, from the poste-
rior part of the aorta between the thorax and pelvis.
There are four or five of these vessels  on each  side,
and they are denominated

              The Lumbar Arteries.
They pass between the spine and the psoas muscles,
and send branches to the spinal cavity, to the muscles
of the lumbar regions, and  the  abdominal muscles.
They anastomose with the  internal mammary, the
epigastric, the circumflex of the ilium, &c.
  A small artery passes off singly from the posterior
part of the aorta at its bifurcation, which is called
           The Middle Sacral Artery.

It proceeds down the middle of the sacrum to the os
coccygis, and  sends off  lateral branches, which are
spent upon the contiguous parts, and inosculate  with
the arterise sacrse laterales. 
General Account of the Internal Iliac.   283
                   SECTION IV.

 Of the Arteries which originate at and below the
         Great Bifurcation of the Aorta.

            The PRIMITIVE ILIACS
Form an acute angle with each other.  They proceed
downwards behind the peritoneum, very  near  the
margin of the pelvis, without sending off any branch
of importance.  At the junction of the sacrum with
the ossa ilea, they divide into  two great branches :
the internal  iliac, or hypogastric, which  de-
scends  into the pelvis; and the external iliac,
which passes under the crural arch to  the lower ex-
tremity.
The  INTERNAL ILIAC, or HYPOGASTRIC,
Is distributed, in part, to the viscera of the pelvis and
the organs of generation, and also to the large mus-
cles exterior to the pelvis: it is, therefore, very large,
although not quite  equal to  the external  iliac.
  It has already been mentioned, that in the foetal
state, this vessel appeared  to continue in  a curved
direction from its origin to the lower part of the side
of the  bladder, and from thence to the Umbilicus,
under  the denominations of the Umbilical Artery.
From the convex  side of  this curve the different
branches of  the internal iliac go off.   In the foetal
state they are very small, in proportion to the umbi-
lical  artery; but as the artery becomes ligamentous,
these branches increase in size.
  In the adult, the arrangement of these  vessels is
very different.  The internal iliac generally di-
vides into two great branches:  the Gluteal, which
passes  through  the sacro sciatic notch, and ramifies 
284   Smaller Branches of the Internal Iliac.

on the exterior and upper part of the os ilium : and
the Ischiatic, which passes downwards on the outside
of the tuberosity of the ischium.
  The first of these large ramifications passes out of
the pelvis above the pyriform  muscle, and the last
of them below it.   Several smaller arteries arise from
these branches  near their origin,  or from the main
trunk of  the internal iliac, which are distributed to
the different parts of the pelvis; and one important
branch of the ischiatic, called the  Pudic, proceeds
downward on the inside of the  tuberosity of  the is-
chium.
  The first of the smaller branches which the inter-
nal iliac commonly sends off, is called the
                 Tleo Lumbalis:

It sometimes  arises from  the  gluteal artery, and
sometimes from the main  trunk of the internal iliac.
It passes  outwards under the psoas muscle, and sud-
denly, divides into two  branches.  One of them pro-
ceeds Upwards, and is distributed in the lumbar re-
gion, while the other ramifies on the illacus internus
muscle, and is spent on the contiguous parts.
  There are also  two or three small arteries called

            Arteria Sacrx Laterales,
Which 'sometimes  arise singly, and sometimes  in
common, from  the great trunk.    They also occa-
sionally originate  from the  gluteal artery.   These
vessels enter the anterior foramina of the os sacrum,
to be distributed on the cauda  equina and the mem-
branes which invest it.   Some of their ramifications
anastomose with  branches  of the sacra media and
other contiguous arteries.
  On the anterior side of the internal iliac, near the
origin of the above mentioned vessels, a  ligament
which was originally the umbilical artery, goes  off 
      Smaller Branches of the Internal Iliac.   285

to the side of the bladder, and continues from thence
to the umbilicus.  Sometimes it continues pervious
for a short distance,  and  then small  branches  pass
from it to the bladder.
  In  the female it also sends small branches to the
uterus and vagina.
   In addition to these Vesical Arteries derived from
the umbilicals, there are other branches distributed
to the bladder, which arise very differently, in dif-
ferent subjects,  from branches which are soon  to be
described, as the hsemorrhoidal, pudic,  &c.
   From the anterior side of the internal  iliac, or from
one of its great branches, an artery often arises which
passes out of the pelvis  through the aperture in the
margin  of the ligamentous  membrane  which  closes
the foramen thyroideum of the os innominatum; this
is called the
                 Obturator Artery.

This  vessel,  while it is  in the pelvis, often  sends
small  branches to the bladder and its appendages, and
to the obturator internus muscle.  After it passes out
of the pelvis, it frequently divides into branches;
some of which are spent on  the obturator externus,
and the contiguous muscles, and others go to the hip
joint.   The origin of this artery is variable.   Most
commonly it arises from the internal iliac,  but often
from  the ischiatic,  and  sometimes from the gluteal.
In some instances it originates in  a way that is par-
ticularly  interesting when the operation for crural
hernia is to be performed, viz. from the epigastric
artery,  soon to  be described:  for  in this case the ob-
turator artery sometimes  nearly surrounds  the neck
of the hernial sac*

  * See Astley Cooper's great work on Hernia, Vol. I.
  There is reason to believe  that this position of the artery occurs more
frequently than has been supposed. 
286  Larger Branches of the Internal Iliac.

   A small artery passes from the internal  iliac  or
one of its branches,  to the rectum, which is called
the
             Middle Hxmorrhoidal,
From its situation  between the branches which are
sent to that  intestine from the inferior mesenteric,
and those which go to it from the pudic.  This arte-
ry is spent upon that part of the rectum, which is
above and  in contact with the sphincter.  It sends
branches to the prostate  and vesiculse seminales  in
males, and the vagina and bladder in females.
   In females there is a peculiar artery,
                  The Uterine,
Which originates either from the internal iliac, near
the origin of the ischiatic, or from one of its branches.
It passes between the lamina of the broad ligaments
to the cervix uteri, and penetrates the texture of that
organ.  The size of this vessel varies with the vary-
ing size of the  uterus.
    The gluteal or posterior iliac Artery,
One of the two great branches of the  internal iliac,
proceeds exteriorly through the  sciatic notch above
the pyriform muscle, very near the edge of the bone.
On the outside of the ilium it generally divides into
two branches,  one of  which ramifies  between the
gluteus medius and minimus, and the other between
the medius and  maximus.  It is principally spent
upon these muscles, and sends branches to the conti-
guous parts.
             The ischiatic Artery,
The other great branch of the internal iliac, passes
through the sciatic notch below the pyriform muscle,
and proceeds downwards, between the  great tro-
chanter of the os femoris  and  the tuberosity of the
ischium, under  the gluteus maximus muscle.  Soon 
Pudic Artery.               287
after its orgin, it commonly sends off a considerable
branch, the Arteria Pudica, which also passes down-
wards :  it then continues its course as above mention-
ed, and its principal branches are' distributed to the
gluteus maximus and the muscles of the upper and
back part of the thigh, while its smaller branches go
to the os sacrum and  coccyx,  and  the contiguous
small muscles.
              ThePUDICA INTERNA,

As has been just mentioned, is often a branch of the
ischiatic artery, but sometimes originates immediately
from the internal iliac.   It proceeds downwards and
inwards, diverging from the ischiatic, and passing be-
tween the two sacro-sciatic ligaments  to the interior
side of  the tuberosity of the ischium, whence it con-
tinues on the inside of the crus of the os ischium and
pubis until it approaches the symphisis, when it gen-
erally divides into three branches, which are spent
upon the organs of  generation,  from which  circum-
stance the name of  this artery is derived.
   One or more branches from it also pass to the low-
er part of the rectum and sphincter ani, and are call-
ed the Lower Hxmorrhoidal Arteries.
   In its course it  sends off many small branches to
the contiguous parts; one of which, called the Peri-
neal, leaves it near the transversus perinei, and passes
between that muscle and the skin, and between the
bulb of the urethra and the crus of the penis, to the
scrotum.
   When the Pudic has arrived near the bulb of the
urethra it sends a branch into it, which is continued
into the corpus spongiosum urethras,  and ramifies
there minutely.
   At the symphisis of the pubis, it sends off a second
 branch, which passes to the back of each crus, and,
proceeding along it, parallel to its fellow? terminates 
 288 External Iliac.—Branches of the External Iliac.

 in the glans penis: in this course it sends branches to
 the elastic coat, to the integuments, and to the pre-
 puce.   This vessel is called the Arteria Dorsalis.
   The main trunk of the pudic artery then penetrates
 the corpus cavernosum, and proceeds through it in a
 straight direction. Its ramifications appear to be dis-
 tributed through the internal structure of the corpus
 cavernosum, and some of them extend  through the
 septum to the other side, while others  pass  to the
 corpus spongiosum urethras.

            The EXTERNAL ILIAC,

 The great  artery of the  lower extremity,  appears
 soon after birth, like a continuation of the primitive
 iliac, and proceeds along  the brim of the pelvis be-
 hind the  peritoneum, to  Poupart's ligament or the
 crural  arch, under which it passes.
  The psoas muscle  is  at  first in contact with it on
 the outside, and the  internal iliac vein on the inside.
 As it passes under Poiipart's  ligament, it is immedi-
 ately anterior to the  psoas  and  iliacus internus mus-
 cles where they are  united, and the crural nerve is
 exterior to it.   Before it arrives  at the lower edge
 of Poupart's ligament, it sends off

             The Epigastric Artery.

 Which arises on its internal side, and proceeds down-
 wards and inwards about half an inch,  then it turns
 upwards and inwards, and continues in that direction
for a small distance, after which its course is less ob-
lique.  It passes between the peritoneum and the ab-
dominal muscles, behind the spermatic cord, and the
round ligaments in females.
  It generally, changes its oblique direction after
 passing about two inches, and then proceeds in  con- 
     General Account of the Femoral Artery.  289

tact with the rectus, and very near its external edge.
Its  ramifications are expended upon the anterior pa-
rietes of the abdomen ;  and,  after it  has arrived as
high  as the  umbilicus,  it commonly divides  into
branches, which  often inosculate with the ramifica-
tions of the internal mammary.*
  An artery,  which is rather smaller than the epigas-
tric, arises nearly opposite to it,  but rather lower,
from the external side  of the  external  iliac.   It is
called

     The Circumflex Artery of the Os Ilium,

And proceeds upwards  and outwards to the upper
margin of the os ilium, along which it continues very
near to the spine.   It is distributed  principally to
the abdominal muscles, to the iliacus internus and the
psoas,  and the parts contiguous.
  The artery of the lower extremity,  after passing
under  Poupart's ligament, takes the name of

               FEMORAL Artery,

And  proceeds downwards in a direction  so spiral,
that although it is in front at the upper part of the
thigh, it is completely behind at the lower part.   It
sends  branches  to  the muscles of the thigh, as the
aorta does to  the viscera of the abdomen, viz.  by a
few large vessels which  extend and ramify to a great
distance among them.
  The situation of the  abductor muscles,  and their
attachment to the os femoris,  is such, that the artery
in this course must necessarily perforate their com-

  *  Several respectable surgeons have been taught by experience, that
when the abdomen is distended by ascites, the position of the epigastric
artery is so much altered, that it will sometimes  be found in the middle of
the oblique line, which extends from the umbilicus to the superior anterior
spine of the ilium.
  Vol, ii.               37 
290 Branches of the Profunda and the Femoral.

mon tendon, which  it does at the distance of one-
third of the length of the bone from its lower end.
The aperture in this tendon corresponds  precisely
with the general course of the artery; and before
the artery enters this perforation, it is on the inter-
nal side of  the bone; after it has  passed the perfo-
ration,  it  is on the  posterior side of it.   After
passing through  the tendon  of the abductors,  it is
denominated The Popliteal Artery,  and  it retains
this name until it divides.
   It then proceeds downwards, being very near the
bone, and between the tendons of the flexors of the
leg, covered by the great nerve of  the lower extre-
mity, and very often also by the vein.   After cross-
ing the articulation  of the knee, when it is between
the heads of the gastrocnemii muscles,  at the lower
edge of the popliteus muscle, it divides into the an-
terior tibial and the common trunk of the peroneal
and posterior tibial  arteries.
   The  femoral artery, soon after emerging  from
Poupart's ligament, sends off very small branches to
the inguinal glands, and  other contiguous parts.  It
also sends off the
                External Pudics9

Which are two or three small arteries that are gene-
rally spent upon the Scrotum in males, and the Labia
Pudendi in females.
   About two inches below Poupart's ligament, the
great  branch  which has  been called  the  muscular
artery of the  thigh, leaves it.  This vessel is  com-
monly denominated

               ARTERIA PROFUNDA.

It arises from the back part of the trunk of the femo-
ral, and passes downwards and backwards, in a way
that has been compared to the separation of the in- 
 Branches of the Profunda and the Femoral.  291

ternal iliac from  the external.   Very soon after its
origin, it sends off two branches, which proceed, one
on the internal, and the other on the external side of
the thigh, and are called the circumflexa interna and
externa.  It then passes downwards behind the trunk
of the femoral, and sometimes very near it, on the
adductor muscles, and finally divides into  branches,
which are called the Perforating.
            The External Circumflex
Sometimes arises from the femoral, but most common-
ly is a branch  of the profunda, as above stated.  It
passes under the rectus and  tensor vaginae  femoris
towards the great trochanter, and generally divides
into two  branches, one of which continues  in the
transverse direction, and sends branches to the upper
and back  part of the thigh, and the parts contiguous
to the joint; while the other descends in the course
of the rectus femoris muscle, and some of its ramifi-
cations extend near to the outside of  the knee.
              The Internal Circumflex

Is often smaller  than the other.   It generally passes
between the psoas, and the pectineus muscles,  and
continues round the thigh towards the lesser trochan-
ter.  Its ramifications are expended on the upper por-
tions of the adductor muscles and the muscular parts
contiguous to  the  lesser  trochanter.  It also  sends
branches  to the articulation.
             The Perforating Arteries

 Are two or three ramifications of the profunda, which
 pass through the adductor muscles, and are expended
 upon the flexor  muscles on the back of the thigh.
 Some of  the  terminating branches of the profunda
 itself are also called perforating arteries.
   The next branch of importance which  is sent ott 
292         Branches about the Ham.
by the femoral artery, leaves it before it enters the
aperture in the tendon of the adductors, and is called
            The Anastomotic Artery.
This vessel soon inclines downwards.   Its ramifica-
tions extends into the vastus internus muscle ; some
of them follow the tendon of the adductors, and ram-
ify about the internal condyle.
  Several small branches go off from the great artery
soon after it passes though  the tendon of the adduc-
tors, which are distributed  to  the  contiguous mus-
cles.  Some of them are also called
              Perforating Arteries.
Among  them is the principal Medullary artery of the
os femoris.
  In the ham, the  great vessel there called

                POPLITEAL,

generally sends off several small branches.   Two of
them go off on the  inside, one  above and the other
below the knee; and two on the outside in the same
manner. They are named, from their situation,  The
Superior and Inferior Internal, and The Superior
and Inferior External Articulary Arteries.
  The  Superior Internal artery perforates the ten-
don of the adductors above the  internal condyle, and
ramifies minutely on the inner side  of  the joint.
   The  Superior External artery passes through the
lower portion of the biceps above the external condyle,
and ramifies minutely on the outer side of the joint.
Its superior ramifications anastomose with those of
 the descending branch of the  external  circumflex,
 while its inferior  ramifications  communicate  with
 those of the corresponding artery below.
   The two inferior arteries  originate nearly opposite
 to  the middle of the joint, and pass downwards.
   The  Inferior Internal artery passes  under the 
Artery of the Leg.            293
internal head of the gastrocnemius muscle, on the
posterior and internal side of the  head of  the tibia.
Its ramifications communicate with those of the cor-
responding artery above and of the tibialis antica.—
Below they also extend to the interior of the joint.
  The Inferior External artery  passes  under the
external head of the gastrocnemius and the plantaris
muscle, and continues under the external lateral and
the capsular ligament.   It is distributed on the ex-
ternal and inferior part of the articulation, and sends
also some branches to the interior of the joint.
  There is frequently an azygous  vessel,  called the
Middle Articular artery, which arises from the back
of the popliteal, and is distributed to  the posterior
part of the articulation.
  The popliteal artery, after this, sends off a few
small branches to the heads of the muscles of the leg,
and among them one of  considerable length,  to each
of the heads of the gastrocnemii.   At  the under
edge of the popliteus muscle, it sends off horizon-
tally a large  branch which passes directly forward
between the tibia and fibula, above the commence-
ment of the interosseous ligament.   After this it con-
tinues to descend, nearly in the  same direction, un-
der the soleus muscle, behind the tibia; but before
it has proceeded further than twelve or fifteen lines,
it sends off a branch  which forms an acute angle with
it, and approaches near the fibula, along which it de-
scends.
  The branch sent off anteriorly, is called the Ante-
rior Tibial artery.
  The main trunk,  which continues downwards, is
called the Posterior  Tibial artery;
  And the branch which  descends near the fibula is
called the Peroneal or Fibular artery. 
 294       Anterior Artery of the Leg.


           The anterior tibial Artery,

 After its arrival on  the anterior part of the leg, pass-
 es down close to the interosseous ligament, with the
 tibialis anticus muscle on the inside, and the extensor
 communis on the outside,  in  the  first part of  its
 course; and afterwards,  with  the extensor pollicis
 pedis on the outside of it.  It gradually inclines in-
 ternally as it descends, so that a little above the ankle
 it is  upon the  front part of the tibia.  It proceeds
 thence with the tendons of the extensor digitorum
 pedis, under the annular ligament, to the upper sur-
 face of the foot, on  which it continues  to  the inter-
 stice  of the first and second metatarsal  bones, where
 it descends to anastomose in the way presently to be
 mentioned.
   In  this course it sends off, soon after it has arrived
 at its anterior  situation, a recurrent branch, which
 is distributed to the heads of the  muscles and  the
 ligaments of  the articulation, and which anastomoses
 with  the  branches of the inferior articular arteries.
 It also sends off, on each side, many arterial  twigs
 to the contiguous muscles, and  very frequently one
 branch of considerable size, which passes down near
the fibula.
   When it has arrived near the end of the tibia, it
 sends a branch on each side, called  the Internal and
External Malleolar. On the top of the foot, among
several smaller arteries, it sends off  a branch under
the extensor brevis digitorum pedis, which passes out-
wards and forwards,  and supplies the muscles, &c.
on the upper part of the foot.   This vessel is called
Arteria Tarsea. There is also another branch,  call-
ed Metatarsea, which generally arises about the mid-
dle of the foot, and passes obliquely outward and for-
ward, supplying the  contiguous parts. 
     Posterior Tibial and Peroneal Arteries.  295

  The Anterior Tibial artery, having arrived at the
space between the metatarsal  bones of the first and
second toes, bends down to the sole of the foot, but
previously sends off a branch which passes near the
external edge of the metatarsal bone of the great toe,
and divides into two branches, one of which goes to
the outside of the great toe, and the other to the op-
posite side of the toe next to it.
           The posterior tibial Artery,

After sending off the anterior tibial, parts with the
Peroneal or Fibular, as has been already stated, and
then continues  on the back of the  tibia,  behind the
internal ankle,  to the sole  of the foot.
          The  Peroneal or Fibular Artery

Is not commonly so large as either of the two other
arteries of the  leg, nor is it so  constant.  It passes
down very near the internal edge of the fibula.  It
is in contact, for some distance, with the  tibialis pos-
ticus muscle, and is anterior to the soleus  and the
flexor pollicis  longus;  it  sends  branches to the
 contiguous muscles.  After it has passed along two-
thirds of the length of the fibula, it frequently, but
not always, divides into an anterior and  a posterior
branch.
   The anterior peroneal soon perforates  the interos-
 seous ligament, and passing down some  distance  on
 its anterior surface, continues to the ankle and upper
 surface of the  foot.  It gives ramifications to all the
 contiguous parts  in its  progress,  and  anastomoses
 with some of  the  small  ramifications of the tibialis
antica.
   The posterior peroneal branch is the continuation
 of] the main trunk.  It passes behind the  external
 malleolus, and  ramifies upon the external side of the
 foot. 
296            Arteries of the Foot.
   The posterior tibial artery passes down, inclining
rether obliquely  inwards,  between the  gastrocne-
mius internus, which is posterior to it, and the tibia-
lis posticus and flexor digitorum, which are anterior
to it.   Upon the leg it gives off many small branches,
one of which, termed  the  Arteria Nutritia Tibix,
comes off high up,* and,  after  ramifying as  it de-
scends,  sends a branch to the medullary foramen  of
the tibia.
   At the lower part of the leg the Posterior Tibial,
is situated rather superficially between  the  tendo
Achillis and  the  tibia.   It proceeds thence behind
the internal ankle in a  deep situation, covered by an
annular ligament, and  passes between the abductor
muscle of the great toe and the  bones of  the tarsus.
It then divides into two branches—the internal and
the external plantar arteries.

           The Internal Plantar Artery

Is commonly much smaller than  the other ramifica-
tion.  It passes in the direction of the internal edge
of the foot, but at some distance from it, and often
lies between the aponeurosis plantaris and the ab-
ductor pollicis.   It frequently terminates  by anasto-
mosing with one of the arteries of the great toe, and
in its course sends off several branches to the conti-
guous parts on each side of it.

           The External Plantar Artery

Is the continuation of the main trunk.  It proceeds
outwards and forwards between  the short flexor  of
the toes and the  flexor accessorius; and continues
afterwards between the first of these muscles and the
abductor of the little toe.   At the metatarsal bone of
* This artery sometimes comes off from the popliteal 
               Arteries of the Foot.           297

 the little toe it begins to curve, and continues its cur-
 vature across the other metatarsal bones to the inter-
 stice between the great toe and  the one next to it,
passing between the tendons of the long extensor and
 the metatarsal bones.  At the interstice above mention-
 ed, it anastomoses with the tibialis antica.  The cur-
 vature, thus formed, is called the Arcus Plantaris.
   In this course, the External Plantar sends off se-
 veral branches, to the  heel and the parts of the  foot,
 especially on the external side; the deep-seated parts
 of the foot being supplied from the curve.
   Digital branches go  off from the curve, as they do
 in the hand, from the curve of the ulnar.  There is
 first a small branch to the outside of the little  toe;
 and then three regular branches, which pass  to the
junction of the roots of the four small toes, and divide,
 like the digital arteries of the hand, so  as to  send a
 branch to the side of each toe.  These digital arteries
 pass between the musde called Transversalis Pedis
and the metatarsal bones.  Near the heads of these
bones, each of them generally sends off  two arteries
that pass upwards between the interossei muscles and
the bones, and anastomose with the ramifications from
the top of  the foot.
   The External Plantar, soon after sending  off the
third  digital artery,  anastomoses  with  the anterior
tibial, and  then continues to the junction of the  root
of the great toe with the one next to it, when it di-
vides  into  two branches, which go  to  the opposite
sides of those toes.  In  its course it also sends a branch
to the internal' side of  the great toe.
Vol, ii.
38 
CHAPTER III.
  OF THE PARTICULAR DISTRIBUTION OF THE VEINS.

  Anatomists of great respectability have very dif-
ferent sentiments respecting the best method of de-
scribing the veins. Some of them, in order to follow
the course of the circulation, commence with the small
veins, and  proceed  to the large trunks which are
formed by their union. Others begin with the great
veins that empty into  the  heart, and proceed from
them to the small ramifications of the venous system,
in a direction the reverse of the circulation.
  As the last method is the easiest for the student of
anatomy, it will be adopted here ; but it must always
be kept in mind, that  the blood flows from the small
veins into the larger, and not from the latter into the
former, as the mode of description seems to imply.
  The great trunk of  the venous system differs con-
siderably from that of the  arterial  with  respect to
its connexion with the heart;  for it communicates
with that organ in such a manner that, when viewed
from before, it appears like two vessels ; one open-
ing into the upper, and the other into the lower part
of the  right auricle.   When viewed from behind, it
appears like a continued tube, three-fourths of which
are deficient anteriorly;  and  to the margin of this
deficiency the right sinus  or pouch of the heart is
connected.
  In some preparations of the heart, where all the
great vessels connected with it are  much distended
by  the injection, and the pulmonary vessels are  in- 
             The Veiv>s of iitt Heart,          299

jected first,  the  right auricle  is so much pressed
upon from behind,  by the vessels which go  to the
right lung, that the direction of the superior and in-
ferior portions  of the vena cava, which thus commu-
nicate with it,  is altered.   Each of them  is turned
obliquely forwards,  so  that it forms an angle with
the other.  This occasions them to appear more like
distinct vessels than  they otherwise would do.
   The above mentioned portions of the great veins
are denominated the  Superior or Descending, and the
Inferior or Ascending  Vena Cava ; as if they were
perfectly distinct and unconnected with each other.

               The coronary Veins,

Which  are  exclusively appropriated  to the  heart,
may be considered here, as they are not included in
the general arrangement of the veins.
   The great vein of the heart  begins  at the  lower
part of the right  auricle, very near to the septum,
which divides  the two auricles.   It soon proceeds to
the left in a circular direction, surrounded with adi-
pose matter, in the deep groove which exists between
the left auricle and the left ventricle.   It continues
between the auricle  and ventricle,  until it is  imme-
diately over  the septum, which divides the two ven-
tricles.   Here its direction changes, and it proceeds
to the apex of the heart, where its small ramifications
anastomose with others soon to be described.   In its
course round the basis of the left ventricle, it sends
off several branches, one  of which is  considerable,
that proceed from the basis towards the apex of the
heart, ramifying on  the surface of the left ventricle.
   A second vein, much less than the  first, appears
to proceed  from  the great vessel  at its commence-
ment,* and  continues on  the lower flat surface  of
* It often opens into the auricle by a separate orifice. 
600 Superior Vena Cava and its Great Branches.

the heart, between the  two ventricles,  to the apex,
accompanied by a branch of the right  coronary ar-
tery.  This has been called the Middle Vein of  the
heart.
  In addition to these there are several veins which
begin at the right auricle, and extend on the surface
of the right ventricle towards the apex  of the heart.
These have been called the Anterior Veins.

                    SECTION I.

 Of  the SUPERIOR or DESCENDING VENA CAVA,
        and the Veins which communicate with it.

  This great vessel proceeds  upwards  from   the
superior and posterior  part of the  right  sinus or
pouch of the heart ;* and a portion of it is so involv-
ed by the pericardium, that it seems to be included in
that sac, as the heart is  in this situation.  It is some-
what anterior as well as to  the right of the aorta.  It
continues  above  the pericardium,  adhering to  the
right lamen of the mediastinum, and rather inclining
forward.  When it is as high as the lower margin
of the upper rib, it sends off  a very large branch,
which conveys the venous blood of  the  left arm and
the left side of the head and neck.  This large vein,
which is very important, both  on account of its size
and its situation,  proceeds in a  transverse direction
within the sternum, almost in contact with  and  but
little below the  upper and internal  margin of that
bone.  Immediately behind or within  the origin of
the left sterno-mastoid  muscle, it  divides  into  the
left subclavian, which preserves a transverse course,
and  the left internal jugular, which proceeds to  the
cavity of the cranium by the foramen lacerum.
  After sending off this transverse branch to the left,
* See the description of the heart,, in page 51, of this volume. 
Vena Azygos.               301
the great vein continues upwards and behind the
right sterno-mastoid muscle, and there sends off, near-
ly at right angles, the right subclavian vein.   After
it has parted with this vein, it takes the name of In-
ternal Jugular, and continues to the right foramen
lacerum, in the basis of the cranium.   The superior
vena  cava is,  therefore, principally formed  by the
union of the subclavians and internal jugulars from
each side of the body.
  Immediately after the superior  cava rises above
the pericardium,  before it divides as above stated, it
sends  off, from its posterior part, a  large vein which
is single, and therefore called

                  vena azygos.

  This  vessel  projects backward  above  the right
pulmonary artery and  right branch of the trachea,
and then curves downwards behind them.  It pro-
ceeds down the spine to the right of the aorta and at
a small distance frOm it, into the abdomen, between
the crura of the diaphragm, and sometimes between
some of the portions of that muscle, which  are at-
tached to the  dorsal vertebras.  In the abdomen it
often  anastomoses either with the  lumbar veins or
the vena cava.
  The  azygos frequently sends off several small
veins  from its  curvature to the contiguous  parts, and
also the right Bronchial Vein,  which passes along
the ramifications of the trachea into the substance of
the lungs.*  In  its course  downwards it gives off
branches to the oesophagus, some of which are consi-
derable.
  The Inferior Intercostal  Veins originate directly
or indirectly from the  azygos.   In  some cases there
is no  Superior Intercostal on the right side; and then
* This bronchial vein sometimes arises from the superior cava, 
302         Inferior intercostal Veins.
the two or three uppermost of the right intercostals,
are also derived from  the azygos ;  and often origi-
nate from it by a common trunk, which soon divides.
Most commonly the ten inferior  intercostals on the
right side proceed directly from the azygos, and ac-
company the  intercostal arteries.  Their posterior
branches pass into the  vertebral cavity, and commu-
nicate with the veins which are there.
   About the sixth or seventh rib,  the vena azygos
frequently sends off a branch  to  the  left  which de-
scends on the left side  of the vertebra, and sends off
those Left intercostal veins which are below its ori-
gin. It passes through  the diaphragm with the aorta,
or to the left of it, and anastomoses either with the
azygos itself,  or in a way which is  analogous to the
anastomosis of that vessel.
   The Vena Azygos may be regarded as the great
trunk of the  veins of the parietes of the thorax,
which are thus collected, because they  could not
with convenience pass  singly to the  vena cava, as the
arteries do to  the aorta.
   Soon after sending off the vena azygos,  the Supe-
rior Cava sends off the great  transverse  branch
above mentioned.  From  this it continues upwards
but a short distance, when it divides, behind the
right sterno-mastoid muscle,  into the right subcla-
vian and  right internal jugular.
  The branches of the superior cava, which thus
intervene between the great  trunk and the subdi-
visions behind the sterno-mastoid muscles, are often
called the Subclavian Veins ; but they do not appear
to be accurately named. For, 1st, they are not situ-
ated under the clavicle, and, 2dly, they are the com-
mon trunks of the subclavians and internal jugulars
united.
  There is a difference in the places where some of
the smaller veins originate on each side. The inter- 
            Superior Intercostal Veins.        303

nal mammary and the inferior thyroid, on the right
side, arise from the superior  cava,  or from the sub-
clavian at its origin.  On the left side they arise from
the subclavian.
        The superior  intercostal  Veins

Are somewhat different on the two  sides.  That on
the right is often the smallest and  the least  exten-
sive.  It commonly originates from the posterior and
inferior part of the subclavian opposite to the origin
of the vertebral, and is generally distributed to the
first and second intercostal spaces, but rarely to the
third.
   The Left Intercostal frequently originates near the
left internal mammary, and sometimes  in common
with it.  It descends behind the aorta, on the left of
the spine, and commonly sends off the six upper  in-
tercostal veins, of which the two  or three superior
pass upwards from a part of the vein which is oppo-
site to the  third dorsal  vertebra.  Its extent is very
different in different subjects.   In some  instances it
passes so low as to supply the seventh or eighth  in-
tercostal space.  This vein also gives off the Left
Bronchial Vein, which sends  branches  to the ceso-
phagus and bronchial glands.

               The vertebral Veins

Arise from the subclavians, but sometimes they pro-
ceed  differently in different subjects : the right pass-
ing behind, and the left before, the  subclavian artery
of its respective side.  Each of them, however,  be-
comes contiguous to its corresponding artery.  When
it has arrived at the place in the transverse processes,
where the  artery enters the vertebral canal,  it sends
off an external branch, which passes up, before and
nearly in contact  with, those. processes, and  gives
ramifications to the contiguous  muscles,  and also to 
304
Vertebral Veins.
 the cavity of the spine.  These last mentioned, rami-
 fications enter by the lateral apertures between the
 transverse processes, and anastomose with the veins
 and sinuses of the cavity.  The branch often finally
 terminates in the lateral sinus of the dura mater, by
 passing through the foramen near the mastoid process
 of the temporal  bone.  The Main Trunk of the ver-
 tebral vein generally sends off another external branch
 to the muscles near the basis of the neck, and after-
 wards enters  the  canal with the  vertebral  artery.
 While in this canal it generally sends off two branches
 through each of the lateral apertures between the ver-
 tebrae.   One of  these branches passes  backwards to
 the muscles of the neck, and the other proceeds into
 the great spinal  cavity,  and  communicates with  the
 venous sinuses.
  When  it  has arrived at  the atlas,  the  Vertebral
 vein sends branches to the contiguous muscles of the
 neck.   It also frequently sends a branch through the
 posterior condyloid foramen of the  occipital  bone to
 the lateral sinus.
  It is  evident, from these  circumstances that  the
 vertebral vein carries a portion of blood  from the
 sinuses  of the brain and  of the spinal marrow, as
 well as from the muscles of the neck,  into the sub-
clavian veins.
  The veins of the head are .frequently very differ-
ent in different subjects.

         The INTERNAL JUGULAR,

Already mentioned,  is  often almost exclusively ap-
propriated to the cavity of the cranium; and all the
exterior veins of the head are ramifications of one or
more  smaller vessels, which pass up superficially on
the neck, and are denominated External Jugulars.
In some instances almost all the exterior veins of the
head are united to  the internal jugular at the upper 
               The Internal Jugular.           305

part of the neck, and it of course conveys the blood
of the exterior as well as of the interior parts of the
head.   Frequently these veins are divided between
the internal and external jugulars, but they are di-
vided very differently in different subjects.
  The  Internal Jugular,  however,  almost always
passes in the same direction from the inside  of the
origin of the sterno - mastoid muscle to the posterior
foramen lacerum of  the cranium.  It is deeply  seat-
ed on the external side of the common carotid artery,
and under the  sterno-mastoid muscle.   Between the
upper margin of the thyroid cartilage and the angle
of the lower jaw, it often sends off branches which
are very different in different subjects, but commonly
pass to  the anterior parts of   the neck and face :
above these it generally sends  another  to  communi-
cate with the external jugular.  One of the branches
which often go off from the internal jugular is  that
which corresponds with the superior  thyroid  or la-
ryngeal  artery.   This vein,  which  has sometimes
been called the Guttural,  sends many ramifications
to the  thyroid gland.   The Ranular veins,  which
are so conspicuous under the tongue, are also derived
from it; and it likewise sends branches to the larynx
and pharynx.
  Before the internal jugular  enters the foramen la-
cerum,  it suffers a partial dilatation, which is gener-
rally larger on  one side than the other.*  This  dila-
tation occupies the  fossa  at the  foramen lacerum.
After passing through the aforesaid foramen, the in-
ternal jugular terminates in the lateral sinuses of the

  * When  the veins of the neck are injected, it very often appears  that a
considerable portion of the internal jugular  is much larger on one side than
the other, as if it were affected with varicose distention.
  It also often appears that the general arrangement of the exterior vein is
different on the two sides of the head and neck.
  Vol. ii.               39 
306           The External Jugular.
dura mater.*   These and the  other sinuses within
the cavity of the cranium are important portions of
the venous system, which are interposed between the
smaller branches spread upon the pia mater and the
great trunks of the  neck.  They are described in
the account of the brain, (Vol.  I. page 316.)  Into
these  sinuses the  very  numerous veins of  the pia
mater open, proceeding to the sinuses in a direction
the reverse of that in which the blood flows  in those
channels.
  These veins are divided very minutely on the pia
mater before they enter the substance of the brain.
  Into one of these  sinuses,  denominated the  Ca-
vernous, the ophthalmic vein discharges its contents.
This vein proceeds from  the anterior part of the
sinus into the orbit of the eye through the sphenoid
fissure.f  Its ramifications correspond  generally with
those of the ophthalmic artery! and some  of  them
pass out of the orbit to anastomose with the branches
of the facial vein.
  The superficial veins of the  neck are variously
arranged in different  persons.   There is often one
considerable vein,

         The EXTERNAL  JUGULAR,

Which is  sent  off by the  subclavian, very  near its
union with the  internal jugular; but sometimes it
goes off from that vein much  nearer the shoulder.
There are sometimes two external jugulars,  an  ante-

  * It is asserted that the internal coat, or lining  membrane of the inter-
nal jugulars, is continued into the lateral sinuses, and extends throughout
all the sinuses of the dura mater; so that the blood, during its  passage
through the sinuses, does not come in contact with any membrane different
from that of the veins.
  t See the account of this fissure in vol. i. p. 63.
  % The Vasa Vorticosa of the choroides are one of the exceptions to this.
See vol. i. p. 350. 
General Account of the Great Vein of the Arm. 307

rior and a posterior, nearly of equal size.  More fre-
quently one of them is much smaller than the other.
In a majority of cases,  the principal external jugular
goes off near the junction of the internal jugular and
subclavian, as above stated,  and  proceeds upwards
towards the angle of the lower jaw, passing between
the platysma myoides and the sterno-mastoid muscle.
It often sends off, at the basis of the neck, one or more
branches to the contiguous muscles, and then proceeds
upwards.   Near the angle of the jaw, it often com-
municates with the internal jugular : it then continues
upwards, covered with the parotid gland, near the
temporal artery,  and finally divides into  superficial
and deep-seated temporal branches.
   The  External Jugular, near the angle of the jaw,
often sends off the facial vein, which crosses the basis
of the lower jaw, near the facial artery,  and  distri-
butes branches to the side of the face and to the fore-
head.   It also very often sends off,  near this place,
the internal maxillary  vein, which generally ramifies
in such a manner that  its  branches correspond with
those of the internal maxillary artery.  Veins which
correspond to some of the other branches of the exter-
nal carotid artery, the lingual, occipital,  &c. are of-
ten sent off near this place by the external jugular.
They take  the  names of the arteries to which they
correspond, and commonly accompany them.
            Tlie SUBCLAVIAN Vein,

Although it originates differently on the  two sides of
the neck,  is situated alike on each of them.   After
parting with the internal jugular, it proceeds over
the first rib, under the clavicle,  and does not pass
between the scaleni muscles, as is the case with the
arteries, but before  the anterior muscle.  It soon
joins the great artery  of the arm, and proceeds be-
fore or below it to the axilla. In this situation it gives 
308 General Account of the Great Vein of the Arm.

off branches to the contiguous parts, which correspond
with those given off by the artery.   In this course
it also often gives off a large branch, called the
                   cephalic,
Which soon becomes superficial, and proceeds down-
wards between the margins of the deltoid and pecto-
ral muscles :  it continues superficial on the external
side of the biceps muscle, sending off many subcuta-
neous branches.  Near the external condyle of the os
humeri, it generally sends off a branch towards the
middle of the anterior part  of the fore-arm, which is
called the Median Cephalic, and also some other su-
perficial  branches.  It then  continues over the radius,
and inclining to the back of the fore-arm, until it ar-
rives at the back of the hand, where it divides into
branches, some of  which go to the thumb.
  In the axilla, the great vein, there called
             The AXILLARY Vein,
Generally divides into two or three branches.  One,
which is  commonly the largest, and appears like the
continuation of the main trunk, is called
                The basilic  Vein.
This vessel passes down, deeply seated, to the bend
of the elbow.  It becomes superficial near the inter-
nal condyle, and divides into several branches.—One
of these generally proceeds to join the median branch
of  the cephalic,  and from  the  union of  the  two
branches is formed the median vein, which passes
down near the middle of the anterior part of the fore-
arm.   This vein generally sends off a branch which
proceeds internally, and anastomoses with the deep-
seated veins of the fore arm.
   There are frequently two  other branches of the
basilic vein.  One, which  is small, passes down on 
       Situation of the Inferior Vena Cava.   30$

the ulnar side of the anterior part of the fore-arm,
but does not extend to the wrist.  The other passes
down on the ulna, and gradually proceeds  to  the
back  of the  hand, when  it divides into  several
branches, one of which is generally appropriated to
the little finger.
  The  axillary  vein, after the Basilic leaves it,
sometimes divides into two branches,  and sometimes
continues undivided.  In either case  it accompanies
the humeral artery, and takes the name of humeral
 Vein or Veins.  It sends off branches which  corres-
pond to those of the artery, and continues to the bend
of the elbow ; here it is so  divided, that two of its
ramifications accompany each of the three arteries of
the fore-arm.  These  ramifications sometimes com-
municate with each other by anastomosing branches
near the elbow, and they communicate also with the
superficial veins.

    The superficial veins of the arm  are so different in dif-
      ferent subjects, that a general  description will rarely
      apply accurately to an individual case.   It may,  how-
      ever, be observed, that a Cephalic vein will generally
      be found, which very frequently arises  from  the sub-
      clavian instead of the axillary, and commonly conti-
      nues to the hand on the radial side of the arm.  The
      superficial veins, on the  ulnar side of the fore-arm,
      very frequently are branches of a large vein which ac-
      companies the humeral artery to the elbow, viz. the
      basilic; but the median vein, formed by branches of
      the cephalic and basilic veins,  is very often not to be
      found.

                     section ii.

 Of the INFERIOR VENA CAVA, and the Veins
            which are connected with it.

   This great vessel exceeds the Superior Cava in
 diameter.  It proceeds from the lower part of the 
310   Situation of the Inferior Vena Cava.

right auricle, and  very soon  perforates  the  dia-
phragm, at a small distance in front  of the spine,
and rather to the right of the centre.  As the peri-
cardium adheres to the  diaphragm at this place, the
vessel  appears  to  leave it abruptly.   Immediately
after leaving the diaphragm,  it  proceeds along a
groove in the posterior edge of the liver, formed by
the great lobe and the lobulus Spigelii.*    After
leaving the liver, it continues downwards, inclining
backward and to the left, and is soon in contact with
the aorta, which is on the left of it.   It accompanies
the aorta to its  great bifurcation, and divides in the
same manner.   It sends  off,  during this  course,
branches  to  the Diaphragm,  Liver,  Right  Renal
Gland,  the  Kidneys,  and  the  testicles;  and  also
the Lumbar and Middle Sacral veins.

            The Inferior Phrenic Veins

Are thus denominated to distinguish them from other
veins, which are derived from the internal mammary,
&c.  They generally accompany the phrenic arteries,
and are distributed in the same manner.

                The hepatic Veins

Pass off from the vena cava, nearly at right angles,
into  the substance of the  liver, while it  is  in the
groove of that  viscus, and  before it has proceeded
more than eight or ten lines from the heart.
  They arise from the anterior part of  the vena
cava,  and are generally three  in number.   Some-
times there  are  two only,  but then one of them di-
vides immediately after it enters the substance of the
gland.
  The distribution of these vessels  in  the  liver has
* Sometimes It is completely surrounded by the liver. 
       The  Vena Portarum.—Splenic Vein.   311

been detailed in the account of that organ, and there-
fore need not be stated here ;  but the veins which
unite to form the vena portarum, and the trunk of
that great vein also,  before it is connected with the
liver,  may be regarded as a portion of the regular
venous system, and ought nowvto be considered.

            The VENA PORTARUM

Passes downwards from the  great sinus of the liver
behind the pancreas, and inclining to the left. In this
course it sends branches to the gall bladder, the sto-
mach and pylorus, and the duodenum.   At the up-
per and posterior edge of the pancreas,  it  sends off
a very large branch to the spleen, which often pass-
es, with slight meanders, along a groove in  the pan-
creas.
              The SPLENIC  Vein

Often sends off the  inferior  mesenteric  vein,
which proceeds  downwards  between the aorta and
the left portion of the colon.  It also sends off some
of the  coronary veins and  the  left gastro epiploic
vein to the stomach ;  many small branches to the pan-
creas ;  and,  finally,  either from  the main  trunk or
its branches before they enter  the spleen,  the  vense
breves, which pass to the great extremity of the sto-
mach.   Before it enters the spleen, it forms several
ramifications, which accompany the branches of  the
splenic artery.
   After sending off the splenic, the Vena Portarum
takes the name of

    The SUPERIOR MESENTERIC  Vein;

Which is larger than the splenic, and  passes  from
behind the pancreas, before the transverse portion of 
 312 Superior Mesenteric Vein.—Emulgent Veins.

 the duodenum, into the mesentery; where it accom-
 panies the superior mesenteric artery.
   It is evident that the above described portion of
 the vena portarum simply performs the functions of
 a great vein; but when it takes on the arrangements
 for entering the liver, it no longer acts like a vein,
 but an artery.
   The lower portion  of the trunk of this vein and its
 ramifications is denominated Vena Portx Ventralis.
 The part which ramifies in the liver, Vena Portx
 Hepatica,
               The Capsular Veins

 Are small vessels, one on each side.  That on  the
 right  passes from the  vena cava to the right glandula
 renalis.   That on the left arises from the left emul-
 gent vein.

      The EMULGENT, or RENAL Veins,

 Are very large vessels; and, like the arteries, go off
 nearly at right angles, one to each kidney.
  The right emulgent vein is not so long as the left,
 and it is rather anterior to its corresponding artery.
 The left emulgent, in  its course to the kidney, cross-
 es the aorta, and is anterior to it.
  These veins pass to the sinus of  each kidney, and
ramify before they enter it.  The  ramifications  fol-
lows those of the arteries.
              The Spermatic Veins

Arise one on each side: the right from the vena cava
and the left from the emulgent vein.  They proceed
downwards behind the peritoneum, and on the  psoas
 muscle generally divide into  many branches which
communicate with each other as they progress down-
wards, and form  a  plexus  denominated  Corpus
 Pampiniforme.    These branches  proceed in the 
       Internal Iliac and its Ramifications.    313

 spermatic cord to the back of the testis.   The prin-
 cipal part enters the body of that gland; but some of
 the branches go to  the epididymis.  In females the
 spermatic vein, like the artery, passes to the  ovary,
 the uterus and its appendages, &c.

                The Lumbar Veins

 Correspond  to the arteries of the same name.  They
 arise from the posterior and lateral parts of the in-
 ferior cava,  and  those on the left side pass under the
 aorta.
              The Middle Sacral Vein

 Resembles the artery of the same name in its origin
 and distribution.
  The INFERIOR VENA  CAVA accompanies
 the aorta to the  space between  the  fourth and  fifth
 lumbar vertebrae, and there it also divides  into  the
 two
          PRIMITIVE ILIAC VEINS.

 The left vein crosses behind the artery of the right
 side, and rather behind the left primitive iliac artery,
 which it accompanies until they are opposite  to the
junction of  the  sacrum  and ilium, when it divides
 again, like  the artery, into the internal  and  exter-
 nal iliac veins.

 The INTERNAL ILIAC, or HYPOGASTRIC
                      Vein
 Descends into the pelvis behind the artery,  which it
accompanies.  Its ramifications correspond in  gene-
ral with those of the artery, and, therefore, need not
be particularly described.

             The VEN2E VESICALES

Have such peculiarities that  their ramifications re-
quire particular attention.   They arise from the hy-
  Vol. ii.             40 
314   Ramifications of the External Iliac.

pogastric, very near the origin of the obturator, and
are large as well as numerous.
  They are somewhat different in the two sexes.   In
men they form a remarkable  plexus  on the lateral
and inferior portions of the bladder, and on the ve-
siculae seminales.   This plexus extends more or less
to the prostate: from it a number of veins proceed to
the symphisis of the os pubis,  which communicate in
their course with the pudic  vein.    From thence
arises the great vein of the penis, which proceeds in
the groove between the corpora cavernosa, and  ter-
minates in the glans penis.   This vein often divides,
near the root of the penis, into two: one of which is
in the groove, and the other more superficial.*
  In females, the venae vesicales form a considerable
plexus on each  side of the bladder  and vagina.—
Many veins pass from these  to  the upper portions
of the bladder and the contiguous parts, and form
plexuses.  The clitoris  has a dorsal  vein  like  the
penis, and it originates in a manner analogous to the
dorsal vein of  the male.

        The EXTERNAL ILIAC Vein.

The great trunk of the veins of the lower extremity
proceeds on the inside of the artery, under the crural
arch or Poupart's ligament.   Before it passes from
under the arch, it sends off two branches which an-
swer to the circumflex artery  of the ilium and to the
epigastric artery.

               The Circumflex Vein

Arises from the external side of the iliac  vein,  and
passes towards the anterior end of the spine of the

  * The pudic veins accompany the arteries of that name, They com-
municate with the plexus, as above mentioned, and continue into tha
penis. 
Veins of the Leg.             315
ilium.   It divides into  branches which accompany
those of the artery of the same name.

               The Epigastric  Vein

Arises from  the external iliac, and accompanies  the
epigastric artery.—After passing a small distance in-
ward and downward, it  turns up on the inside of the
abdominal muscles.    In the first  part of its course
it  sends off  some small branches to  the  spermatic
cord.    .
  After  passing  beyond Poupart's  ligament  the
name of the great vessel is changed  from external
iliac to
              FEMORAL VEIN.

It proceeds  downwards  at first on the inside of  the
femoral artery,  but  gradually  changes its  relative
situation, so that in the  thigh and in the ham it is
behind or on the outside of that vessel.
  At a short distance below Poupart's ligament, af-
ter giving off some small branches to the external or-
gans of  generation, and  to the glands of the groin, it
sends off on  the  internal side of the thigh a very
large vein which is called the

                 SAPHENA MAJOR.

This vein  immediately becomes superficial,  and
passes down on the internal side of the thigh, some-
what anteriorly;  giving off some small branches to
the  contiguous parts, soon  after it originates; and
many superficial veins afterwards.  It continues along
the inside of the knee and leg to the internal ankle,
the anterior part of which it  passes over.  It then
proceeds along the internal part of the upper surface
of the foot to the middle, when it curves towards  the
external edge, and joins the lesser saphena.  On  the 
316 Instances of peculiar arrangement of the Veins.

leg and foot it also sends off many branches, which
anastomose with each other, and with those of the
aforesaid vein.
   The femoral vein, after parting with the saphena,
soon sends off the vena profunda, and the  circum-
flexse also, when they do not arise from the  profun-
da.  These veins are generally larger than the arte-
ries to which  they correspond, and  their branches
are  more  numerous;  but they  observe the same
course.
   The great vein accompanies the artery down the
thigh and through the perforation in the  biceps;
but  it  changes  its relative position, so that it  is
placed behind  or on  the exterior side of the artery
at the lower part of the thigh.   It is very often be-
hind it in the ham, where, like the artery,  it takes
the name of popliteal.  In the  ham it sends off an-
other superficial vein, which  seems very analogous
to the basilar vein of the arm.  This is called

        The Lesser or External Saphena.

It proceeds from the  ham over the external  head  of
the gastrocnemius, and down the outside of the lre§,
sending off many branches in  its course.   It passes
behind the external ankle and near the exterior edge
of the upper surface of the foot, about the middle  of
which  it  inclines towards the great  saphena,  and
forms with it the anastomosis already  mentioned.
   The popliteal vein, after passing across the arti-
culation, ramifies  like the artery,  but  sends two
veins, which accompany each of the three arteries of
the leg.

   In a few instances  some of the larger veins have
been found to  be arranged in  a manner very differ-
ent from that which is commonly observed. 
Pulmonary Vessels.             317
   One case of this kind has already been mentioned
in the account of the liver,* where the Vena Porta-
rum terminated in the Vena Cava, below the liver,
without entering into it.
   Another very remarkable instance of peculiar ar-
rangement is to be seen in a preparation now in the
University of Pennsylvania,  in which  the  Inferior
Cava, instead of  opening into the  lower part of the
right auricle, passes  behind it,  in the tract of the
Vena Azygos, and opens into the Superior  Cava, in
the place  where the  Vena Azygos usually communi-
cates with  that  vessel,  receiving the  Intercostal
Veins in its course.
   In this preparation, the Hepatic Veins communicate
directly with the right auricle,  at its lower part; the
middle and left hepatic veins forming one trunk before
they enter, and the right vein passing in singly.f ■

   Of  the PULMONARY Arteries and Veins.

   Those portions of  the Pulmonary artery and veins
which are distinct from the lungs may be  described
very briefly.
   It has been already observed,! that the pulmonary
artery arises from  the left  and most anterior  part of
the  basis of the right ventricle, and proceeds  thence

  * See note to p. 132, of this volume.
  f The foregoing preparation was made by the present editor in 1814,
since  which two other anomalous cases have occurred to him.
  1819, Case 1st. The ascending cava passed into the thorax on the left
side of the spine, and getting as far as its upper part, was joined there by
the trunk of the internal jugular and subclavian of the left side.   It there
passed across the vessels of the arch of the aorta and joined with  the de-
scending cava.  The vessels of the liver entered the heart at the usual
place, in the lower part of the right auricle.
  1820, Case 2d. The trunk formed  by the junction of the internal jugu-
lar and subclavian of the left side instead of taking its usual course, passed
down vertrically, before the left branch of the pulmonary artery and be
fore the left auricle, then making a slight curve between this auricle and
the diaphragm joined with the ascending cava.—Ed.
  \ See page 59 of this volume*. 
 318            Pulmonary Vessels.

 obliquely backwards, inclining gradually to the left
 side for about eighteen or twenty lines when it divides
 into two branches, which pass to the two lungs. This
 course places it under the curve of the aorta : for that
 great vessel passes over the right branch  of the pul-
 monary artery, and the right side of the  main trunk
 of it, in such a manner that it proceeds  downwards
 between the two branches and behind the  angle form-
 ed by their bifurcation.  From this place of bifurcation
 a short ligament proceeds to the lower part of the curve
 of the aorta, which is almost in contact with it. This
 ligament was originally the canal that formed  the
 communication  between the  pulmonary  artery and
 the aorta of the foetus.   Each  of the great branches
 of the pulmonary artery takes a direction  backwards,
 and to its respective side.  It soon  joins  the corres-
 ponding branch of the trachea and the two pulmona-
 ry veins, being anterior to the branch of the trachea,
 and above the pulmonary veins.   It is also invested,
 in common with them, by that portion of the pleura
 which forms the mediastinum, and  thus enters into
 the composition of the root of the lungs.
   The Pulmonary Veins are  four  in number—two
 on each side. In conformity to the mode  of descrip-
tion which we have adopted, it may  be said that they
arise from the sides of the Left Auricle, and proceed
nearly in a transverse direction, two of them to each
lung; where they accompany the  branches  of  the
artery  and of the trachea, being invested by the
mediastinum  in  common with these  branches.   It
has been observed,  that they differ from veins  in
general, by  preserving  a diameter nearly similar  to
that of the arteries which they accompany. 
SYSTEM  OF  ANATOMY.

                 PART X.
                 OF THE NERVES.

  The  nerves  are those whitish cords which  pass
from the brain and spinal marrow to the various parts
of the body.
  A general account of their origin is contained  in
the description  of the basis of the  brain and of the
spinal marrow,* which may be considered as intro-
ductory to the present subject.
  The nerves, in general, appear to be bundles  or
fasciculi of small  cords, each of which is  composed
of a series of fibres that  are still smaller.   These
fibres consist of medullary matter,  which is  derived
from the brain and spinal marrow, and is enclosed in
a membranous sheath that appears to arise from the
pia mater.  The smaller the fibre  the more  delicate
is the membrane which invests it.
  As the nerves proceed from the  brain  and spinal
marrow, through the foramina of the cranium  and the
spine, they are  enclosed in a sheath formed  by the
dura mater; but when they arrive at the exterior
extremities of the foramina in those bones, this coat,
derived from the dura mater, appears to separate
into two lamina.    The  exterior  lamen combines
with the periosteum, and the interior continues to in-
* See volume I. page 333. 
320      General Structure of the Nerve.

vest the nerve, but seems to change immediately into
cellular substance; so that the exterior coat of the
nerves  may be regarded  as composed of  cellular
membrane, which  is continued  from the sheath de-
rived from the dura mater.
   It has been  supposed that the  membrane which
forms the sheaths for the medullary fibrils, of which
the  nerves are composed, is of  a peculiar nature;
but it appears  to be derived from the pia mater, in-
vesting the brain and the spinal  marrow.  It is  very
vascular.*
   The ramification of a nerve is simply the separa-
tion of some fibres from the general fasciculus.  The
branch commonly forms  an acute angle with the  main
trunk.
   The course of these branches from their origin to
their termination, is generally as straight as possible.
   When the nervous cords are examined in  an ani-
mal recently dead, there is an appearance  of white
lines arranged  in  a  transverse  or spiral direction.
The cause of this appearance is not well understood.
   In various parts  of the body net works are formed
by the combination of different nerves, or the branches
of nerves.  In those instances the branches  of one
nerve, unite with  those of  another,  and form  new
branches.   These  new  branches  again  divide,  and
their ramifications unite with other new ramifications
to form other new trunks. These  new trunks divide
again, and form new combinations in the same way.
   The trunks last  formed proceed to  the  different

  * Several authors have written professedly on the structure  of the
nerves, viz. Monro, in his  " Observations on the Structure and Functions
of the nervous  System."—Bichat, " Anatomie Generale."—Fontana,
" Treatise on the Poison of the Viper."—Reil, " Exercitationes Anato-
mic*."—Scarpa, " Annotationes  Academic*."—Prochaska,  " De Struc-
ture Nervorum."
  I regret, that it has not been in my power to procure Reil, Prochaska,
or Scarpa. 
              Plexuses.—Ganglions.          321

parts of the body, as other nerves do which arise im-
mediately from the brain.
  These combinations  are denominated Plexuses.
There are several of them in the cavities of the abdo-
men and thorax, formed by the ramifications of the
par vagum and the  sympathetic  nerves.   The  four
lower cervical and the first dorsal nerve form a very
remarkable plexus of this  kind, which  extends from
the side of the  neck to  the  axilla, and forms the
nerves of the arm.  The lumbar nerves form a similar
plexus, although not so complex, from which the  cru-
ral nerve arises.   The anterior nerves of the sacrum
also unite for the formation of the great  sciatic nerve.
  It appears  to be clearly ascertained, that the great
object of this peculiar  arrangement is  the combina-
tion of nervous  fibres  from many different sources,
in each  of the nerves, which  are distributed to any
organ.  Thus, the smaller nerves of the arm that are
distributed to the different parts, are not to  be re-
garded  simply as branches of any one of the five
nerves which are appropriated to the  upper extre-
mity, but as  composed of  fibres  which are derived
from each of  them.
   Many of  the nerves  are  enlarged in particular
places so as  to  form small circumscribed tumours,
which are denominated Ganglions.
   These Ganglions are  generally of  a reddish co-
lour.   By very dextrous  management, they can be
shown to consist of  a texture  of  fibres.  The larger
cords, which compose the  nerve, seem suddenly  to
be resolved into the small  fibres, of which they  con-
sist.  These  small fibres,  after proceeding separate-
ly a greater or lesser distance, according to the size
of the ganglion,  and changing their relative situa-
tion, are again combined in cords which recompose
the nerve.
   These fibres appear to be surrounded by a fine
   Vol. n.              41 
322         Structure of Ganglions.
cellular substance, which is vascular,  moist and soft.
It is asserted that,  in fat subjects, an oily substance,
resembling fat; and in  hydropic subjects, a serous
fluid has been found in this texture.
  Ganglions are often connected with but one nerve,
which  seems to enter at one extremity and go out at
the other.  But they frequently receive additional
branches from other nerves, and send off additional
branches to parts different from those to which their
principal nerves are directed.  When connected with
but one nerve,  they have  been called simple gang-
lions: when they  receive and  give off  additional
branches,  they are denominated compound gang-
lions.—It does not appear that there is any impor-
tant difference  in their structure in these cases.
  The simple ganglions occur in the nerves of the
spinal  marrow—the posterior fasciculus of the nerves
having always formed a ganglion  before it is joined
by  the anterior fasciculus.  The sympathetic nerve,
throughout its  whole extent, forms compound gang-
lions.
  The use of this particular  structure does  not ap-
pear to be perfectly known.   It seems,  however,
certain,  that the   different  fibres—(of  which the
nerves forming ganglions  are composed)—are blend-
ed  together and arranged in a manner different from
that in which they were arranged before  the nerve
entered  the ganglion.
   It ought to be observed, that  the combination  of
nervous fibrillae, so as to bring together those fibrils
which originally belonged to different cords, seems
 to  have  been kept in view throughout the whole ar-
 rangement of  the  nervous system.   It is not only in
 the plexus and the ganglion that this appears, but
 also in some of the larger nerves; for in them, the
 fibres which form the cords that compose the nerve,
 instead of running parallel to each  other,  along the 
             Reproduction of Nerves,          323

 whole extent of the nerve, form a species of plexus in
 their course; separating from the  fibres  with which
 they were originally combined, and uniting with the
 fibres  of other cords ;  as in other cases of plexus.*
   There have been doubts respecting the possibility
 of a reproduction of the substance of the nerves when
 it has  been destroyed; but it appears  to have been
 clearly proved by the experiments of Mr. Haighton,
 that a  reproduction does really take place.f
   Nine pair of nerves proceed from the brain through
 the foramina of the cranium.  They are called Nerves
 of the Brain, or Cerebral Nerves.  One pair passes
 off between the cranium and the spine, which is call-
 ed Sub-Occipital.   Twenty-nine or thirty pair pass
 through the foramina of the  spine :  they are deno-
 minated  Cervical,  Dorsal,  Lumbar, and Sacral,
 from the bones  with which they are respectively
 connected.  There are seven pair of Cervical nerves,
 twelve Dorsal, five Lumbar, and five or six Sacral—
 amounting,  with  the  nerves of the  brain, to  thirty-
 nine or forty pair.
         NERVES OF  THE BRAIN.

   The nerves which  go off from the brain and me-
 dulla oblongata  are  named  numerically,  according
 to the  order in  which they occur; beginning with
 the anterior.  They also have  other  names, which
 generally are expressive of the functions  of the dif-
 ferent parts to which they are distributed.
   Those which go to the nose are anterior to all the
 others, and are therefore denominated
   THE FIRST PAIR, OR THE OLFACTORY NERVES.

 They arise by three delicate white fibres from the

  * See Monro's Observations on the Structure and Functions of the Ner-
vous System.  Plate xviii.
  t See London Philosophical Transactions* for 1795, Part I.   . 
324             Olfactory Nerves.
under and posterior part of the anterior lobes of the
brain, being derived from the Corpora Striata. They
proceed forward to the  depression on the cribriform
plate of the ethmoid bone, on each side of the crista
gajli.   The upper surface  occupies a small sulcus
formed  by the  convolutions of  the lower  surface of
the brain, and,  therefore, has a longitudinal ridge on
it.  The lower surface is flat.  Their texture is like
that of the medullary  part of the brain.
  On  each side of the  crista galli each of them forms
a pulpy enlargement of  a brownish colour, which is
called the bulb, and has been considered as a gang-
lion.
  From this bulb many fine and delicate cords go off,
which proceed through the dura mater and the fora-
mina  of the  cribriform plate to the  Schneiderian
membrane.—These ramifications  of the  olfactory
nerve seem to receive a coat from the dura mater,
as they  are much more  firm after  they have passed
through it.  They  appear to be arranged in two rows
as they  proceed from the ethmoid bone—one running
near to  the septum, and the other to  the opposite
surface of the ethmoid bone.*

    THE SECOND PAIR, OR THE OPTIC  NERNES,

Originate  from  the  Thalami Nervorum Opticorum,
and appear on the external and lower surface of the
brain, on  each side of the sella turcica.
   Each of them seems like a cord of medullary mat-
ter, enclosed in a coat derived from the pia mater, and
has not the fasciculated appearance of the other nerves.
The medullary matter, however, appears to be divided
by processes that pass through it, which are derived
from  the coat of the nerve.
* See Vol. II. v 6. 
        Second and Third Pair of Nerves.     325

  They proceed  obliquely forward, and inward, on
each  side of the sella turcica, in contact with the
brownish cineritious substance, in which the infundi-
bulum and the corpora albicantia of Willis are situa-
ted.*  Anterior to this substance they come in con-
tact with each other, and again separate, in such a
way, that it is an undecided  question whether they
decussate each other, or whether each  forms an an-
gle, and is in contact with the other at the angle.
  From this place of contact, each  nerve proceeds
to its respective foramen opticum, where  it receives
a coat from the dura mater, which extends with it to
the eye, as has been described in the account of that
organ.
           THE THIRD PAIR OF NERVES

Are sometimes called Motores Oculorum, in conse-
quence of their distribution to several muscles of the
eye.  They arise at the  inside of the crura cerebri,
and make their appearance on the basis of the brain,
at the anterior part of the pons Varolii.
  They originate  by numerous threads, which  soon
unite so as to form a cord, which passes through the
dura  mater, on each side of the posterior clinoid  pro-
cess, and continues through the cavernous sinus, and
the foramen lacerum, to the orbit of the eye.
  Before this nerve enters the orbit it generally di-
vides into two branches, which are situated one above
the other.   The  Uppermost  Branch is spent princi-
pally upon the rectus superior muscle of the eye, but
sends a twig to the levator palpebral.  The Inferior
Branch  is distributed to two of the recti  muscles,
viz. the  internus  and the inferior, and also to the
inferior oblique.   It likewise sends a twig to a small
ganglion in the orbit, called the Lenticular or  Oph-
* See Vol. I. page 323 
 326     Fourth and Fifth Pair of Nerves.

 thalmic Ganglion,* from which  proceed the  fine
 nervous fibres that perforate the sclerotica coat.-jr

           THE FOURTH PAIR OF NERVES

 Are called the Pathetic, in  consequence of the ex-
 pression of the countenance  produced by the action
 of the muscle on which they are spent.  They arise
 from the side of the valve of the brain, below and be-
 hind the Tubercula Quadrigemina,$ and are so small
 that they appear like sewing thread.  They proceed
 round the crura of the cerebrum, and appear on the
 surface between  the pons Varolii   and the middle
 lobes of the brain.  They proceed along the edge of
 the  tentorium which  they  perforate, and  passing
 through the upper part of the cavernous sinus, enter
 the orbit by the  foramina lacera.   They are exclu-
 sively appropriated to the Superior Oblique or Troch-
 lears muscle.
            THE  FIFTH PAIR OF NERVES

 Are called Trigemina, because each nerve divides
 into three great branches.
  These nerves arise from the crura of the  cerebel-
 lum where they unite to the pons Varolii, by distinct
 fibres, which  are  connected so as  to  form a cord or
 nerve, that is larger than any other nerve of  the
 brain.  In many subjects  this cord seems partially
 divided into  two portions, the anterior of which  is
 much smaller than the posterior, and  appears softer
at its origin.
  It  passes  into  a short canal formed by the dura
 mater, near the anterior extremity of the petrous por-

  * This ganglion, which is considered as the smallest in the body lies on
the outside of the optic nerve, near its entrance into the orbit, and is ge-
 nerally surrounded by soft adipose matter.
  t See Vol I. page 366.
  i See Vol. I. page-335. 
         First Branch of the Fifth Pair.     327

tion of the temporal  bone, at a small distance below
the edge of the tentorium.   It is perfectly loose and
free from adhesion to the surface of this canal; but
it soon passes out of it under the dura mater, and then
adheres to that membrane.   After leaving the canal
it expands  like a fan, but still consists of fine fibres
which have some firmness.   It is said that there are
seventy or eighty of these fibres in the expansion, but
they appear to be more numerous.   Round the cir-
cumference of the expansion is a substance of a brown-
ish colour,  into which the fibres enter.   This is the
Semilunar Ganglion, or the Ganglion of Gasser,
and from it the three nerves go off.
  These nerves pass off from the convex side of the
Ganglion, and  are denominated the Ophthalmic, the
Superior Maxillary, and the Inferior Maxillary.

              The Ophthalmic Nerve

Passes into the orbit of the eye through the foramen
lacerum: it there divides into several branches, which
are called,  from their distribution, the Frontal or Su-
pra Orbitar, the Nasal, and the Lachrymal.
  The  Frontal or Supra Orbitar  branch proceeds
forward^in the upper  part of the orbit, exterioi  to
the membrane which lines it,  and divides into two
ramifications.   One of these is small, and  passes out
of the orbit near the pulley  of the superior oblique,
to be spent upon the orbicularis muscle and the con-
tiguous parts.
  The other ramification passes  through the  Supra
Orbitary Foramen, or through the notch, which is in
the place of that foramen, and divides into a number
of twigs, some of which pass transversely towards
the side of the head,  and communicate with twigs
from the portio dura. Most  of the others extend up-
wards on the head.  Some are distributed  to the an- 
 328    Second Branch of the Fifth Pair.

 terior part of the occipito-frontalis  muscle, and  the
 integuments of the forehead;  others are spent upon
 the upper portion of the scalp. Some of the extreme
 parts of these ramifications also communicate with the
 portio dura.
   The  Nasal  Branch  proceeds  obliquely forward
 towards the inner side of the orbit,  and sends a twig
 in its course to  the lenticular ganglion.  It also sends
 off some small twigs, to join the ciliary nerves which
 go from the ganglion.  On the inside of the orbit a
 branch leaves it, which  proceeds  through the Fora-
 men Orbitare Internum  Anterius to the cavity of
 the cranium, and  passes  a small  distance upon  the
 cribriform plate of the ethmoid bone, under the dura
 mater, to a fissure in the said  plate near the  crista
 galli, through which  it  proceeds  into the cavity of
 the nose.   Here it divides into twigs, some of which
 pass on the septum  near  its  anterior edge, and ter-
 minate on the integuments at the end of the nose,
 while others pass down  on  the  inferior  turbinated
 bone.
   After parting with the ramification to the nose, the
 remainder of the nasal branch continues  to  the  in-
 ternal canthus  of the  eye, and sends twigs to  the
lachrymal sac,  the caruncula lachrymalis, the eye-
lids, and the exterior surface of the upper part of the
nose.
   The Lachrymal  Branch  proceeds obliquely for-
ward and outwards,  towards  the lachrymal  gland.
 In its course it  sends off a twig which passes through
 the spheno maxillary fissure, and  communicates with
a  twig of the  upper maxillary  nerve, and one  or
 more twigs that pass, to foramina in  the malar bone.
The main branch passes to the lachrymal gland, and
 some twigs continue  beyond  it  to the contiguous
 parts. 
         Second Branch of the Fifth Pair.     329

          The Superior Maxillary Nerve.

   The second branch of the fifth pair is  examined
with great difficulty on account of its peculiar situa-
tion.   It proceeds from the semilunar ganglion, and
passes through the foramen rotundum of  the sphe-
noid bone into the upper part of the zygomatic fossa.
In this situation it sends a twig to  the orbit by the
spheno  maxillary fissure, and a  branch, called the
Infra Orbitar, which appears like  the main nerve,
as it preserves a similar direction, to the infra orbitar
canal.   At the same place it  sends  downwards two
branches which unite together almost immediately af-
ter their origin, and, as soon as they have united, en-
large into a ganglion.*  This ganglion is  called the
Spheno-Palatine.  It is rather of a triangular figure,
and lies  very near  the spheno-palatine foramen.   It
gives off a posterior branch, which passes through the
pterygoid foramen to the cavity of the cranium: some
branches which proceed through the spheno-palatine
foramen  to the nose, and are called the  Spheno-Pala-
tine or Lateral Nasal Nerves: and an inferior branch
that proceeds through the  posterior palatine  canal,
and is called the Palatine Nerve.
  The smajl branch,  which was first  mentioned,  as
going to the orbit  by the  spheno maxillary fissure,
divides into two  ramifications.  One of them unites
with a twig of the lachrymal branch above mention-
ed, and passes out of the orbit, through a foramen  in
the malar bone, to the face; where it is distributed.
The other passes also through a foramen of the ma-
lar bone, into the temporal fossa, and, after uniting
with twigs from the Inferior Maxillary Aerve, pro-
ceeds backwards and  perforates  the aponeurosis  of

  * Sometimes a single branch passes  downwards instead of two; but it
forms a ganglion in the same place.
   Vol. it,              42 
 330        Superior Maxillary Nerve.

 the temporal muscle, to terminate on the integuments
 of the temporal region.
   Before the Infra Orbitar branch enters the canal
 of that name, it sends off two twigs, called Posterior
 Dental Nerves, wThich pass downwards on the tube-
 rosity of the upper  maxillary bone, and enter into
 small canals in that  bone,  that are situated behind
 the Antrum Maxillare.   They subdivide into fine
 twigs that proceed forward to the alveoli of three or
 four of the last  molar teeth; and penetrate each of
 the roots  by a cavity at its extremity.   Twigs also
 proceed from these nerves to the posterior part of the
 gums and buccinator muscle.
  After the posterior dental nerves have left it, the
 Infra Orbitar nerve proceeds forwards in the canal of
 that name; and near the extremity of it, gives off the
anterior dental nerve, which accompanies it for some
distance, and then proceeds downwards in a  canal in
the bone anterior to the antrum maxillare.  In its
course  this nerve divides into many fibres, which pass
to the  roots of the incisor, canine,  and small molar
teeth, each in its proper canal. These dental branches
sometimes pass in the antrum maxillare between the
lining membrane and the bones.   The Infra  Orbitar
nerve passes out of the foramen  upon the cheek, and
divides into several branches of considerable size,
which are distributed on the face from the side of the
nose  to the back of the cheek, and also  upon the un-
der eye-lid and the upper lip.
  The Pterygoid Nerve, or posterior branch, passes
backwards, from the ganglion to a canal in the  base
of the  pterygoid process of the Os  Sphenoides, and
proceeds through it.   After leaving  this canal, it
 passt*  through a substance almost  as  firm as carti-
 lage, which closes the anterior  foramen lacerum, at
 the basis of the cranium;  and  divides  into  two
 branches.  The smallest of them, called the Vidian 
            Superior Maxillary Nerve.         331

Nerve, proceeds with a small artery to the small fo-
ramen, or Hiatus Fallopii, on the anterior side of the
petrous portion of the temporal  bone, and continues,
through a small canal, to join the Portio Dura of the
seventh pair in the larger canal, called the Aqueduct
of Fallopius, at the first turn in that  canal.*  The
other branch of  the pterygoid nerve proceeds to the
Foramen  Caroticum, and passes through it, with a
twig of the sixth pair, to join the first cervical gan-
glion of the Intercostal Nerve.
  The Spheno-Palatine, or Lateral Nasal Nerves,
consist  of   several branches which pass  from  the
spheno-palatine ganglion through the  Spheno-pala-
tine foramen into the nose.   Some of  them  are  dis-
tributed to that part of the pituitary membrane, which
is above the upper meatus, and others to the part which
is immediately below it.  Some of the branches which
thus enter the nose  are spread upon the septum; one
among  them extends upon it,  downwards and  for-
wards  to the anterior part of the palatine process of
the upper  maxillary bone, where it enters into the
foramen incisivum, and terminates in a  papilla in the
roof of the mouth.-j*
  The Palatine Branch proceeds through the canal
formed by the upper maxillary  and palate  bones, to
the roof of the mouth and the soft palate.   Soon af-
ter its origin, it sends  off a twig which  proceeds
down a small canal  that is  behind it.  It also sends
off, as it proceeds downwards, several  twigs  to  that
part of the membrane of the nose which covers the

  * The late Mr. John Hunter believed that this nerve parts from the
portio dura at the lower end of the aqueduct, and is the chorda tym-
pani.
  t The  curious distribution of this nerve appears to have been known to
the late John Hunter, and also to Cotunnius; but it is minutely described by
Scarpa, and is delineated by Soemmering in his plate of the nose—See
" Observations  on certain parts of the Animal Economy," by J. Hunter,
page 219, and also Scarpa " De Organo Olfactus." In this last are some
interesting observations relative to the ducts of Steno. 
332     Third Branch of the Fifth Pair.

inferior turbinated bone.   When it arrives at the
roof of the mouth, it divides into several branches
which run forwards, and are distributed to the mem-
brane which lines  the roof of the mouth.   Some of
its branches pass to the soft palate, the uvula, and
the tonsils; small filaments pass into the back part of
the upper  jaw.

The inferior Maxillary Nerve, or the Third Branch
                of the Fifth Pair,

Passes through the foramen ovale into the zygomatic
fossa, and  divides  into  two branches, one of which
sends ramifications  to many of  the  contiguous mus-
cles, as the Temporal, the Masseter, the Buccina-
tor, the Pterygoid; and also to  the anterior part of
the ear and the side of the head.  The other branch
passes between the pterygoid  muscles,  and divides
into two ramifications, one of which proceeds to the
tongue, and  is  called the Lingual or Gustatory,
while the  other passes into the canal of the lowep
jaw.
   The Lingual Nerve proceeds between the ptery-
goid muscles,  and  in  its  course is joined  by  the
chorda tympani.   It continues forward  between the
maxillary  gland and the  lining  membrane of  the
mouth; and passes  near the excretory duct of that
gland, above the mylo-hyoideus and the sublingual
gland, to  the  under side of the  tongue, near  the
point: it  then  divides into a  number of branches
which enter into that body between the genio-hyoi-
deus  and  lingualis muscles.   This nerve has been
supposed to be particularly concerned in the  function
of taste, because  many of its branches continue  to
the upper surface  of the tongue, especially near  the
point.  In its  course it has a communication with
the »inth  pair of  nerves,  and it sends twigs to the 
The Sixth Pair of Nerves.        333
membrane of the mouth and gums, and the contiguous
parts.
  After parting with the lingual nerve, the inferior
maxillary continues to the upper and posterior orifice
of the canal in the lower jaw.   Before it enters this
canal it  sends a branch  to the sub-maxillary gland,
and to the muscles under the jaw.  It then enters the
canal, attended by blood vessels, and proceeds along
it to the anterior maxillary foramen, on the side of the
chin, through which it passes out.   In  this course it
sends twigs to the sockets of the teeth, and generally
supplies all the large and one of the small grinders.
Before it leaves the jaw it sends a branch forwards,
which supplies  the remaining teeth on the side  to
which it belongs.  After passing out, through the an-
terior foramen, it is spent upon the muscles and inte-
guments of the front of the cheek, the chin, and the
under lip.

           THE SIXTH PAIR OF NERVES

Are called Motores Externi.  They arise  from the
commencement of the  medulla oblongata, and pro-
ceed forward under the pons Varolii.  They proceed
through the dura  mater on the  inside of the fifth pair,
and  appear to pass  through  the cavernous sinuses,
but are enclosed  in sheaths of  cellular membrane
while they are in those sinuses.  When in this situa-
tion they are near the carotid arteries, and each nerve
sends off one or more very fine  twigs, which being
joined by  a twig from  the pterygoid branch of the
fifth pair, accompany the carotid artery through the
carotid canal, and then unite themselves to the upper
extremity of the  upper cervical ganglion of the in-
tercostal nerve.
   The sixth pair afterwards pass into the orbit of the
eye, each through the foramen lacerum of its respective 
334     Composition of the Seventh Pair.

side, and is spent upon the Rectus Externus or Ab-
ductor muscle of the eye.

          THE SEVENTH PAIR OF NERVES

Comprises two distinct cords which have very differ-
ent destinations; and have, therefore, been considered
as different  nerves, by several anatomists.  One of
these cords is appropriated to the interior of the ear,
and is  the proper Auditory Nerve.   The other is
principally spent upon the face, and, therefore,  has
been called the Facial.  They have,  however, more
frequently been denominated the Seventh Pair, and
distinguished from each other,  in consequence of a
great difference in their texture, by the appellations
of Portio Dura and  Portio  Mollis.
   These two  cords  pass  off nearly in contact with
each other, from the side of the upper part  of the
Medulla Oblongata, where it is in contact with the
pons Varolii; but the Portio Mollis can be traced to
the fourth ventricle, while the Pwtio Dura is seen to
rise from the union of the  pons Varolii with the me-
dulla oblongata and the crura Cerebelli.  The  Portio
Dura, at its origin, is on the inside of the  Portio
Mollis.  Between these cords are one or more small
fibres,  called Portio Media, which seem to originate
very near them,  and finally unite with the  Portio
Dura.
   Each of the seventh pair  of nerves, thus compo-
sed,  proceeds from its origin, to the Meatus Audito-
rius Internus of the temporal bone ;  and the Portio
Mollis divides into fasciculi, which  proceed to the
different parts of  the organ of hearing, in the man-
ner described in the account of the ear.*
   The Portio Dura enters  an orifice at the upper
and anterior part of the end or bottom of the Meatus
* See Vol. I. p. ??6, 
        Chorda  Tympani.—Pes Anserinus.   335

Auditorius Internus.  This orifice is the commence-
ment of a canal,  which has been called the Aqueduct
ofFallopius, and proceeds from the Meatus Audito-
rius Internus to the external foramen,  between the
mastoid and styloid processes at the basis of the cra-
nium.   This canal first curves backwards and out-
wards, near to the upper surface of the petrous bone,
then forms  an  acute angle, and  proceeds,  (back-
wards and downwards,) to the stylo-mastoid foramen,
passing very near the cavity of the tympanum in its
course.
  The Portio Dura, as it passes into the canal from
the meatus internus, seems to receive an investment
from the dura mater.  It fills up the canal, but does not
appear to be compressed.  Near the angle it is joined
by the twig of the vidian nerve, which proceeds from
the pterygoid branch of the fifth pair, and enters the
petrous bone by the small foramen  innominatum  on
its anterior surface.  In its course through the canal
it sends  off some very  small twigs  to  the muscles
and appurtenances of the small bones of the ear, and
to the mastoid cells; and,  when it has arrived almost
at the end of the canal, it sends off, in a retrograde
direction, a small branch which proceeds into the ca-
vity of the tympanum, (entering it by a foramen near
the base of the pyramid,) and crosses the upper part
of it, near the membrana tympani, between the long
processes of the Malleus  and Incus.  This twig  is
theCorda Tympani ; it proceeds from  the cavity, by
a fissure on the  outside of the  Eustachian tube,  to
join the lingual branch of the fifth pair, as has been
already mentioned.*
  The Portio Dura, after passing out of the Fora-

  * The late John Hunter believed  that the chorda tympani is merely a
continuation of the twig of the pterygoid branch which joins the portio
dura above ,-^See Observations on certain parts of the Animal Econornv,
page 220. 
 336  Composition of the Eighth Pair of Nerves.

 men Stylo-Mastoideum, is situated behind and with-
 in the parotid gland.   Here  it gives small twigs  to
 the back of the ear and head, and to the digastric
 and stylo-hyoideus muscles.   It perforates the gland
 after sending filaments to it,  and then divides  into
 branches which are arranged in such a manner that
 they  constitute what has been called the  Pes  Anse-
 rinus.
   To describe  the various branches in this  expan-
 sion would be more laborious than useful.  Some of
 them are spread upon the temple and the upper part
 of the side of the head, and unite with the supra-or-
 bitar branches of the ophthalmic nerve.  Some  pass
 above and below the eye,  and are distributed to the
 orbicularis muscle,  and communicate with  nervous
 twigs that pass through foramina in the malar bone,
 &c.   Some large branches pass transversely.   They
 cross  the masseter muscle, and divide into  ramifica-
 tions which are  spent upon the cheek and the side of
 the nose and lips,  and  communicate with  the small
 branches of the superior maxillary nerve.
  A  large  number of  branches pass  downwards.
 Many of them  incline forwards,  and  are  spent on
 the soft parts about the under jaw; while others pro-
 ceed  below the jaw to the superficial muscles  and
 integuments of the upper part of the neck, communi-
 cating with the branches of the contiguous nerves.*

          THE  EIGHTH PAIR OF NERVES

 Are very frequently denominated the Par Vagumf
on account of their very extensive distribution.

 • * A most minute and laboured description of the nerves of the face was
published by the celebrated Meckel, m the seventh volume of Memoirs
of the Royal Academy of Sciences of Berlin, for the year 1751, accompa-
 nied with a plate, exhibiting the side of the head, of three times the natu-
 ral size.  This  is republished in the  Collection  Academiqtte • Partie
 Etrang&e.—Tom. viii.                          * 
  Composition of the Eighth Pair of Nerves.  337

  They arise from those portions of the medulla ob-
longata which are denominated the Corpora Olivaria.
Each nerve consists of a cord, which is anterior, and
called the Glosso Pharyngeal; and of a considerable
number of small filaments, which  arise separately,
but unite and form another cord, the proper Par Va-
gum.  Associated with these is a third cord, called
the Spinal, or Accessory Nerve of Willis, which ori-
ginates in the great canal of the spine, and, passing
up into the cavity of  the cranium, goes out of it with
these nerves through the foramen lacerum.
  The two first mentioned nerves proceed from their
origin to  the  posterior foramen lacerum, and  pass
through it with  the  Internal Jugular vein,—being
separated from the vein by a small process  of bone.
They are also separated from each other by a small
process of the dura mater.   In the foramen they are
very close to each other  ; but soon after they have
passed through it, they separate and proceed towards
their different destinations.
  The  Glosso-Pharyngeal  proceeds towards  the
tongue,  between the  stylo-pharyngeus and the stylo-
glossus muscles, following  the course of the last men-
tioned muscle to the posterior part of the tongue.  At
the commencement of its course it receives a twig from
the Portio Dura .and one  also from the Par Vagum.
It soon gives off a branch which passes down on the
inside of the common carotid to the lower part of the
neck, where it joins  some twigs of the intercostal to
form the  cardiac nerves.   Afterwards it sends off
several twigs to the muscles of the pharynx and its
internal membrane, and also some twigs which unite
with others from the upper cervical ganglion of the
Sympathetic, and form a network that lies over the
anterior branches of the external carotid. The Glosso-
pharyngeal finally enters the tongue, at the termina-
  Vol.  n.              43 
338  Glosso-Pharyngeal Nerve.—Par Vagum,

tion  of the  hyo-glossus muscle; and after sending
tranches to the lingualis, and the various muscles in-
serted into the tongue, terminates in small ramifica-
tions that are spent upon  the sides and middle of the
root of the tongue, and upon the large papillae.
                THE PAR VAGUM

Are slightly enlarged after passing through the fora-
men lacerum.   As they descend, they adhere to the
superior  ganglion of the intercostal, and  also to the
ninth pair.  They proceed behind and on the outside
of the carotid, and are contained in the same sheath of
cellular membrane which encloses that artery and the
internal jugular vein.  Each of these  nerves,  soon
after it leaves the cranium, gives a twig to the glosso-
pharyngeal ; that soon after it sends off a branch called
the Pharyngeal, which unites to one from the acces-
sory  nerve, and to one or more from the glosso-pha-
ryngeal,  and proceeds to the middle constrictor of
the pharynx, when it expands into ramifications that
form a plexus from which proceed a number of small
twigs that go to the larynx, and some that pass down
on the common carotid artery.
   It then sends off,  downward and forward, the Su-
perior Laryngeal nerve, which continues in that di-
rection behind  the carotid artery,  and divides into
an external and internal branch.
   The Internal Branch, which is the  largest,  pro-
ceeds between  the os  hyoides  and the thyroid carti-
lage ;  and divides into numerous ramifications which
are distributed to the  arytenoid  muscles and to the
membrane which lines- the larynx and covers the epi-
glottis.  It is said, that fine twigs can be traced into
the foramina, which  are to be seen in the cartilage
of the epiglottis;—some ramifications can be traced
to the  pharynx;—others  communicate  with  the
branches of the recurrent nerve. 
Superior Laryngeal Branchof the Par lagim. 339

  The External Branch sends twigs to the pharynx,
to the lower and inner part of the larynx, and to the
thyroid gland.
  In its course  downwards,  the  great  nerve some-
times sends off a twig, which unites with one from
the ninth pair that passes to the  sterno-hyoidei and
sterno-thyroidei muscles.
  It uniformly sends off one or  more twigs,  which
pass into  the thorax  and  combine   with  small
branches from the sympathetic or intercostal nerve,
to form the Cardiac plexus, which sends  nerves to
the heart.
  After entering  the thorax, the right trunk  of the
Par Vagum passes before the subclavian artery; and
the left trunk before the arch of the aorta ; and im-
mediately after passing  these arteries,  each  of the
nerves divides into an interior and posterior branch.
The anterior is the continuation of the Par Vagum;
the posterior is a  nerve of the Larynx;  which, from
its retrograde course, is called the Becurrent Nerve.
  On the left side the Recurrent Nerve winds back-
wards  round the  aorta,  and on the right side round
the subclavian artery, and proceeds upwards, deeply
seated, on the side  of the trachea,  to  the Larynx.
Soon after its origin it sends filaments to a ganglion
of the sympathetic, to the cardiac plexus, and to a
pulmonary plexus  soon to be  mentioned.   In its
course upwards it sends twigs to the trachea and the
oesophagus.  It proceeds  behind the thyroid gland,
and sends twigs to that organ.  At the lower part of
the larynx it sends off a branch  which communicates
with branches of  the superior laryngeal nerve.  It
also divides into branches which are spread upon the
posterior crico-arytenoid, and the arytenoid muscles;
and also upon the lateral crico-arytenoid and the
thyro-arytenoid muscles, as well as upon  the mem- 
340   Recurrent Branch of the Par  Vagum.

brane which lines the back part of the larynx and the
contiguous surface of the pharynx.
  There is a difference in the arrangement of the re-
currents on the different sides in consequence of one
winding round the aorta, while the other winds round
the subclavian artery.
  After sending off the recurrents, each trunk of the
par vagum proceeds behind the  ramifications of the
trachea; but previously detaches some small branches,
which are joined by twigs from  the  intercostal and
from the recurrent, and form a plexus upon the an-
terior part of  the vessels going to  the lungs.   This
Anterior plexus, after sending  off-some minute
branches to  the cardiac  nerves and the pericardium,
transmits its branches with  the bronchia  and the
blood vessels,  into the substance  of the lungs.
   Some of the branches which proceed from the par
vagum, pass down on  the  posterior part of the tra-
chea, and enter into the membrane which  forms it,
and the mucous glands which are upon it; and some
pass to the cesophagus.
   When the  par vagum is behind the great vessels
of the lungs, a number of branches go off transverse-
ly, and are  also joined by some fibres from the sym-
pathetic.  These form the Posterior pulmonary
plexus; the  ramifications  from which proceed into
the substance of the lungs, and are principally spent
upon the ramifications of the bronchia.   It has been
 said,* that the small  twigs into which they divide,
 very generally penetrate into the small ramifications
 of the bronchia,  and  are spent  upon their internal
 membrane.
   Soon after sending off the nerves 0L#the pulmona-
 ry plexus, the  Par  Vagum  proceed  downwards
  * See Buisson,  in the continuation of the  Descriptive Anatomy of
 Bichat. 
   Different Functions of the Laryngeal, fye. 341

upon the cesophagus;  the left nerve being situated
anteriorly, and the right posteriorly.  Each of these
nerves forms a plexus so as  nearly to surround  the
cesophagus, as they descend on it; but the net-work
is thickest on the posterior side.   They pass through
the diaphragm with the cesophagus, and unite again
so as to form considerable trunks.
  The Anterior, which is the smallest, proceeds along
the lesser curvature of the stomach to the pylorus.
Some of  its  fibres are spread upon the anterior side
of  the stomach and the  lesser omentum.   Others of
them extend to the left hepatic,  and also to the solar
plexus.
  The Posterior trunk  sends branches to  surround
the cardiac orifice of the  stomach.   Many branches
are spread upon the under side of the great curvature
of the stomach.   Some of them pass in the course of
the coronary artery to the cceliac, and unite to the
hepatic and  splenic plexuses; and one trunk, which
is thick,  although short, proceeds to the solar  plexus.
         The Accessory Nerve of  Willis,

Which has  been  mentioned as  associated  with the
eighth pair  of nerves, within the cranium, has a very
peculiar origin.
   It arises  by small filaments, which come off from
the spinal marrow, between the anterior and posteri-
or fasciculi of the cervical nerves, and proceeds  up-
wards to the great occipital foramen, between these
fasciculi.  It commences sometimes at the sixth or
seventh  cervical vertebra, and sometimes about the
fourth.  It  enters the cavity of the cranium through
the foramen^magnum, and proceeds upwards and out-
wards, so as to join the eighth pair of nerves at some
distance  from its origin, and in this course it receives
filaments from the medula oblongata.
   After approaching very near to the eighth pair of 
342         Ninth Pair of Nerves.
nerves, it accompanies it to the foramen lacerum, and
passes out in its own separate sheath.   It then leaves
the eighth pair and descends  towards the shoulder,
proceeding through the sterno-mastoid muscle.  Soon
after it emerges from the  cranium, it sends a ramifi-
cation to the pharyngeal branch of the Par Vagum
and another to the par vagum itself.   After passing
through the upper and back part of the sterno-mastoid
muscle, it terminates in the  trapezius.  It adheres
to the  ninth  pair of nerves  as  it  passes by it, and
sends a twig to  the  sub-occipital and  some of the
cervical nerves.   It also  gives  ramifications to the
sterno-mastoid muscle as it passes through it.
    It has already been stated that the Laryngeal and Re-
      current Nerves appear to answer different purposes in
      their distribution to  the Larynx.—When both of  the
      recurrent nerves are divided in  a living animal,  the
      voice seems to be  lost.  When  the laryngeal nerves
      only are divided,  the strength of the voice remains,
      but it is flatter.  The recurrent nerves, therefore, seem
      essential to the formation of the voice.   The laryngeal
      nerves are necessary to its modulation.
        The history of the investigation of this subject is
          contained in Mr.  Haighton's paper in the third
          volume of  Memoirs of the Medical Society of
         London.
           THE NINTH PAIR OF NERVES.
  Each of these nerves arises from the groove in the
medulla oblongata, between the corpora pyramidalia
and the corpora olivaria.  Three or four fasciculi, of
distinct filaments, unite to form it.   Thus composed,
it proceeds to the anterior condyloid  foramen of the
occipital bone, and  passes through the  dura mater.
It seems firmly united, by the cellular membrane, to
the eighth pair, and to the first ganglion of the  sym-
pathetic, soon after it passes from the occipital bone.
It is either connected to the sub-occipital nerve by a
small ramification, or it joins a branch which  pro- 
        Ninth and Tenth Pair of Nerves.    343

ceeds from  the  sub-occipital  to the  cervical, and
bends round the transverse process of the atlas.  It
passes between the internal carotid artery and the
internal jugular vein, and crosses the external caro-
tid  at the  origin of the occipital artery.   At this
place it  generally sends downwards a large branch
which is called the Descendens Noni.   Passing for-
wards, it is  on the outside of the posterior  portion
of the digastric muscle,  and inclines downwards; but
near the tendon of the muscle it turns upwards, and
proceeds on the inside of the mylo-hyoideus, where
it divides into ramifications, which, at the anterior
edge of the hyo-glossus muscle, begin to enter into
the substance of the tongue, between the genio-glos-
sus  and  the  lingualis muscles.
  Some  of  the branches of this nerve unite  with
those of the lingual branch of the fifth  pair.   Others
are  distributed to almost all  the muscles connected
with the tongue.
  The branch called descendens noni passes down
in the course of  the common carotid artery, and
sends branches in its progress to the upper  portions
of the coraco-hyoidei and sterno-thyroidei muscles;
it unites with ramifications of various sizes from the
first, second and third cervical  nerves, which form a
bow under  the sterno-mastoid muscle, from which
ramifications go to the lower portions  of the sterno-
hyoidei and thyroidei  muscles and of the  coraco-
hyoidei.

       OF THE CER VICAL NER VES.

  The tenth or last pair of the head, commonly call-
ed  the  Sub-occipital,  may be arranged with these
nerves, because they arise, like them, from the me-
dulla spinalis, and are  distributed to the muscles  on
the neck. 
344  Sub-Occipital or,  Tenth pair of Nerves.

            The sub-occipital Nerves

Arise on each side of the spinal marrow, nearly op-
posite to the interval between  the  great foramen of
the os occipitis and the atlas.
  Each of these nerves  consists of an anterior and
posterior fasciculus,  or bundle of fibres, which pass
outwards immediately under the vertebral arteries,
and form a ganglion,  from which proceeds an ante-
rior and a posterior branch.
  The anterior branch is united to  the second cervi-
cal  nerve below, and to the ninth nerve, or the hy-
po-glossal,  above.   It also sends filaments to the up-
per ganglion of the great sympathetic nerve.
  The posterior branch is spent upon the Recti, the
Obliqui, and some other muscles of the head.
  The proper Cervical Nerves consist of seven pair;
of which the first six go off between the vertebrae of
the neck,  and  the seventh between  the last of the
neck and the first of the back.

            The first cervical Nerve
Passes  out between the atlas and the  Vertebra Den-
tata.   It  originates from two fasciculi, which are
connected to each other at a ganglion, and then sepa-
rate into an anterior and  a posterior branch.*
  The anterior branch is connected by filaments with
the accessory nerve, with the ninth pair of the head,
and with the upper ganglion of the sympathetic.  It
is also connected with the second cervical nerve; and
sends some branches to the muscles on  the anterior
part of  the  spine.
  The  posterior branch, after communicating  with
the posterior branches of  the sub-occipital and the

  * This arrangement is common to the nerves of the spine.  The ganglion
is formed by the posterior fasciculus. 
           Cervical and Phrenic Nerves.       345

second nerves of the neck, perforates the complexus
muscle, and ascending upon the back of the head, is
distributed with the occipital artery.

           THE SECOND CERVICAL NERVE
Sends off,  from its Anterior Branch,  a twig which
descends to the lower cervical ganglion of the sympa-
thetic, and a considerable ramification to the third cer-
vical nerve.  It also sends off some twigs to the sterno-
mastoid muscle, and others to join the accessory nerve.
Some of its small ramifications pass  down  upon the
external jugular vein, and others  unite with the  de-
scending branch of the  ninth  pair of the head.   A
small  branch  is also concerned in the formation of the
phrenic nerve.  Two larger branches of this nerve
wind  round the posterior edge of the sterno-mastoid,
and are spread under the integuments of the anterior,
lateral and posterior parts of the neck and lower parts
of the head; they have a communication  with  the
portio dura of  the seventh pair.*—The  posterior
branch of this nerve is spent upon the extensor mus-
cles of the head and neck.
           THE THIRD CERVICAL NERVE

Sends down, from its Anterior Branch, the princi-
pal trunk of the phrenic nerve.   It also sends twigs
to the fourth cervical, to the lower cervical ganglion
of the intercostal, and to  the  descending branch of
the ninth of the head.   Some of  its branches, unite
with  twigs of the  accessory nerve, and  others  are
spent upon the muscles and integuments of the shoul-
der and lower part of the  neck.   A small Posterior
Branch is spent upon the muscles of the back of the
neck.

  * These superficial branches have sometimes  been described as coming
from a plexus ; but they often arise directly from the Second Cervical
nerve.
  Vol.  ii.              44 
346             Cervical Nerves.
         THE NERVES OF THE DIAPHRAGM

Are generally denominated the Phrenic.  The prin-
cipal root of each of them is commonly derived from
the third cervical nerve, but frequently the second and
the  fourth  cervical nerves  contribute to the forma-
tion ; and they are sometimes joined by a twig which
is derived from the ninth pair.
  Each nerve proceeds down the neck? between the
rectus  capitis major and  the  scalenus anticus, and
continues along the fore part of the scalenus anticas;
it descends into the thorax within the anterior end of
the first rib, between the subclavian vein and the ar-
tery.  It sometimes receives a twig  from the fifth cer-
vical nerve, and a twig passes between it and the great
sympathetic.  After entering the thorax, they descend,
attached  to the mediastinum, before the root of the
lungs.   In consequence of the projection of the point
of the heart to the left, the course of the left is a little
different from that of the right; that of the right pro-
ceeding in a more perpendicular direction.  When
they arrive at the diaphragm, they divide into many
ramifications, which have a radiated arrangement, and
terminate on  the fibres of that muscle, both on the
upper  and lower surface.   Some  fibres from  each
nerve are continued downward, and communicate in
the abdomen with fibres from the intercostal.

THE FOURTH, FIFTH, SIXTH, AND  SEVENTH CERVI-
                  CAL NERVES,

May be comprised in  one description.  They pass
off  successively from the Medulla Spinalis, between
the vertebrse, like the other nerves.  Their Posterior
Branches are generally distributed  to the back of the
neck, and are very small.   Their Anterior Branches
are principally appropriated to  the upper extremi-
ties, and are  large.  They generally send each a 
Remaining Cervical Nerves.—Brachial Plexus. 347

small twig to the lower cervical ganglion of the inter-
costal nerve, and a few small branches to some of the
contiguous  muscles.   They are arranged and com-
bined so as to form the net-work, now to be described,
which  is called the Brachial or  Axillary plexus;
and, in the formation of this plexus, they are joined
by the first dorsal nerve.

          The BBACHIAL PLEXUS

Extends from the lower part of the side of the neck,
into the arm-pit.   It  commences in the following
manner.   The fourth and fifth cervical nerves pro-
ceed downwards, and after  uniting  to  each  other
about an inch and a half below their egress from the
spine, they separate again, almost immediately, into
two branches.
   The sixth cervical nerve, after passing downwards,
divides also into two branches, one of which  unites
with the uppermost  branch that proceeds from the
union of the fourth and fifth, and the  other with the
lowermost, and they all proceed downwards.
   The seventh cervical is joined by the first dorsal,
which proceeds upwards, and unites with it at a
short distance from the spine.  The cord produced  by
their junction soon unites with one of the cords above
described.  As these different cords proceed down-
wards, they divide,  and their branches again  unite.
The axillary artery, which passes in the same  direc-
tion,  is  surrounded by them.  In this manner the
axillary plexus is often formed.
   The muscles about the  shoulder, both  before and
behind, are supplied by the axillary plexus.   Thus,
it sends branches to the Subscapularis, Teres Major,
and Latissimus Dorsi, behind; and to the Pectora-
lis Major and Minor, and the  Mamma, before.  It
also sends off  a branch called the Scapularis,  which 
348           Nerves of the Arm.
commonly arises from the upper part of the plexus,
and proceeds through the notch in the upper  costa
of the scapula,  to the supra and infra spinatus,  teres
minor, &c.
               Nerves of the Arm.

  All the great nerves of the arm are derived from
the axillary plexus.  There are six of them, which
are denominated The Musculo Cutaneous ; the Me-
dian ;* The Cubital, or Ulnar;  The Internal Cu-
taneous;  The Radial or Muscular Spiral; and the
Circumflex or Articular.
  The Musculo Cutaneous, or Perforating Nerve,
passes obliquely through the upper part of the coraco
brachialis muscle.  Before it  enters the muscle,  it
sends a branch to it.   After leaving  the muscle, it
passes down  the arm  between the biceps and the
brachialis internus, to which  it also gives branches.
It proceeds to  the outside of the  biceps, and  conti-
nues under the median cephalic vein to the anterior
and external part of the  fore-arm ; along which  it
passes, under the  integuments.  On the lower part
of the fore-arm it divides into many branches,  which
extend to the root of the thumb and the back of the
hand, and terminate in the integuments.
  The Median Nerve, which is one of the largest of
the arm, often proceeds from the axillary plexus next
to the musculo  cutaneous; it  passes down the arm,
very near the humeral artery, within the edge of the
biceps flexor muscle, and, during  this course,  gives
off no branches of any importance.   After  passing
the bend of the elbow, it proceeds,  under the apo-
neurosis of the biceps, between the  brachialis inter-
nus and the pronator teres, and continues down near
* Sometimes called Radial 
      Median and Cubital or Ulnar Nerves.   349

the middle of the fore-arm, between the flexor subli-
mis and the flexor profundus.  At the elbow it sends
branches to several  muscles  on the anterior side of
the fore-arm, and to the integuments.  Among these
branches is one, called the Interosseal Nerve, which
passes  down on the anterior surface of the interos-
seal ligament, with  the  artery of that name.   This
nerve sends branches, in its course, to the long flexor
of the thumb and the deep flexor of the fingers.
When it arrives at the pronator quadratus, it sends
branches to that muscle, and, passing between it and
the interosseous ligament, perforates the  ligament,
and soon terminates on the posterior side of the wrist
and hand.
   As the Median Nerve proceeds downwards, it be-
comes more  superficial; and continuing among the
tendons of  the flexors of the  fingers, it gives off a
branch which is principally spent upon the integuments
of the palm of the hand.  This great nerve passes with
the tendons under the annular ligament; and imme-
diately after, while  it is covered  by the Aponeurosis
Palmaris, and by that portion of the artery which is
called Arcus Sublimis, it divides into branches, which
separate from each  other at acute angles, and subdi-
vide so as to  send a ramification to each side of the
thumb, of the index,  and of the  middle finger; and
to the radial  side of the  ring finger.
   The Cubital or Ulnar Nerve  is also of considera-
ble size. It passes down on the inside of the triceps
extensor muscle, to  the great groove formed by the
olecranon process and the internal condyle of the os
humeri; and in this course it often sends a branch to
the triceps, and some  smaller twigs to the upper part
of the fore-arm.  From the groove it proceeds on the
anterior part of the fore-arm, between the flexor carpi
ulnaris and the flexor sublimis, to the wrist.   At a
small distance above the  wrist it  sends off  a branch. 
350    Radial, or Muscular Spiral Nerve.

called the Dorsalis, which passes between the flexor
ulnaris and the ulna, to the back of the fore-arm and
wrist, where, after sending ramifications to  the inte-
guments and contiguous parts, it divides into branches
which pass to the little finger and the finger next to
it.  Those branches'send off, in their course, many
twigs which  pass  to  the  skin  and  cellular sub-
stance.
  The ulnar nerve  then proceeds, with the artery,
over the annular ligament, on the radial side of  the
os pisiforme, and  divides into two branches;  one of
which is superficial, and the other deep-seated.
  The Superficialdivides'mto two principal branches,
an  external and  an internal.  The external passes
under the  aponeurosis palmaris; and, after sending
a branch to combine with one from  the median,  and
some twigs to the contiguous muscles,  it subdivides
into two branches,  one  of which goes to  the ulnar
side of  the ring finger and the  opposite side of  the
little finger.  The other branch sends off some twigs
to the muscles, and  proceeds along the ulnar side of
the little finger.
  The Deep-seated palmar branch of the ulnar nerve,
passes between the muscles of the little finger, under
the tendons of the flexors, and accompanies the deep-
seated arterial arch  in the palm  of  the hand, giving
branches to the interossei, and other contiguous mus-
cles.
  The Radial or Muscular Spiral  nerve is one of
the largest nerves of  the  arm.  It passes  from  the
axillary plexus downward,  backward  and  outward,
under the triceps muscle, to the external side of the
os humeri.  In this course it gives off several branches
to the different portions of the  triceps.  It also  fre-
quently gives off a large branch, which passes down-
wards on the outside of the  olecranon, to  the back
of the  fore-arm,  and continues to  the back of  the 
        Radial, or Muscular Spiral Nerve.    351'

hand, furnishing many branches whieh terminate  in
the integuments.   It  then proceeds downwards be-
tween the supinator radii  longus and the brachialis
internus.  Immediately after passing the articulation
of the elbow,  it divides into two branches, denomi-
nated the Superficial and  the  Profound.  The Su-
perficial soon  joins the radial  artery, and proceeds
downwards, sending branches to the contiguous mus-
cles.  In its course about  the  middle of the arm, it
crosses the tendon of  the  supinator longus, and pro-
ceeds between it and the tendon of the extensor carpi
radial is longior; it soon after divides the two branches,
which are principally distributed to  the thumb and
fore finger, and also to the integuments.
   The Profound branch proceeds to the back of the
fore-arm under the radial extensor, and continues to
the back of the wrist  and  hand.  Into this course it
divides into two branches, which are distributed to
the contiguous muscles and tendons, and the inte-
guments.
   The Internal Cutaneous  nerve is the smallest of
the nerves which proceed from  the  axillary plexus.
It descends in the course of the basilic vein, and
very near  it.   Above the elbow it divides into  an
Internal branch, which proceeds over the Basilic
 Vein, and separates into  branches that  pass  down
on the side of  the fore-arm; and an External Branch
that passes under the Median Basilic Vein, and con-
tinues down on the anterior part of the fore-arm.
   The Articular or Circumflex  nerve proceeds
backwards from the plexus, between the teres major
and minor, and passes nearly around the body of the
 os humeri, at a small distance below its head.   It is
 distributed to the contiguous muscles and to the arti-
 culation ; but its principal branches terminate  in the
deltoid muscle. 
352
The Dorsal Nerves.
          THE DORSAL NERVES
Proceed from the cavity of the spine between the
dorsal vertebrae.  They are sometimes called Inter-
costals, because they pass between the ribs, like the
blood vessels of that name.  There are  twelve pair
of them, and they are named numerically, beginning
from above.
   These nerves proceed  from the  medula spinalis
by two fasciculi of fibres—one from each of its late-
ral portions—the posterior fasciculus is  the largest.
After passing through the  lateral foramen and the
dura  mater, a ganglion  is  formed by the posterior
fasciculus: the anterior fasciculus unites to this gang-
lion  at  its external extremity: and one  nerve  is
formed, which almost  immediately divides into  an
anterior and a posterior branch, of which the  ante-
rior is the largest.
   The posterior branch proceeds backwards, and is
distributed to the muscles of the back. The anterior
branch passes towards the angle of the rib, in con-
tact with the pleura.   Soon after its origin, this an-
terior branch sends  off two ramifications which  unite
to the intercostal nerve, at the ganglion; it then pro-
ceeds forwards with  the  blood vessels, between the
internal  and  external intercostal muscles, in the
groove near the lower margin of the ribs; and ter-
minates on the anterior part of  the  thorax.  In its
course it sends branches,  not only to the intercostal
muscles and  pleura, but to the other muscles and the
integuments of the  thorax.
   Some of the dorsal nerves differ from the others,
as to the ramifications which they send off.
   The first nerve, of this order, joins the lower cer-
vical nerves in the  axillary  plexus ;  but it sends  off
the ramifications to the  sympathetic;  and also a 
     General Account of the Lumbar Nwves.  353

branch, which  passes under the first rib, like  the
other dorsal nerves.
  The second nerve, sends off a branch, which passes
through the external intercostal  muscle  into the ax-
illa, and combines  there with a branch of the  cuta-
neous nerve, being distributed to the internal and
posterior part of the arm.
  The third dorsal nerve also  sends off a branch,
which is distributed to the axilla and  the back part
of the arm.
  These branches of the second  and  third dorsal
nerves, are called intercosto-humeral nerves.
  The lower dorsal nerves supply the  muscles and
integuments of  the abdomen.
            Of the LUMBAR Nerves.

  There are five pair of these nerves.  The first of
them passes off between the first and  second of  the
lumbar vertebras, and the others succeed regularly ;
so that the last  pair is situated between the last lum-
bar vertebra and the sacrum.
  The first lumbar nerves  arise from  the medulla
spinalis, before  it forms the cauda equina; the other
four pair are formed by the  cauda equina.
  They commence by anterior and posterior fascicu-
li, which are united at a ganglion. From these gang-
lion, anterior and  posterior  branches  go off, which
are very  different  in  size,  the anterior  being  the
largest.
  The posterior branches are distributed to the mus-
cles of the  back.  The anterior sends branches to the
ganglions of the sympathetic nerve, and  also commu-
nicate with each, other to form the Lumbar Plexus,
which is situated on the lateral parts of the bodies of
the Lumbar Vertebrae, before their transverse pro-
cesses, and supplies nerves to the muscles of the
thigh.
  Vol. il,             45 
354    Lumbar Nei'ves.—Lumbar Plexus.

            THE FIRST LUMBAR NERVE
Is connected, by its anterior branch, to the last dor-
sal and the second lumbar.  From  the same branch,
ramifications go off to the  Quadratus Lumborum, and
obliquely across that muscle, to the lower part of the
abdominal muscles near the spine of the ilium.
           THE SECOND LUMBAR NERVE
Sends  off a muscular branch downwards and  out-
wards :  it also sends off the small branch, called the
External Spermatic, which passes down in  such a
direction, that it perforates the transversalis and the
obliquus internus muscles, near their lower margin,
at a small distance from the superior anterior spine
of the ilium, and then proceeds within the lower edge
of the tendon of the external oblique to the abdomi-
nal ring, through which it passes.  In the male it is
distributed to the spermatic cord and scrotum, and in
the female, to the labia pudendi.   In  the  female it
also sends a branch to the uterus.*   The  Second
Lumbar, after sending  off these branches,  passes
downwards, and joins the  Third lumbar nerve.  From
this union of the second  and third nerves, a branch
called the Cutaneus Medius, which will be soon de-
scribed proceeds downwards.
   After sending off this branch,  the united trunk of
the second  and third joins the Fourth ; and from this
union is sent off the Obturator Nerve, which passes
through the aperture in the  membrane that closes
the foramen thyroideum; the  Crural Nerve,  which
passes under Poupart's ligament; and a third branch
that proceeds downwards, and joins the Fifth lumbar
nerve.  The  Fifth  lumbar nerve, with this acces-
sion from above, descends into the pelvis, and unites
with the sacral nerves.
* The external spermatic often comes off from the first lumbar nerve. 
         Obturator Nerve.—Crural Nerve.    355

This arrangement of the  lumbar nerves constitutes
the Lumbar Plexus, which, as has been already sta-
ted, furnishes three nerves to the lower extremity,
viz. the Cutaneus Medius,  the Obturator,  and the
Crural Nerve.
  The  Cutaneus  Medius, which arises from the
union of the second and third nerves,  as has  been
already observed,  proceeds downwards, and fre-
quently adheres to the crural nerve,  for a short dis-
tance, near Poupart's ligament,  but soon leaves it,
and descends on  the inside of the thigh,  supplying
the integuments as low as  the knee.
             THE OBTURATOR NERVE
Descends into  the pelvis,  and  passes out of it at the
upper part of the foramen thyroideum ; proceeding
downwards in an internal direction, to be distributed
on the inside of the thigh.
  This nerve  is generally accompanied by the obtu-
rator artery and vein ; the artery being above, and
the vein below it.   When it has arrived at the fora-
men ovale or thyroideum,  it sends  off a  branch  to
the internal and external obturator  muscles,  and,
after passing these muscles, divides into two branches
which are distributed to the muscles  on the inside of
the thighs, the adductors, the pectineus,  the graci-
lis, &c.
               THE CRURAL NERVE

Is situated at first behind, and then on the outside of
the psoas muscle. •  It passes under  Poupart's  liga-
ment with the great femoral vessels, being on the
outside of the artery.
  It is distributed  to the integuments, and also  to
the muscles, which  are  situated on the anterior and
internal parts of the thigh.  Some of its ramifications
go  off before  it passes under Poupart's  ligament. 
356      Crural Nerve.—-Sacral Nerves.

Several of them are spent upon the integuments, and
are  therefore  denominated  Cutaneus.—They  are
distinguished by the terms Cutaneus Anterior, Cu-
taneous Internus, &c. according to their situations.
   The deep-seated branches are the largest.   They
are principally spent upon the muscles on  the ante-
rior and the internal  side of the thigh, viz. the four
extensors, the adductors, the pectineus, thesartorius,
and the gracilis.   Among these nerves there is one,
called the Sqphenus, which has a different destina-
tion.  It accompanies the great artery of the thigh to
the place where it perforates the Adductors : it there
separates from the artery, and passes over the tendon
of the Adductors, under the sartorius muscle; thence
it continues, with the great saphena vein, on the in-
side of the leg, to the internal ankle; sending branches
to the integument, in its course.  It terminates in skin
and cellular substance on the upper and internal sur-
face of  the foot.

              The SACRAL Nerves

Are composed of those  cords of the cauda  equina,
which remain after the  formation  of the  lumbar
nerves.   They are  frequently  stated to  consist  of
five or six  pair,  four of which  pass through the fo-
ramina of the sacrum, and  the  fifth  between the sa-
 crum and  the os  coccygis.*   The  cords of which
 they are respectively composed arise  by anterior and
 posterior fasciculi.   When they have  arrived oppo-
 site to the foramina of the sacrum, through which they
 are to  pass,  a ganglion  is  formed,  at which  they
 unite, and then  divide  into  anterior  and posterior
 branches.t  The uppermost of the anterior branches

   * The sixth pair, when  they exist, 'proceed in a groove in  the os
 coccygis.
   t The ganglions of the fourth and fifth nerves are txtremelv small  and
 not so near tiie foramina as those of the others. 
          Sciatic PJexus.—Pudic Nerve.      357

are large and pass through the anterior  foramina of
the sacrum.  The posterior are small, and go through
the posterior foramina.
  The Posterior branches are generally spent upon
the muscles  which lie on the sacrum, and  posterior
parts of the pelvis, externally.
  The anterior branches of the three  first nerves
send ramifications to the sympathetic.  They unite to
each other,  and are joined by the last lumbar nerve,
and by a branch of the fourth sacral, in the forma-
tion of the great sciatic nerve.  This union constitutes
the Sciatic  plexus.
  The anterior branch of the fourth nerve transmits
branches to  the sympathetic: it also sometimes sends
a branch  to the united nerves above, or the sciatic
plexus.  It  sends branches to the hypogastric plexus,
and to the contiguous muscles.
   The fifth and  sixth pairs, which are very small,
terminate also in the contiguous muscles and  in the
integuments.
   From the Sciatic plexus, or the nerves which com-
pose it, several smaller branches go  off.  There are
generally two^which pass off backwards through the
ischiatic notch, and are denominated Gluteal, as they
 are distributed to the glutei muscles.  From the low-
 ermost of these a branch descends on the thigh.
    The Pudic  nerve, which is appropriated to the or-
 gans of generation, also passes off from  this plexus,
 and appears to consist of fibres which  are derived
 from each of the nerves that compose it.  It proceeds
 between the sacrosciatic  ligaments, and divides into
 two branches—an inferior and a superior.   The in-
ferior passes between the erector  penis and the ac-
 celerator urinse  muscles, and is  distributed to those
 muscles,  to the bulb of the urethra  and the interior
 of that canal, to the scrotum and dartos.
    The superior proceeds along the os pubis to the 
35S     Course of the Great Sciatic Nerve.

symphisis, and passes between the bone and the body
of the penis to the dorsum.  A considerable branch
accompanies the artery on the dorsum, and terminates,
by many ramifications, on the glans penis; after send-
ing branches in its course  to the integuments gene-
rally, and to the prepuce.
  In females, the Inferior pudic nerve proceeds along
the external labia pudendi to the mons veneris, send-
ing off many ramifications in its course.
  The Superior pudic  nerve proceeds, as in males,
along the branch of the pubis to the superior surface
of the clitoris, and terminates principally upon  the
extremity of that organ.
  The sacral nerves unite in the sciatic plexus to
form the great nerve of  the lowe# extremity, which
is next to  be described.

          The GREAT SCIATIC Nerve

Proceeds from the pelvis through the ischiatic notch,
between the pyramidalis and the  superior  gemellus
muscle: it then passes down to the back part of  the
thigh, between the tuberosity of the ischium and  the
great trochanter  of  the os femoris;  and continues
downwards, inclining from within outwards,  to  the
ham, where it is situated between the  tendons of the
semi-tendinosus and semi-membranosus on the inter-
nal side, and the tendon of the biceps on the external.
In this course it sends off branches to the muscles on
the posterior part of the thigh.
  As the great nerve passes down the  thigh, it sends
off obliquely downwards  and outwards,  a  large
branch  which  is  called  the  Fibular, that passes
across the head of the fibula  to the external and
anterior part of  the leg.   The place where this
branch separates from the  main  nerve  is different in
different subjects.  It continues in contact with it 
        Distribution of the Fibular Nerve.    359

for some distance, connected only by cellular mem-
brane.
        THE FIBULAR OR PERONEAL NERVE

Proceeds downwards on the inside of the tendon of
the biceps, and crosses obliquely to the outside of the
external head of the  gastrocnemius:  it then  passes
inwards between the long peroneus muscle  and the
fibula; and descending between the muscles on the
front of the leg, divides  into two branches,  one of
which inclines  to the exterior side of the leg, and
the other preserves an internal situation.  In its course
from the great sciatic nerve to the fibula, it sends off
some superficial  ramifications.   The two branches
into which it divides, after passing over the  fibula,
continue downwards.  The Internal, after supply-
ing the  musdes on the anterior  part  of the  leg,
passes under the annular  ligament like  the  anterior
tibial artery; and on the  upper part of the foot, di-
vides into two ramifications, one of which proceeds
forwards near the internal edge of the foot, and the
other near the  external;  they divide again, and are
distributed to  the parts on the upper surface of the
foot, one of their ramuli  descending with the conti-
nuation of the anterior tibial artery to the sole of the
foot.
   The  External Branch of the fibular  nerve, as it
proceeds downwards,  supplies  ramifications  to the
contiguous  muscles, and  passing through the fascia
on the outside of the leg, continues between  it and
the skin towards the foot.  In  this course  it gene-
rally divides into two branches which are spent upon
 the upper surface of the  foot.
   The  GREAT SCIATIC Nerve, after the fibular
 nerve leaves it,  continues down the thigh, between
 the tendons of the flexors, behind the great blood
 vessels, and of course exterior to them. 
360    Distribution of tlie Tibial Nerve.

   In the  ham, this great  nerve takes  the  name of
POPLITEAL, and proceeds across the articulation
of the knee, between the heads of the gastrocnemii,
to  the  posterior side of the tibia:  here it passes
through the upper portion of the soleus or  gastroc-
nemius  internus, and continues  between it  and the
long flexor of the toes, near the Posterior Tibial Ar-
tery; descending with that artery to the hollow of the
os calcis.  In this situation  it has the name of

             POSTERIOR TIBIAL NERVE.

   At the  commencement of this course, a small dis-
tance below the internal condyle of  the  os  femoris,
it sends off a branch of considerable size called the
Communicans  Tibx, or Saphena Externa, which
passes down  behind the gastrocnemii, and gradually
inclines externally, so that it is situated  on  the ex-
ternal edge of the tendo Achillis, soon after the  com-
mencement of that tendon, and proceeds behind the
external ankle, near the outer side of the foot, to the
smaller  toes: distributing branches to the contiguous
parts.   In its eourse on the back of the leg, it sends
off  a branch which unites with one of the superficial
ramifications of the fibular nerve, and descends to the
outer part of the  foot.
  The Tibial Nerve, in its course downwards, sends
branches to the contiguous muscles; and a few twigs
which form a species of net-work on the artery.   In
the hollow of the os calcis  it sends off  a superficial
branch  to the  integuments of the sole  of the  foot,
which proceeds on the outside of  the aponeurosis
plantaris:  it there also divides into branches, which
are denominated  the Internal and External Plantar
Nerves.
  The Internal Plantar Nerve proceeds forwards,
along side of the tendon of the long flexor muscle of
the great toe, giving off small branches in its course. 
    Commencement of the Sympathetic Nerve. 361

About the middle of the foot it  divides into four
branches,  one of which  proceeds to the inside of the
great toe; and a second to the angle formed  by the
great toe and the toe next to it, where it divides and
sends a branch  to  the opposite sides of those toes:
the other two branches  are  distributed in a  similar
manner, to the succeeding toes.  These digital branches
are connected with each other by small  ramifications.
  The External Plantar Nerve  proceeds with the
external plantar artery towards the externel  side of
the foot, between the short flexor of the toes and the
flexor accessorius.   Near the external edge of the
foot, about the posterior end of the metacarpal bones,
it divides  into three branches.   One proceeds to the
outside of the little toe; another  passes to the angle
between the fourth toe and the little toe, and divides
into branches which are distributed to the correspond-
ing sides of these toes.   The third branch proceeds
more deeply in the foot, from the external towards
the internal edge of it, and is spent upon the deep-
seated contiguous muscles.
THE GREAT SYMPATHETIC OR INTERCOSTAL  NERVE

Commences in the  cranium with those small ramifica-
tions of the pterygoid branch of the upper maxillary
nerve, and of the  sixth pair,  which accompany the
carotid artery through the canal in  the petrous portion
of the temporal bone.   These small nerves  from a
net-work which surrounds the artery in the canal, and
gives rise  to the incipient sympathetic, a small  cord
which passes down close to the nerves of the  eighth
and ninth  pair of the neck.  Opposite to the  second
cervical vertebra, this nerve is swelled  or dilated, so
as to form a body of a light red colour, which is more
than an inch in length, and has the form of two cones
united to each other at their bases.  This is the Su-
perior Cervieal Ganglion of the Sympathetic Nerve.
   Vol. ii.              46 
362    First- Ganglion, and other Cervical

and from it the nerve descends, behind the Par Va-
gum, on the front part of  the neck.
  This ganglion receives twigs from the first, second,
third and fourth pairs of cervical nerves, and also from
the eighth and ninth nerves of the head.  It sends off
several twigs,  which pass behind the carotid artery,
at its bifurcation, and are joined by twigs of the Por-
tio Dura and the Glosso-Pharyngeal nerves.  From
these united twigs proceed very small ramifications,
which  accompany several  branches  of the external
carotid artery, and some of them pass down with the
Common Carotid.
  This superior ganglion  also furnishes small twigs
which accompany theGlosso-Pharnygeaho the tongue
and pharynx.   Sometimes a  twig from it passes on
the back part of the  thyroid gland to communicate
with the recurrent nerve.  From this ganglion go
off some small branches, which, uniting with others
from the  superior laryngeal nerves,  form  the supe-
rior or superficial cardiac  nerve, which will  be soon
described.
  The trunk of the Sympathetic Nerve descends, on
the front of the neck,  from this ganglion, as has been
already stated.  In its course it receives very small
twigs from the  fourth and fifth  cervical nerves, and
sends some  very small  twigs  which appear to go
to the cesophagus, and some which unite to  the la-
ryngeal nerve  and  go to the  thyroid gland.   Some
twigs,  which are larger, proceed from it into the
thorax, and go to the cardiac  plexus hereafter to be
described.
  Opposite to the interval between  the  fifth and
sixth cervical vertebree it forms another ganglion, of
an irregular shape, much smaller than the first.  This
ganglion, in  different  subjects, differs in size as well
as in several other respects.   Sometimes it is en-
tirely wanting, and sometimes it is  doubled.  It is 
 Ganglions and Branches of the Sympathetic. 363

denominated the Middle Cervical, or Thyroid Gan-
glion.   When the fourth, fifth, and sixth cervical
nerves do not send ramifications to the sympathetic
nerve, this ganglion receives twigs from them.
  The Middle Cervical, or Thyroid. Ganglion sends
many ramifications downwards.  Some of them enter
the thorax and contribute to  the formation  of the
Cardiac Plexus;  others  accompany  the inferior
thyroid artery, and, with  twigs from the  recurrent
nerve, form  a plexus which extends towards the
thyroid gland.   Some proceed downwards before,
and others behind, the subclavian artery, to the next
ganglion; and among them  is generally one  which
may be regarded as the trunk of the Sympathetic.
  This third Ganglion is  denominated the Inferior
Cervical, or the First Thoracic.  It is almost Con-
stantly found in the same situation, viz. between the
transverse process of the  last cervical vertebra and
the head of the first rib, and is partly covered by the
origin of the vertebral artery.   It is generally larger
than the middle ganglion.   It receives branches from
the sixth and seventh cervical, and the two first dor-
sal nerves.  Ramifications  pass from it to the par va-
gum and recurrent  nerve, and also to the cardiac and
pulmonary plexus.
   From this ganglion the Sympathetic Nerve  pro-
ceeds downwards on the side of the spine, as  will  be
described hereafter.
             The Nerves of the Heart,

Being derived from branches which have already been
mentioned, are now to be  described.
   They arise principally from  an arrangement  of
nerves denominated the Cardiac  Pltxus,  or Plex-
uses, which is situated above the curve of the aorta,
and extends,  on  the posterior side of it, from the
root of the arteria  innominata to the bifurcation  of 
 364       Branches of the Sympathetic.

 the pulmonary artery.  This plexus is composed of
 nerves  which are principally formed by  the  union
 of small ramifications that are derived from the three
 above mentioned ganglions of the Sympathetic Nerve,
 and the nerve itself;  and also from the Par Vagum
 and some of its branches.
   These nerves  are  denominated  the Cardiac.—
 They descend on their respective sides of the neck,
 but are somewhat different on  the different sides.—
 On the right side three nerves  have been described
 as particularly entitled to this name, and on the left
 side but two.
   The  first on the right side is denominated Supe-
 rior,  or Superficial Cardiac Nerve.  It generally
 arises by several fine threads, which unite into  one
 delicate cord that passes down by the side of the
 common carotid.    When  it has arrived  on a line
 with the middle ganglion, it sends a twig to the thy-
 roid plexus, and another  that communicates with  a
 twig from the par vagum, which  continues downwards
 on the carotid artery.  After passing beyond the gan-
 glion, it divides into several branches, which  unite
 themselves  to branches of the recurrent nerve that
 are going to the middle ganglion.
  The second,  which  is denominated  the  Middle
 Cardiac, the Great Cardiac, or the  Deep  Cardiac,
 is the largest of the three.  It  arises from the Mid-
dle Cervical, or  Thyroid Ganglion, by five  or six
 fine fibrils,  which finally form one, that passes before
and across the subclavian; and at that place as well
as lower down, it receives twigs from the par vagum:
below this,  it is joined by a considerable  twig from
the recurrent, and terminates in the Cardiac Plexus,
to which it  contributes largely.
  The third cardiac nerve of the right side is called
the Inferior, or the Small Cardiac Nerve.   It ori-
 ginates from the third, or lower cervical ganglion, by 
Branches of the Sympathetic.
365
many fibrils which unite into a smaller number that
form a plexus.  It crosses  behind the subclavian,
and proceeds on the outside of the Arteria Innomi-
nata to the curve of the  aorta; continuing between
it and the pulmonary artery,  to the anterior corona-
ry plexus.   In this course it receives  several fibres
from the recurrent and the par vagum.
  On the left side the first cardiac nerve arises from
the upper ganglion.   The  second derives its origin
from the two lower ganglions.
  The left superior or superficial cardiac nerve arises
like the right, by many distinct fibres, and proceeds
downwards  in  the same way.   It descends between
the carotid and the subclavian, and when it has ar-
rived at the place where they originate from the aorta,
it divides into a great number of small ramifications.
Some pass before the aorta, either to join the branches
of the  inferior cardiac, or to unite with the cardiac
branches of the left nerve of the par vagum.   The
others proceed  behind the aorta,  and  enter into  the
common cardiac plexus.
  The second cardiac nerve of the left side may be
called  the  Great  Left  Cardiac, and has a double
origin as above  mentioned.   The principal branch
in its  composition arises from the lowest  cervical
ganglion, and passes  behind the  transverse  portion
of the subclavian artery.  Where the inferior thyroid
arises  from the subclavian, this branch  receives a
considerable  number of ramifications, which arise
from the upper ganglion, and  are interwoven with
each other before they unite to it.  It passes behind
the curve of the aorta,  and terminates in the great
cardiac plexus, which  it particularly contributes to
form.  Here it is joined by many fibres from  the
par vagum. 
366  Plexus formed by the Nerves of the Heart.

               The Cardiac Plexus

Is situated principally behind the curve of the aorta,
at a small distance above the  heart.   It commences
as high as the origin of the Arteria Innominata, and
extends downwards to  the bifurcation of the pulmo-
nary artery.
  As has been already mentioned, it  is principally
composed of branches from the middle eardiac nerve
of the right side, and the inferior  cardiac nerve  of
the left; but it receives branches from the superior
cardiac of the left, and sometimes of  the right side.
Some fibres of the  inferior cardiac of  the  right are
also united to it.
  Many branches proceed from this plexus.
  A small number  pass upon the aorta, and seem to
enter into its texture.*
  Some of them also combine with the ramifications
of the Par Vagum in the anterior pulmonary plexus.
  The majority proeeed to the basis of  the heart,
near the origin of the pulmonary artery and the aorta,
and constitute the proper nerves of that organ.  They
accompany the coronary arteries, and are so arranged
around  them  that, by some anatomists,  they have
been said to form plexuses, which  have been deno-
minated Coronary.
  The Sympathetic Nerve, as has been stated above,
proceeds from the ganglion, called the Lower  Cer-
vical, or the First  Thoracic, before the neck of the
first rib.  It continues to descend, in the same direc-
tion, along the spine, exterior to the pleura,  to the infe-
rior part of the thorax.  Near the head of each rib it
forms a ganglion, which  unites with the  intercostal
nerve behind it, by two branches,  and thus forms an
indirect communication with the medula spinalis.
 * It has been asserted, that some of the anatomists of Paris have traced
these nerves on the aorta, to a great distance from the heart. 
Sympathetic Nerve, fy its Splanchnic Branches. 367

  From several of the uppermost of these ganglions,
small  twigs proceed to  the  pulmonary plexus, and
also to the great trunk of the aorta, below the curve,
forming a species  of net-work, or plexus, upon it.
  From the ganglions near the heads of the fifth and
sixth  ribs, and from four or five of the  ganglions
which succeed them,  small nerves arise, which pro-
ceed downwards  on  the sides of the bodies of the
vertebrse, and  unite into one trunk that is denomi-
nated the Splanchnic Nerve, because it is distributed
to the viscera of the abdomen.—This nerve proceeds
behind the crus of the diaphragm, on its respective
side,  into the abdomen.  A second and smaller nerve,
of the same destination, called the Lesser Splanchnic
Nerve, arises lower down, from two or three of the
lowermost dorsal  ganglions, and penetrates separate-
ly into the cavity of the abdomen : it then generally
divides into two branches, one of which unites  to the
great splanchnic nerve, and the other proceeds  to the
renal plexus soon to be described.
   As soon as the great splanchnic nerve has entered
the abdomen, it divides into many branches, which
commonly form small  ganglions on each side of the
cceliac artery, but above it.  These ganglions are
generally contiguous;  but sometimes they are at a
small distance from each other, and united by nerves.
They are, however, commonly spoken of as one, and
called the Semilunar Ganglion.  They are  of  ir-
regular forms, and  very different from each other in
size, as well as form.  Those formed by the  splanch-
nic nerve on one side are sometimes different from
those on the other.
   From this assemblage of ganglions proceed many
 small nerves, which are woven together so as to form
 a net-work denominated the Solar Plexus.
   This plexus is situated anterior to  the spine and
 the crura of the diaphragm ; behind the stomach and 
368    Arrangement of the Nerves of the

above the pancreas; and is extended upon the cceliac
and superior mesenteric arteries. Some ramifications
from the par vagum and the phrenic also join it.
  The  lower  part of the solar plexus, which  sur-
rounds more immediately the coeliac artery, is termed
the Coeliac Plexus.  From it net-works of nerves ex-
tend upon  the great branches  of the artery to the
organs which they go to.
  They extend to the  stomach, (although it is sup-
plied by the par vagum,) along the superior coronary
or gastric branch of the coeliac; and the fibres in their
composition being spread upon the coats of the sto-
mach, unite with the  branches of  the  par vagum,
which are also spread upon them.
  A similar  net-work,  denominated the  Hepatic
Plexus, extends upon the Hepatic Artery, and from
it to the Vena Portarum; and accompanies those
vessels into the substance of the liver.  It also sends
branches to the biliary duct and gall  bladder; to the
stomach by the arteria  gastrica dextra ; and to the
omentum.
  The  Splenic Artery is invested by a similar but
smaller arrangement of nerves,  denominated  the
Splenic Plexus.  In its course to the spleen,  this
plexus sends some  nerves to the pancreas ; and also
to the stomach and omentum, with   the left gastric
artery.
  The superior mesenteric artery is surrounded by a
net-work, which extends to it directly from the solar
plexus,  and is the largest of all which proceed from
that plexus.  The Mesenteric Plexus at first nearly
surrounds the artery, and proceeds with it between
the lamina of the mesentery.   In this course it sends
branches,  with the arteria colica dextra, to the trans-
verse portion of the  colon.   Between the lamina  of
the mesentery, it  sends ramifications with all the
branches of the artery, to the small  intestines gene- 
Abdominal Viscera.
369
rally;  to the ccecum, and the right portion  of the
colon ; as well as to the mesenteric glands.
   From the lower part of the solar plexus a net-work
proceeds, on the front of the aorta, to the inferior
mesenteric artery, and surrounds it.  Nerves from
this  plexus accompany the artery to  the left portion
of the colon and the rectum.  Some of their ramifi-
cations combine with those of the hypogastric plexus.
   The Emulgent Artery is attended  by nerves, which
are arranged like a net-work on its anterior and poste-
rior  surfaces, and are denominated the Renal Plexus.
They are derived from the  solar plexus,  and fre-
quently  contain  small  ganglions.   They proceed
with the artery to the fissure of the kidney, and are
distributed with  its different ramifications,  in  the
substance of the organ.
   Some branches pass from them to the renal gland
with the capsular artery.
   Before the renal plexus arrives at the kidney, it
sends off, from  it0 inferior  part, some new fibres,
which, after joining  some others from one  of the
lumbar nerves, accompany the spermatic arteries, and
are,  therefore, called  the Spermatic Plexus.  In the
male these fibres proceed through the abdominal
ring, and many of them  go  to the testis,  but they
are followed with great difficulty,  on account of their
small size.
   In the female, they go to the ovary and the fallo-
pian  tube.
   From the great plexuses above, a small net-work
continues downwards on the  aorta,  receiving fibres
from the intercostals on each side ; at the great bifur-
cation of the aorta it divides, and is joined on each
side  by many ramifications from  the third  lumbar
nerves,  which thus form a  plexus of considerable
extent, that sends nerves to the bladder, rectum, and
vesiculse seminales in males;  and  to  the uterus and
   Vol. ii.              47 
370  Termination of the Sympathetic Nerve.

vagina, as well as  the bladder and  rectum, in fe*
males.*   This is called the Hypogastric Plexus. m
 ' The plexuses above mentioned are derived  from
the splanchnic nerve, which came off from the Sym-
pathetic in the thorax.
  The Sympathetic Nerve, after giving off the lesser
splanchnic, is diminished in  size, and approaches
nearer to the bodies  of the vertebrae.   It passes
through the crura of the diaphragm, and then pro-
ceeds forwards and downwards upon the spine, be-
tween the tendinous  crura of the  diaphragm and
psoas muscle; near the vena cava on the right side,
and the  aorta on the left.   In this  course, it gene-
rally receives one or two small cords from the  ante-
rior branch of each of the lumbar nerves: these cords
proceed downwards and forwards, between the bo-
dies of  the vertebrae and the  psoas  muscle,  and a
ganglion is generally formed at the plaee where they
join the nerve.
   In its descent on the  lumbar  vertebrae, the  Sym-
pathetic sends off several  nerves  that  unite to the
net-work which descends on the aorta from the plexus
 above.  After passing over the  lumbar vertebrae,  it
 descends into the pelvis, close to the sacrum, on the
inner side of the great  foramina: here it also  forms
 ganglions, and communicates with the sacral nerves,
 and likewise  with the hypogastric plexus.   It termi-
 nates on the  os coccygis, where its minute fibres join
 those of the  opposite side.

   * Although the  testicle receives nerves which are derived from the Sym-
 pathetic, the penis and other external parts ef the organs of generation do
 not: the nerves which accompany thepudic artery being derived from those
 which unite to form the great Sciatic. 
SYSTEM  OF ANATOMY.

                PART XI.
          OF THE ABSORBENT VESSELS.*

  The absorbent vessels are small transparent tubes,
of a delicate structure,  which exist  in  considerable
numbers in almost every part of the body.
  These tubes originate upon the surfaces of all the
cavities of the body;  and of  the cellular membrane,
in all the various parts into which it penetrates; upon
the  internal surface of the stomach and the intes-
tines ;  and probably upon the skin.
  Those which originate in the Lower Extremities
and the Cavity of the Abdomen, unite and form a large
trunk  called  the  Thoracic  Duct, which proceeds
through the thorax,  and terminates in the left Sub-
clavian Vein,  at its junction with the Internal Jugu-
lar.   Those of the Left Upper Extremity, the Left
Side of the Head, and  the contiguous parts,  form a
trunk which  terminates in the same place.  While
the remaining absorbents, or  those of the Right  Up-
per Extremity,  and  the  Right side of the Head,
fyc.  also form  a trunk, which terminates in the cor-
responding part of the Right Subclavian Vein.
  The absorbent vessels of the  middle  size, which

  * Discovered at Leyden in 1650, byOlausRudbeck, and at Copenhagen
irt 1651. by Bartholine.—Er>.                                      < 
372    Structure of the Absorbent Vessels.

arise from the union of  the  small vessels,  and unite
to form the larger, in their progress to these large
vessels, pass through certain bodies which have been
denominated  Conglobate Glands, and  may be consi-
dered  as appendages of the  absorbent system.
   The absorbent vessels are composed of  two coats,
which are thin,  but dense and firm, and also elastic.
The coats  of the  thoracic  duct may be  separated
from each other.  The internal  surface of the exte-
rior coat is fibrous.  The internal coat is  a delicate
but strong membrane.—There is great reason to be-
lieve  that the above mentioned fibres  are muscular,
or at  least irritable : for the absorbent vessels have
been  observed,  by Haller, to contract upon the ap-
plication of strong sulphuric acid.  They have also
been  observed to propel their contents with consider-
able rapidity, by their own contraction, independent
of pressure, or of motion communicated by any other
body.
   Blood vessels are sometimes observable  in the
coats of  the larger absorbents, in injected  subjects.
The vascularity of these tubes  may also be inferred
from  the inflammation which frequently takes place
in them.
   Nerves have  not been traced  into their texture ;
 but the absorbents seem to be painful when they are
inflamed, and, therefore, it is probable that they are
 supplied with nerves.
   The absorbent vessels are very generally supplied
 with valves,  which are  much more numerous in some
 of them than in others; and are different in their
 number, in the same vessels, in different subjects.
   Very frequently there are  several valves in  the
 course of an inch  : sometimes a  valve will not appear
 in the course of several inches. In the Thoracic Duct,
 the number   of valves is very different in different
 subjects.  These  valves are folds or plaits of the in- 
       ^Commencement of the Absorbents.     373

ternal membrane,  and are of a  semi-circular form.
There are  commonly two of them together origina-
ting from opposite sides of the vessel.
  The absorbents are  generally somewhat dilated
on the side of the valve which  is  next to their termi-
nation, and this occasions their  knotted appearance
when they are injected.   The object of this valvular
structure seems to be the prevention of retrograde
motion of the contained fluid, in consequence of la-
teral pressure.
  Where the different trunks of the absorbents open
into the veins, there are one or two valves to prevent
the regurgitation of the blood into them.
  The valves of course prevent the injection of the
branches of these vessels from their trunks.—In some
animals the valves have sometimes been ruptured, or
forced back; and  the absorbents have been injected
in  a  retrograde direction.   There are but two or
three instances upon record  where  this  has  been
practicable in  the Human Subject.
   In consequence of the impracticability of injecting
 the small  branches  from the larger,  the absorbent
 vessels  cannot, generally, be demonstrated at  their
 commencement, or origin. It is, however, to be ob-
 served, that the Lacteals, or Absorbents of the Intes-
 tines, appear no way different from other absorbents;
 and they have been seen distended with chyle, from
 their commencement,  in certain subjects  who had
 died suddenly.   Their  origins  have been described
 very differently by different observers.
    Mr. Cruikshank describes them as originating on
 the surfaces of the villi,  by a number of very small
 radiated branches with open orifices; which  branches
 soon unite to form a trunk.
    Lieberkuhn believed them to commence in the form
 of an ampullula.—Seepage 105 of this volume.
    The second Monro also believes that the absorb- 
374            Conglobate Glands.
 ents begin by very small tubes, with open orifices, in
 several species of fish.*
   It is stated by Dr. Soemmering upon the authority
 of Haase, a German anatomist, that when mercury is
 forced backwards in the absorbent vessels of the foot
 and the heart, it has sometimes escaped  on the sur-
 faces of those parts.  The probable inference from
 these  facts is, that those vessels  originate by open
 orifices on the surfaces of the heart and foot.
   The bodies connected with the  absorbent vessels,
 which are called Conglobate Glands, are generally
 of a roundish, or irregular oval form, and somewhat
 flattened.   They are of various sizes, from two lines
 in diameter to more  than  twelve.   Their colour is
 frequently whitish,  but sometimes it is slightly in-
 clined to red.  They are invested with a covering of
 cellular membrane, which appears like a membranous
 coat; and they are connected to the contiguous parts
 by a loose cellular  substance.   When the absorbent
 vessels connected with these bodies approach near to
 them,  they  divide  into a  number of ramifications,
 most of which enter into the substance of the  gland,
 while some of them run over it.  On the  opposite
 side of the gland  a number of branches go out,  which
 unite  and form trunks similar to those which entered
 the gland.  The vessels which  enter the gland are
 called  Vasa inferentia, and those which go out of it
 Vasa  efferentia.
   These vessels  are generally much convoluted in
 the substance of  the glands,*so  that those  bodies
 sometimes appear like a mere convolution of absorb-
 ent vessels.   There has been much diversity of sen-
 timent respecting the structure  of  these organs.f

  * See his work on the Structure and Physiology of Fishes, p. 34.
  f Mr. Abernethy states, that the mesenteric gland of the Whale con-
sists of large spherical bags into which a number of the lacteals open.—
Numerous blood vessels are ramified on the surfaces of these cvsts • 
Fluid contained in the Absorbents.     375
  The absorbent vessels, in the different parts of the
body, generally contain fluids resembling those which
are found in those  parts.   Mr.  Hewson  opened  the
large absorbents in many  living animals of different
kinds, and  found  that  they contained a transparent
fluid, which coagulated when exposed to the air.
  The  arrangement of these vessels  resembles that
of the veins in several respects.  Many of them are
superficial; but there are also deep-seated absorbents
which accompany  the blood vessels.

and injection passes from  them into  the cyst.  He also found cells in the
glands of the absorbent vessels, in the groin and the axilla of the horse.__
See Philosophical Transactions, for 1796, Part I. 
CHAPTER I.
 OF THE ABSORBENTS OF THE LOWER EXTREMITIES,
         THE ABDOMEN, AND THE THORAX.

   Under this head are arranged the ramifications of
 all the vessels which unite to form the Thoracic Duct.

                    SECTION r.

   Of the Absorbents of  the Lower Extremities.

   These absorbents, like the veins,  are superficial
 and deep-seated.   The Superficial lie in the cellu-
 lar membrane, very near  the skin; and form an irre-
 gular net-work which extends over the whole limb.
 They are, however, most numerous on  the internal
 side.
   The Deep-seated accompany the arteries  like the
 veins, and there are two at least to each artery.

            The Superficial Absorbents

 Have been injected from the toes so as to form a
 net-work, which occupies the upper surface of the
 foot.   They have  also been injected in a similar
 manner on the sole.  Those on the upper surface of
 the foot  generally proceed upward on  the  anterior
 and inner side of  the leg; but some of them pass on
 the external side of it.  Those on the sole are con-
tinued on the back of the leg, but communicate very
frequently with the anterior vessels.   Some of the
absorbents from the outside of the foot and leg enter
into  some of  the popliteal  glands, soon to be  de-
scribed ; but they are not  numerous; and the princi-
 pal number continues up to the glands of the groin. 
       Absorbents of the Lower Extremity.    377

The absorbents  which originate  on the surface  of
the thigh, as well  as  those which pass over it from
below, incline gradually along the anterior  and pos-
terior surface, to the internal  side of it; on which
they proceed, in great numbers, and very near to each
other, to the inguinal glands.   Superficial absorbents
proceed also from the buttock and lower  part of the
back, from the lower part of the abdomen, the peri-
neum and the  exterior of the genital organs, to these
glands.
           The Deep-seated Absorbents
Are named from the arteries they accompany.

         The Anterior Tibial Absorbents.
  The anterior tibial artery is generally attended by
one which comes with it from the sole, and by another
which commences on  the upper surface of  the  foot.
The first  mentioned absorbent continues with the ar-
tery.  The last often passes through an .aperture  in
the interosseal ligament, about  one-third  of the dis-
tance from the ankle to the knee, and accompanies the
fibular artery, while the anterior tibial artery is join-
ed  by other absorbents about the same  place.    In
some instances a small absorbent gland occurs in this
course, at a short distance below the knee.
         The  Posterior Tibial Absorbents

Have been injected from the under side of  the toes.
They accompany the ramifications on the sole of the
foot; and after uniting, continue with the main trunk
up the leg, where they enter the popliteal glands.
  The  Peroneal Absorbents arise also from the sole
of the foot, and  its external side.   They accompany
the  peroneal artery, and terminate in the popliteal
glands, which receive also  the absorbents  from the
knee and  ham.
  Vol. ii              48 
 378   Absorbents of the Lower Extremity.

   From these glands  four or five  absorbent vessels
 proceed, which accompany the great blood vessels of
 the lower extremity;  and,  proceeding with  them
 through the aperture in the tendon of the adductors,
 continue upwards until they enter some of the glands
 of the groin.
   The glands of the ham and groin, which are so in-
 timately connected with the absorbents of  the lower
 extremity, are very different from each other.
   The Popliteal Glands,  or those of the Ham, are
 but three or four in number, and very small in size.
 They are generally deep-seated, and very near the
 artery.
   The Inguinal Glands vary in number, from  eight
 to twelve or more.  They are superficial and deep-
 seated.    The superficial communicate principally
 with the superficial absorbents.  The lowermost of
 them are at some distance  below Poupart's ligament,
 and the uppermost  are  rather  above it.   They are
 exterior to the fascia of the thigh.   Their number is
 generally six  or eight, while that of the deep-seated
is but three or four.
  The superficial absorbents from  below, approach
very near to each other, and enter these glands.—
They are commonly distributed  among three or four
of the lowermost;  but some of  them  pass  by these,
and proceed  to one that is higher up; and  some-
times  there are absorbent  vessels which  pass to the
abdomen without entering  into any of the glands of
the groin.
  The deep-seated  absorbents  pass into  the  deep-
seated glands, which, as has been  already observed,
are but few, and lie very near the artery under the
fascia  of  the thigh.  The two sets  of glands are
connected  to  each  other by many absorbent vessels
that pass  between them.  The  vessels which finally
go out of these glands are considerably less in num- 
       Inguinal and External Iliac Glands.   379

ber than those which enter into them.   They pro-
ceed under Poupart's  ligament, and,  in some in-
stances, a large  proportion of them passes through
three glands which lie below this ligament, and are
often so arranged,  that they lie on  each side of the
great femoral vessels, and  above them.  One  very
frequently is found on the inside of the femoral vein,
in the vacuity between it and the internal part of the
ligament.    All  the absorbents of the, lower extre-
mity,  however,  do  not enter these glands.   Some
pass along the great vessels and enter  other glands
near the margin of the pelvis.   Some also descend a
short distance into the pelvis, and unite with vessels
that are passing from the pelvis to the plexus and the
glands that surround the external iliac.
   The absorbents  which  proceed  from the glands
last mentioned,  joined to those  which pass under
Poupart's ligament, without entering these glands,
and some which  come from the pelvis,  form a  large
plexus, which almost surrounds the external iliac ves-
sels, and contains many glands.
   These External Iliac Glands vary in their number
from  six to ten or twelve.   They lie on the side of
the pelvis, in the course of the  external  iliac vessels,
and some of them  are of considerable size.  These
glands and the  plexus of  absorbents, extend in the
track of the iliac vessels, to the  first lumbar vertebra.
In this course they are joined  by the plexus which
comes from the pelvis; and soon after they arrive at
the Lumbar Glands, which form a  very large assem-
blage, that extends from the bifurcation of the  aorta
to the crura of the diaphragm.
   These glands lie irregularly,  on  the  aorta, the
vena cava, and the lumbar vertebrae.  Most if not all
the absorbents above mentioned pass through some of
them; and from the union of these absorbents, some 
380      Absorbents of the Testicles, $c.

of the great branches, which unite to form the tho-
racic duct, are derived.
  In this course from the thigh to the lumbar glands,
these  absorbent vessels are joined by several others.
The Superficial Absorbents of the scrotum commonly
enter into the upper inguinal glands, and thus unite
to the great body of absorbents.
  The Absorbents of the Testicles, originate in the
body, and the coats of the  testicle, and in  the epi-
didymis, and are  remarkably large and numerous.—
They proceed along the spermatic cord, through the  %
abdominal ring, to the lumbar glands.   These ves-
sels are remarkable for the little communication they
have  with each  other.
  The  Deep-seated Absorbents of the Scrotum ac-
company the absorbents of  the testicle to the lumbar
glands; but those which are superficial enter the up-
per inguinal glands.
  The Absorbents of the Penis are also deep-seated
and  superficial.   The deep-seated  arise  from the
body  of the penis, and accompany the internal pudic
artery into  the pelvis.   The superficial absorbents
arise  from the prepuce,  and  pass along the dorsum
of the penis.   There are frequently several trunks
which  receive  branches from the lower surface of
the penis in their course.   At the root of the  penis
they generally separate to the right and left, and pass
to the glands on the respective sides.
   In females,  the  absorbents of the interior  of the
clitoris  accompany the internal pudic artery.  Some,
which arise about the vagina, pass through  the abdo-
minal ring with the round ligament: and others pro-
ceed  to the inguinal glands. 
   Absorbents of the Pelvis and the Kidneys. 381

                    section ii.

 Of the Absorbents of the Abdomen and Thorax.

   The Absorbents of the lower portions of the pa-
rietes of the Abdomen  and the Pelvis  unite into
trunks that follow the epigastric, the circumflex and
the iliac, as well as the lumbar and sacral arteries,
&c.  They proceed  to some of the glands which are
in the groin ;  or  in the external iliac,  the hypogas-
tric, or some of the contiguous plexuses.
   The Absorbents of the Womb are extremely nu-
merous; and, in the gravid  state,  are very large.
Those which are  on the neck and anterior part of the
uterus,  join the  hypogastric plexus.  Those which
are on the posterior part of the  body, accompany
the spermatic vessels.
   The  Absorbents  of the Bladder pass to  small
glands on its lateral and inferior parts,  and finally
join the hypogastric plexus.
   The Absorbents of the Rectum are of considerable
size.   They pass though  glands that lie upon that
intestine, and unite with the lumbar plexus.
   The Absorbents of the Kidney are superficial and
deep-seated.  They are  very numerous,  but, in a
healthy state of the  parts, are discovered with diffi-
culty.   Cruikshank describes them as they appeared,
filled with blood, in consequence of pressing upon
the kidney when its veins were full of blood.  Mas-
cagni did not inject  the superficial vessels with mer-
cury ;  but describes them as they appeared  when
filhed with colourless size, after he had injected the
blood vessels of the organ with the coloured fluid.—
The deep-seated  absorbents pass out of the fissure
of the kidney with the blood vessels, and unite with
the superficial;  they proceed to the lumbar plexus,
 and pass into different glands. 
382 Lacteals, or absorbents of the Intestines.

   Absorbent vessels can be proved to  proceed from
the pelvis of the kidney, and the ureters, by artifices
analogous to those above mentioned.
   The Glandulx Renales are also supplied with ab-
sorbents, which are numerous in proportion  to the
size of the organs.  They commonly  join  those of
the kidney.

         The Absorbents of the Intestines

Have generally been called  LACTEALS, from the
white  colour of the chyle which  they contain : but
there seems no reason for believing that they are dif-
ferent in their structure and nature from  the absorb-
ents in other parts of the body.   A small number of
them  appear  as if  they formed a part of the  struc-
ture of the intestines,  and originated from their ex-
ternal surface, as they  do in other parts of the abdo-
men ; while the  principal part of them are appro-
priated to the absorption of the contents of the  cavity
of the intestines.
   The first mentioned absorbents  run between the
muscular and peritoneal coats, and proceed for some
distance lengthways on the intestine, while the  others
proceed for some distance within  the  muscular coat,
with the arteries ; and  after  passing through it, con-
tinue between the lamina of the mesentery.
   Branches of these different absorbents are frequent-
ly united in one trunk  so as to prove that there is no
essential difference between  them.
   The absorbents which come from the internal sur-
face of the intestines commence  in the  villi.   The
manner in which they  originate has been the subject
of considerable inquiry, as has been stated in the ac-
count of  the intestines.*
   The lacteals or absorbents of the  intestines are
* See page 105. 
     Lacteals, or Absorbents of the Intestines. 383

very numerous.   They pass between  the lamina of
the mesentery to glands which are also seated be-
tween those lamina.   The number of these glands is
very considerable,*  and they  are various in size—
some being very minute, and others eight or ten lines
in diameter.   They are  generally placed at a small
distance from each other, and  are most numerous in
that part of the  mesentery which is nearest to the
spine.  They are almost always at some distance from
the intestines.  They appear to be precisely like the
absorbent glands in other places.
   These absorbent vessels, in their course frequently
divide into branches; which sometimes go to the same
gland,  sometimes to  different glands, and sometimes
unite with other absorbent  vessels. As they proceed,
they frequently enlarge in size. When they have  ar-
rived near the spine, they frequently form three, or
four trunks, and sometimes one or two ; which  pro-
ceed in the course of the superior mesenteric artery,
until they have arrived near to the aorta.  Here they
either pass into the thoracic duct,  or descend and join
the trunks from  the  inferior extremities, to form the
thoracic duct.  The  absorbents of the great intestines
are not equal in  size to those of the small; but they
are numerous.   They enter into glands,  which are
very near, and  in some places, in  contact with the
intestine; and are  commonly  very small in  size.
The vessels which arise  from  the  caecum, and the
right portion, as well as the arch  of  the colon, unite
with those of the small intestines; while the vessels
from the left side of  the colon,  and the rectum, pro-
ceed to the lumbar glands.
   The absorbents of  the  intestines are frequently
injected with mercury; but the injection does not
proceed to their termination with so much facility as
* They have been estimated between 130 and 150, 
384        Absorbents of the Stomach.
it does in others vessels of the same kind.   They
have, however, very often been seen in animals, who
were killed for the purpose  after eating milk ; and
in several human subjects who died suddenly during
digestion.—The  description  of the  origin  of  the
lacteals, quoted in page 108,  from Mr.  Cruikshank,
was  taken from a subject of this kind,  of which an
account is given in his work on the absorbing ves-
sels, p. 59.
  It is worthy of note, that  in several instances,  in
which the lacteals were thus found  distended with
chyle, the glands in the mesentery were also uniform-
ly white.
          The Absorbents of the Stomach

Are of considerable  size,  and  form  three divisions.
Thje vessels of the first set appear upon both sides
of the  stomach,  and  pass  through a few glands on
the  small curvature  near the omentum minus.—
From these  glands  they proceed  to others, which
are larger, and which also receive some  of the deep-
seated  absorbents of  the  liver.  The  vessels  from
these glands pass to the thoracic duct, near the ori-
gin of the coeliac artery.  The second arise  also on
both sides of  the stomach, and pass to the left extre-
mity of the great curvature to  unite  with the absor-
bents of that side of the great omentum. They then
proceed with the lymphatics  of the spleen  and pan-
creas, to  the  thoracic  duct.   The last  set,  pass  off
from the  right extremity of the great curvature, and
unite also with absorbents from the right portion of
the omentum.  They proceed near the  pylorus, and
go  to the thoracic duct, with some, of the deep-
seated absorbents of the liver.
  Although the absorbents of the stomach are deep-
seated, as well as superficial, it is a general senti-
ment, that they do not contain  chyle in the humau 
Absorbents of the Liver.
38j
subject; notwithstanding chyle has been found in the
absorbents on the stomach of dogs, and  some  other
animals.  It ought, however to be remembered, that
Sabatier has, in some instances, seen white lines on
the stomach, which he supposed to be lacteals.

           The Absorbents of the Liver
Are especially interesting, because they have  been
more completely injected than those of any other
viscus.  They are deep-seated and superficial.  The
superficial it has been already observed admit of in-
jection in a retrograde direction, and, therefore, can
be exhibited most minutely ramified. _They commu-
nicate freely with each other, and also with the deep-
seated vessels, by their small ramifications ; so that
the whole gland has been injected  from one  large
vessel.
   The gland is so large,  that the absorbents of the
superior and inferior surfaces proceed from it in dif-
ferent directions.
   A large  absorbent is generally found on  the sus-
pensory ligament.  This is  formed by the union of
a great many branches that  arise  both  on the right
and left lobes,"but principally on the right.  It often
passes through the diaphragm at an  interstice which
is anterior to the xiphoid cartilage, and then proceeds
through glands on the anterior part of  the  pericar-
dium.
   Several absorbents proceed to the  lateral ligaments
on each side,  and then pass through the diaphragm.
Some of these branches return again into the  abdo-
men, and the others generally run  forwards  in the
course of the ribs, and join those which passed up
from the suspensory ligament. The truuk, or trunks,
formed by these vessels,  either pass up between the
lamina of the  mediastinum,  and terminate in the up-
   Vol. n.              49 
386   Absorbents of the Liver and Spleen.

per part of the thoracic  duct; or they accompany
the internal mammary arteries, and terminate on the
left side in the thoracic duct, and on the right in the
trunk of the absorbents of that side.
   The Absorbents on the concave side of the Liver
are as numerous as those on the convex side ;  they
are also very abundant on the surface  of  the gall
bladder.   The greatest part of them  join the deep-
seated vessels.
   The Deep-seated Absorbents proceed in consider-
able numbers from the interior of  the liver  through
the portae.  They accompany the billiary ducts and
the great  blood vessels of the organ;  and,  after
passing through several glands, near the vena porta-
rum, terminate in the thoracic duct,  near the  com-
mencement of the superior mesenteric artery.
   Mascagni states,  that the absorbents of the  liver
will be distended,  by injecting warm  water into the
biliary ducts, or the vena  portarum.
   He also observes, that in those preparations in which
the superficial vessels are completely injected, in the
retrograde direction, the peritoneal coat of the liver
appears to be composed entirely of absorbent vessels;
and to be  connected to the  membrane within,  by
many filaments which are also  absorbent vessels.

           The Absorbents of the Spleen

Are composed of superficial and deep-seated vessels;
but they differ greatly from those of the liver,  in
this respect, that the superficial vessels are  remark-
ably small in the human subject.
   Mascagni however asserts,  that when the blood
vessels of the spleen are injected with size,  colour-
ed with vermilion, these  absorbents  will be  filled
with colourless size.
   In the spleen of the calf the superficial absorbents
are remarkably large. 
           Absorbents of the Pancreas.        387

  In the human subject the superficial absorbents of
the spleen proceed from the convex to  the concave
surface, and there communicate with the deep-seated
absorbents, which proceed from the interior of the
organ with the blood vessels.
  These Deep-seated Absorbents are very numer-
ous, and also large.  They accompany the splenic
artery; and in their course pass through many glands,
some of which are said to be of a dark colour.  The
glands lie on the splenic artery, at a short distance
from each other.  The  absorbents of the spleen re-
ceive the absorbents of the pancreas in their course;
they unite with the absorbents of the  stomach and
the lower surface of the liver, and pass with them to
the thoracic duct.
  Little has  been latterly  said by practical anato-
mists respecting

         The Absorbents  of the Pancreas.

Mr. Cruikshank once injected them in the retrograde
direction ;  he found that they came out of the lobes
of the pancreas in short branches like the blood ves-
sels, and passed at right  angles into the absorbents
of the spleen, as they accompanied the artery in the
groove of the pancreas.

          THE THORACIC  DUCT,*

Or  common trunk of the absorbent system, is formed
by  the  union of those  absorbent vessels  which are
collected on the lumbar vertebras.
  These vessels,  as it has  been  already observed,
are derived from various sources, viz.
  The Lower  Extremities; the lower part of the
Trunk of the Body; the Organs of Generation; the

  * First discovered by Eustachius in the horse, 1564, but he considers it
a vein for the nourishment of the thoracic viscera.—Ep. 
388    Commencement of the Thoracic Duct.

Intestines,  with the other Viscera of  the  abdomen
and Pelvis, except a part of the liver.   Their num-
ber is proportioned to the extent of their origin:  for,
with the numerous glands appropriated to them, they
form the largest absorbent  plexus in  the body,  and
are spread over a considerable  portion of  the aorta
and the vena cava.
  The manner in which  these vessels unite to form
the thoracic duct, is very different in  different sub-
jects; but in  a majority of cases it  originates imme-
diately  from  three  vessels,  two  of which are  the
trunks of the absorbents of  the lower extremities,
and the other is the common trunk of the lacteals  and
the other absorbents of the intestines.
  These vessels  generally unite on  the second or
third lumbar vertebrae;  and, in some instances, the
trunk which they form dilates considerably, soon af-
ter its  commencement; in  consequence of which  it
was formerly called the  RECEPTACLE of  the
CHYLE.   At first it lies* behind  the aorta, but  it
soon inclines  to the  right of it, so as to be behind the
right crus of  the diaphragm.   In the thorax, it  ap-
pears on the  front of the spine, between the aorta
and the  vena azygos,  and continues  between these
vessels until it has arrived at  the fourth or third dor-
sal vertebra.  It then  inclines to the left, and pro-
ceeds in that direction  until it emerges  from  the
thorax, and has arisen  above  the left pleura, when
it continues to  ascend  behind the  internal jugular,
nearly as high as the sixth cervical vertebrae: it then
turns downward and forward, and, after  descend-
ing from six to ten  lines, terminates in the  back part
of the angle formed by the union of the left internal
jugular with  the  left subclavian  vein.   Sometimes,
after rising out of  the thorax,  it  divides into  two
branches, which unite before they terminate.  Some-
times it divides, and one of the  branches terminates 
            Absorbents of the Lungs.         389

at the above mentioned angle, and  the other in the
subclavian vein, to the left of it.
  The orifice of the thoracic duct has  two valves,
which effectually prevent the passage of blood  into
it from the vena cava.
  There are sometimes slight flexures in the course
of the duct; but it generally inclines to the left, in
the upper part of the  thorax, as above mentioned;
and is then so near the left lamen of the mediastinum
that if it be filled with coloured injection, it can be
seen through  that membrane, when the  left lung is
raised up and pressed to the right.
  The duct sometimes varies considerably in its dia-
meter in different parts of its course. About the mid-
dle of  the thorax it has often been found very small.
In these cases it generally enlarges in  its progress
upwards, and is often three lines in diameter,  in its
upper part.  Many anatomists  have  observed  it to
divide and to unite again, about the middle of the
thorax.
            Absorbents of the Lungs.

   The  absorbents of the lungs  are very numerous,
and, like those of other viscera, are superficial and
deep-seated.
   The large superficial vessels run in  the  interstices
between the lobuli, and therefore form angular figures
of considerable size.   In successful injections, the
vacancies within these figures are filled up with small
vessels, and the whole  surface  appears minutely in-
jected.
   Mascagni observes,  that the superficial vessels are
very  visible when any fluid has been  effused into
the cavity  of the thorax; or when warm water is in-
jected, either into the  blood vessels of the lungs,  or
the  ramifications of  the trachea.   Cruikshank de-
monstrated them by inflating the lungs of a still  born 
390         Absorbents of tile Lungs.
child;  in  which case  the  air passes rapidly into
them.
  The deep-seated  absorbents  accompany the blood
vessels and the ramifications of the bronchise.  They
pass to the dark coloured glands, which are  situa-
ted on the trachea at its  bifurcation;  and on those
portions of the bronchise which are exterior  to the
lungs.   The injection of the  absorbents, which pass
to and from these glands, seems to  prove that they
are of  the same nature with the absorbent glands in
general notwithstanding their colour.   They are nu-
merous, and they vary in  size;  from  a diameter of
two lines, to that of eight or ten.
  From these  glands, some of the absorbents of the
left lung pass into the thoracic duct,  while it  is in
the thorax, behind the bifurcation of the trachea;
others proceed upwards and enter into it near its ter-
mination ; while those of the right lung terminate in
the common trunk of the absorbents of the right side. 
CHAPTER II.
OF THE ABSORBENTS OF THE HEAD AND NECK ;  OF
  THE UPPER EXTREMITIES, AND THE UPPER PART
  OF THE TRUNK OF THE BODY.

  •The absorbents from the various parts of the head
pass through glands, which are situated on the neck,
or the  lower part of the head.  Those on the head
are the least numerous, and also the least in size.—
Some of them,  which are generally small, lie about
the parotid gland.   Several  of them, which are also
small,  are on the occiput,  below  and  behind the
mastoid process.  Sometimes there  are two or three
on the cheek, near the basis of the lower jaw, about
the anterior edge of the masseter muscle.  Below the
lower jaw,  in contact with  the sub-maxillary gland
and anterior to  it, there are always a number of these
glands, which are generally  small, but often  swelled
during infancy.
   The Glands  on the Neck are the most numerous.
Many  of them  are within the sterno-mastoid  muscle,
and accompany the internal jugular vein and the
carotid artery down to the first rib.  Many also lie
in the  triangular  space between the sterno-mastoid
muscle, the  trapezius, and the clavicle ;  therefore it
has been truly said  that the glands of the neck are
more numerous than those of any other part, except
the mesentery.   They are frequently called Glan-
dulx Concatenatx.   It has  already been mentioned
that the various absorbents, which are connected with
these glands, unite on each side into a trunk, which
on the left passes into the thoracic duct, and on the
right into the common trunk of the  absorbents  of
that side, 
392     Absorbents of the Head and Neck.

                    section %.

    Of the Absorbents of the Head and Neck.
  There is the greatest reason to  believe that the
brain and its appendages are supplied with  absorb-
ents like the other parts. Some of these vessels have
been discovered in the cavity of the cranium; but
very little precise information has as yet been obtain-
ed, respecting the extent, or arrangement of the ab-
sorbent system, in this part of the body.
  The absorbents on the exterior of the head are as
numerous as in other parts of the body.  On the oc-
ciput they pass down, inclining towards the ear, and
continue behind it to  the side of the  neck; behind
the ear they pass through several glands.—From the
middle or temporal region of the cranium, they pass
with the carotid artery before the ear, and enter some
small glands that lie on the parotid;  from which they
continue to the neck.
  They are on every part of the face, and unite, so
that their principal trunks, which are very numerous,
pass over the basis of the lower jaw,  near the facial
artery.   They enter into glands, which are also very
numerous, immediately under the jaw, or which are
sometimes to be found on the cheek, at the anterior
edge of the masseter muscle.  All  the absorbents of
the exterior part of the head  pass  to the glands  on
the side of  the neck, already described.
  Those from  the interior of the nose accompany the
ramifications of the internal maxillary artery, and
proceed to glands behind the angle of the lower jaw;
into which  glands also  enter  the absorbents of the
tongue and inner  parts of the mouth.
  The absorbents of the thyroid gland, on the left
side, pass down to the thoracic duct;  those on the
right, unite to the  trunk of the absorbents on that 
       Absorbents of the Hand and Arm.     393

side, near its termination.  It has been remarked that
they can be readily injected, by thrusting the pipe
into the substance of the gland.

                    section ii.

Of the Absorbents of the Arm and Upper Part of
                   the Trunk.

   The absorbents of the arm are superficial and deep-
seated, like those of the lower extremity.
   The superficial absorbents have been  injected on
the anterior and posterior surfaces of the fingers  and
the thumb, near their  sides.   On  the  back  of the
hand they are very numerous, and increase consi-
derably in their progress up the fore-arm.  As they
proceed upwards, they incline towards  the anterior
surface of the fore-arm'; so that by the time they have
arrived at the  elbow, almost all of them are  on  the
anterior surface.  The absorbents on the anterior part
of the hand are not so numerous as those on the back.
Sometimes there are digital branches from the  fin-
gers, and an arcus in the  palm;  but this bow is not
formed by one large absorbent, analogous to the ulnar
artery.  On the contrary, its two extremities are con-
tinued over the wrist, and pass on the fore-arm  like
 the absorbents.
   At the elbow, some of them often pass into one or
 two small glands,  which are very  superficial;  but
 the  whole of the absorbents, somewhat reduced in
 number, as some of them unite together, pass along
 with the blood vessels into the hollow of the arm-pit;
 where  they enter the axillary glands.  There are
 generally  one or more vessels which pass  in  the
 course of the cephalic vein, between the pectoral and
 the deltoid muscle, and enter into some of the glands
 under the clavicle.
   Vol. ii.             50 
394  Absorbents of the Upper Part of the Trunk.

  There are almost always several  glands in and
near the axilla.  Some of them are  very near the
great blood vessels; sometimes one or. more of them
are much lower;  sometimes they are to be found
under the pectoral muscle.   They are commonly not
so large as those of the groin,  and are surrounded
with fat.
   The deep-seated absorbents  originate also at the
fingers, and soon accompany the branches of the ar-
teries.  Those which attend the radial artery, origi-
nate on the back of the hand, and also in the palm,
where they are associated with  the arcus profundus.
They go up with the radial artery to the elbow, and
sometimes pass through a small gland about the mid-
 dle of the fore-arm.
   Those  which  attend the ulnar artery, commence
 under the aponeurosis palmaris, and go with the  ar-
 tery to the elbow;  at the bend  of the elbow they  are
 generally  joined by one or more, which accompany
 the interosseal artery; there they unite, so as to form
 several trunks which pass up to the axillary with  the
 humeral  artery.  They sometimes pass through  one
 or two glands, which are near  the elbow; and they
 receive in their  course, deep-seated branches from
 the muscles on the humerus.
   The absorbents from the  anterior  and external
 part of the thorax, and the upper part of  the abdo-
 men, also proceed to the axilla, and enter into  the
 glands there; those which are deep-seated, joining the
 deep-seated vessels.   The absorbents of the mammse
 pass to the same glands; and when they are affected
 with the virus of cancer, can often be perceived, in
 their course, in the living subject.
    The absorbents of the uppermost half of the back,
 and those of the back of the neck, go likewise to the
 axilla.
    The absorbent vessels, collected from these vari- 
      Facts relating to Cutaneous Absorption.   395

ous sources, proceed from the  exterior to the inner-
most glands,  but with  a considerable diminution of
their number;- they  accompany the  subclavian  vein,
and  are reduced to  one  or two  trunks,  that gene-
rally unite before their termination.   On  the left
side, the absorbents  of the head  and neck generally
open into the thoracic duct, as has been already ob-
served ;  and those of the left arm also open into the
thoracic duct, or into the subclavian vein  very near
it.   On  the right side  the absorbents from each of
these  parts empty into  the common  trunk; which
often is  formed by the  union of  large vessels,  from
four sources;  viz. the Head, the Thyroid gland, the
right arm,  and the right cavity of the Thorax, &c.
The diameter of the trunk is very considerable; but
it is often not more than half an  inch  in length.   It
generally opens  into the  right  subclavian  vein, at
the  place where  it  unites  to the right internal ju-
gular.

     Two respectable physiologists of Europe, (M. Seguin, of
       Paris, and the late Dr. Currie, of  Liverpool,) have
       doubted  whether absorption  takes place on the  exter-
       nal surface of the skin.* This question has been ex-
       amined in a very interesting manner by several  gra-
       duates of the  University of Pennsylvania, who chose
       it for the subject of their inaugural theses ; viz. Drs.
       Rousseau, Klapp, Daingerfield, Mussey, and J. Brad-
       ner Stewart.                                   . .
     The three first of these gentlemen state, that when spirit
       of turpentine, and several other substances  which are
       commonly supposed to be absorbed by the skin, were
       applied to it in a way which prevented their volatile

  * I believe that M. Seguin's Memoir on this subject was read to the
 Academv of Sciences a short time before the meetings of that body were
 suspeS   It was published byM. Fourcroy, in La Medicine Eclairee
 car lesScences Physiques, vol. iii.  An extract from M. Fourcroy's pub-
 ficatXn may b?«2ta U» Mth chapter of the first volume of Dr.  Currie's
 « Medical Reports on the Effects of Water," &c. in which is also con-
 tained a statement of the Doctor's «wn experiments and reflections. 
396 Experiments of K. Boerhaave and J. Hunter.

       parts from entering  the  lungs  by respiration, no ab-
       sorption took place.   But when they inspired air im-
       pregnated with exhalations from these substances, they
       perceived satisfactory proofs that  the exhalations en-
       tered the  system.  From these  facts they inferred that
       when those articles  entered the body by absorption,
       they were taken in by the lungs, and not by the exter-
      nal surface.
     On the other hand, the two  gentlemen last  mentioned,
       state that after immersing themselves  in  a bath con-
       sisting of a decoction of rhubarb, of madder, or of tur-
       meric, their urine  became  tinged  with   these sub-
       stances.   They also assert that the colouring matter
       of these different articles is not volatile ;  and, there-
       fore, could not have entered the lungs during the  ex-
       periments.*
     The statement in page 374, from Dr. Soemmering, that
       when mercury is injected backwards in the absorbent
       vessels which originate on the  foot, it will sometimes
       appear in small globules  on  the skin of the foot,  has
       an important connexion with this subject.!
    About the middle of the last century, it was generally
      believed by anatomists, that absorption was performed
      by the veins.   This doctrine seemed to be established
      by the experiments of Kaaw Boerhaave, which are re-
      lated, with many other interesting statements, in his
      work, entitled u Perspiratio  Dicta Hippocrati," &c.
      published at Ley den, in 1738.   In these experiments
      it appeared to the author, that when the stomach of a
      dog was emptied of its contents, and filled with warm
      water, immediately after death, the water passed into
      the minute ramifications of the veins of  the stomach,


  * The TheBis of Dr. Rousseau was published in 1800.  Those of Dre.
Klapp and Daingerfield in 1805.  Dr. Mussey published  in the Third
Supplement to the Medical and Physical Journal of Dr. Barton, in 1809.
Dr. Stewart published in  1810.  Additional observations  by Drs.  Klapp,
Rousseau and Smith, are published in the Philadelphia Medical Museum,
vol. i. new series.
  t Since the publication of the first volume,  the author has enjoyed the
advantage of consulting a translation, in manuscript, of some parts of the
German edition of Dr. Soemmering's valuable work on the  Structure of
the Human Body. 
Experiments of Magendie and Delile.   397
      and from them to the vena portarum, and  ultimately
      to the heart, in large quantities.
   This account appears to be disproved by some  experi-
      ments of the late John Hunter,  made  about  twenty
      years after, and published in the Medical Commenta-
      ries of Dr.  William Hunter, Part I.----Mr. Hunter's
      experiments have been considered as establishing the
      fact, that absorption, (in the intestines at least,) is per-
      formed exclusively by the lacteals, or proper absorbent
      vessels, and  not at all by the veins.   Kaaw Boer-
      haave is of course supposed to have been  mistaken 5
      and Mascagni, who has repeated his  experiment, re-
      fers the appearance of water in the veins to transuda-
      tion through the coats of the intestines j which he has
      observed to take place to a great degree.
    In the year 1809, a memoir was presented to  the nation-
      al institute of France  by Messrs. Magendie and De-
      lile,  which contains an account of some experiments
      that  have an important relation to the above mentioned
      subject*—The authors being greatly surprised at the
      rapidity with which the poison of Java, &c. appeared
      to enter the  sanguiferous system, instituted  a series
      of experiments to determine whether these substances
      proceeded  to that system by the circuitous route of the
      absorbent vessels, or by the shorter course of the veins.
      Two of their experiments are especially interesting.
      They made an incision through the parietes of the ab-
      domen of a living dog, who had eaten a  large quantity
      of meat some hours before, (that his lacteals might be
      visible from  their distension with chyle,)  and, draw-
      ing out a portion of the  small intestine, they applied
      two ligatures to it, at the distance of five inches  from
      each other.   The  portion of intestine  between these
      ligatures was then separated by incision from the rest
      of the intestinal tube, and all the lacteals, blood ves-
      sels, &c. which passed to and from  it,  were divided,
      except one artery and a  vein.  A considerable length
      of this artery and vein were detached from  all the sur-
      rounding parts, so that  the  authors supposed these


  * The title  of the  paper is a " Memoir on the Organs  of Absorption
in Mammiferous Animals." A translation of it was published in the Me-
dical and Philosophical Register of New York, and in several other perio-
dical works. 
398   Experiments of Magendie and Delile.

      vessels to form the only connexion between the por-
      tion of the intestine and  the rest of the body.  Into
      the  cavity of the  intestine, which was thus circum-
      stanced, they introduced a small quantity of the poison,
      and, to their astonishment, it produced its fatal effects
      in the same manner it would have done if it had been    .#
      introduced into the intestine while  all its connexions
      with  the  body were entire.   This  experiment, they
      assert, was  repeated  several times,  without any dif-
      ference in the result.
    After several other experiments, they finally  separated
      the thigh  from the body of a living dog in such a man-
      ner that the  crural artery and vein were left undivi-
      ded.   A quill  was then introduced into the artery,
      and two ligatures were applied  to fix it round the
      quill.  The artery was  then divided between the two
      ligatures.  The vein was  managed  in the same man-
      ner.   There was, therefore,  no communication be-
      tween the limb and the  body,  except by  the blood
      which passed  through  the divided  vessels and the
      quills.  The poison was  then introduced under the
      skin of the foot, and soon occasioned the death of the
      animal: its deleterious effects commencing about four
      minutes after its application to the foot.  This expe-
      riment appears to prove decidedly that the blood is the
      vehicle" by which poison, when applied to the extremi-
      ties, is carried to  the body ;  although it may not de-
      termine the question whether this  poison was taken
      up by the absorbents or by the veins.*
    Some  other experiments  made  by the authors gave re-
      sults, which are very difficult indeed to explain. They
      wished to know if the blood of an  animal  thus con-
      taminated, would produce similar effects upon another
      animal; and, with  a view to ascertain this point, they
      insinuated a  small piece  of wood,  covered with the
      poison, into the thick part of the left side of the nose
      of a dog.  Three minutes  after the introduction of the
      poison, they transfused  blood from the jugular vein of
      the same side,  into one of the veins  of another dog.
      About one  minute after  the commencement of the
  * This experiment has been repeated  in Philadelphia. See Professor
Chapman's Medical and Physical Journal for February, 1823, No. 10.
Er>. 
 Report of the Committee of the Institutes.  399

     transfusion, the effects of the poison began in the dog
     to which it was applied, and continued until his death.
     Transfusion into the veins of the other dog went on
     during the whole time,  and he received a large quan-
     tity of blood from  the dying dog, without producing
     any effect.—They varied this experiment in the fol-
     lowing manner.  The thigh of a dog was separated
     from the body; the  artery and the vein were arranged
     as in the  former experiment;  and poison was intro-
     duced into the foot.  Three minutes after the intro-
     duction of the porson, the blood of the crural vein was
     passed  into  the  jugular vein of another  animal, and
     transfusion was continued  five minutes without pro-
     ducing any effect upon the animal receiving the blood;
     it was then stopped,  and the crural vein was so ar-
     ranged that the blood flowed from it into the animal
     to  which it belonged.  This animal very soon exhibit-
      ed symptoms of  the  operation of the poison.*
    From these very interesting experiments the authors in-
      fer that   "foreign  matters  do  not  always proceed
      through  the Lymphatic or Absorbent Vessels, when
      they enter into the  Sanguiferous system."
    This memoir was referred by the  Institute to four of its
      members, who are particularly distinguished by their
      profound  knowledge  of  anatomy  and  physiology.
      These  gentlemen,  after stating their belief that the
      functions of the lymphatic or absorbent system have
      been completely ascertained by the experiments and
      observations of  Hunter, Cruikshank,  Mascagni, &c.
      say further, that, in their opinion, the above mention-
      ed inference  ought  to be a little  modified, and  that
      facts are  not sufficiently numerous,  or  applicable to
      the point in question, to justify the inference  that
     foreign matters do  not always proceed  through  the
      Lymphatic or Absorbent Vessels,  when they enter the
      Sanguiferous system.   But they also add, that, as the
      author is  still engaged in a series of experiments  on
      the subject, they will suspend their judgment respect-
      ing the inferences to be deduced from  the  present
      statement.

  * An account of these experiments was published by M. Magendie in a
pamphlet.  A statement of  them is also  contained in the  report made to
the Institute by the committee to whom'the memoir was referred, which is
published in the Journal de Physique, for March 1813. In that statement
this last mentioned experiment is omitted. 
400           Of the Absorbent System.

    The most extensive  account of the absorbent system is
       contained in the  " Historia et Ichnographia Vasorum
       Lymphaticorum Corporis Humani" of  Mascagni.—
       " The Anatomy of the Absorbing Vessels of the Human
       Body,  by W. Cruikshank;"—and " The Description
       of the  Lymphatic System,  by Win. Hewson,"  (the
       second volume of his Experimental Inquiries,)--are
       also very interesting publications.


  A most interesting series of inquiries and experiments  in regard to the
laws of absorption will be found in Professor Chapman's Journal of tha
Medical and Physical Sciences, No. 6, in a report of a Committee of the
Academy of Medicine, signed by Doctors Lawrance and Coates, of this
city.—And a continuation of the same will be found in No. 10, of the same
Journal, signed by Doctors Lawrance and Coates. Since the publication
of the latter, to the regret of  all who knew him, and  to the great loss of
Anatomy and of Physiology, the indefatigable and excellent  Lawrahce
is no more.—Ed.
/ 
APPENDIX.
                 OP THE BLOOD.

  THE blood of a healthy person indicates a  ten-
dency to coagulate very soon after it is discharged
from the vessels which naturally contain it, although
it is perfectly fluid in those vessels.
  If it  remain at rest, after it  is drawn from the
vessels, it soon coagulates, into a solid mass, of a soft
texture.  From  this solid mass  a  fluid is soon ob-
served to  issue, which  first appears in very  small
drops on almost every part of the surface.  These
drops quickly increase and  run  together, and  in a
short time the fluid surrounds the solid mass, and ex-
ceeds it in quantity.
  The  solid  part  which thus  appears upon the
spontaneous separation of the blood,  is denominated
Crassamentum or Cruror: the fluid part is  called
Serum.
  The substance which contains the red colour of the
blood remains with the Crassamentum.  The Serum,
when it separates without agitation, is free from the
red colour.
  The colouring matter may be separated completely
from the Crassamentum by washing  it with water.
  The blood, therefore, consists of three parts, viz.
the Serum ; the Substance  which coagulates spon-
taneously ; and the Colouring Matter.
  Vol. ii.              51 
402        Appendix.—Of the Blood.


                    THE SERUM

Has a considerable degree of consistence, although
it is much thinner than blood.  In its perfectly na-
tural state, it is almost transparent, and appears to
be very lightly tinged with a greenish yellow colour;
but  it is  very ofteh impregnated with a portion of
bile, which  is probably carried to the blood vessels
by the absorbents.  It contains  a  large quantity of
albumen,  or  matter like the white of an egg.  If
heated to 140° of Fahrenheit, it  becomes opaque;
and when the heat is increased to 156 or 160,  it is
firmly coagulated.  It is also coagulated by  alcohol,
by mineral acids, and by rennet.*  It is proved by
chemists,  that it contains a small  quantity  of  pure
soda.  It therefore changes several of the blue co-
lours of vegetables green.   It is also found  to  con-
tain a similar quantity of the muriate and the phos-
phate of soda, and the phosphate of lime.   These
saline substances were discovered  by diluting serum
with water, and  exposing the mixture to  heat, by
which  the  albumen was  coagulated  into flocculi:
these flocculi were separated by filtration :  the li-
quor was then diminished  by evaporation, and the
salts obtained from it by crystallization.
   Serum likewise contains a portion of sulphur  com-
bined with ammonia.
   When it is exposed to a coagulating  heat, a small
portion of it remains fluid.
   This fluid portion has been supposed to contain a
considerable quantity of gelatine ;  but it is contend-
ed by Mr. Brande,f that Gelatine does not  exist in

  * See Hewson, Vol. I. p. 139.—I suspect that some particular manage-
ment is necessary in the use of rennet.
  f In his Researches on the Blood communicated to the Royal Society
of London, in 1812, and republished iu the Eclectic Repertory, fer April, 
Appendix.—Of the Blood.         403
the serum of the blood, and that this portion consists
of albumen combined with a proportion of alkali.
  It is also asserted by Dr. Bostock,* one  of the
latest writers on the  subject, that the serosity of the
blood, (the term applied to the last mentioned fluid,)
contains no gelatine ; but that, with a minute quan-
tity of albumen, it Consists of a large portion of an
animal matter,  which is different either from gela-
tine or albumen, being unlike  either of them in its
chemical qualities.

                THE  CRASSAMENTUM

Is rendered very different in its appearance,  by the
different circumstances in which it may coagulate.
   When the blood remains at rest immediately after
it is drawn, the crassamentum which forms in it is a
concrete substance, without the smallest appearance
of  fibre in  its composition.  If the blood is stirred
with a rough stick, while  it is flowing from an ani-
mal,  a large  portion of it will  concrete  upon the
stick in a fibrous form, so as  to resemble a mass of
entangled thread, some of the red colouring matter
still adhering to it.
   The crassamentum, in  either of these forms, may
be washed perfectly  white ; the red colouring matter
 passing completely  away with the water.   In this
 state it appears! to  have  all the chemical  properties
 of the fibrous matter of muscular flesh.  It  also resem-
 bles the gluten of vegetables,  being soft and elastic.
 The name fibrin is now generally applied to it.
    If fibrin is washed and dried,  its weight is very
 small indeed when compared with that of the blood

  * See his observations on the Serum of the Blood, in the Medico-Chi-
 rurgical Transactions, Vol. II. republished in the Eclectic Repertory, for
 October 1812.                         *  . ,   ,.  .  T ,
  t By the experiments of Mr. Charles Hatchett, published in the London
 Philosophical Transactions for 1H00- 
404        Appendix.—Of the Blood.

from which it  has been obtained.  It is, therefore,
probable that a considerable  proportion of the bulk
of the crassamentum, as it forms spontaneously,  de-
pends upon the serum which exists in it, and can be
washed away.
   The spontaneous coagulation of the blood, which
appears to depend principally upon the Fibrin, may
be prevented by the addition of several foreign sub-
stances to the blood, when it is drawn.  It is subject
to great variations that depend upon the state of the
body at the  time of bleeding;  and in some condi-
tions, it does not take place at all.*
   In a majority of dead subjects the blood is fbund
more  or  less  coagulated  in the veins; but in some
subjects it is found without coagulation.  It is assert-
ed that it does not coagulate  in subjects who have
died suddenly, in consequence of anger,  lightning,
or a blow on the stomach.
             THE COLOURING MATTER.


   When the blood vessels in the transparent parts of
certain living animals are examined with magnifying
glasses, it appears that  the  red  colour of the blood
is owing to bodies of a globular form, which are dif-
fused through a transparent fluid.   The appearance
of these bodies has been examined, with great atten-
tion, by many physiologists,  since the  publication of
Leuwenhoeck, in the London Philosophical  Trans-
actions.!

  * See  an Inquiry into the Properties of the Blood, by the late Wm.
Hewson: and  Experiments by his son, T. T. Hewson, in the Eclectic
Repertory, Jan. 1811.—See also a Treatise on the Blood, &c. by the late
J. Hunter.
  t Among the most distinguished of these observers were Father de la
Torre, Haller, Hewson, Fontana, Spalanzani, J. Hunter, Cavallo.
  Some  short  accounts of Leuwenhoeck's original observations on the
blood are to be found in the Philosophical Transactions of London, for 
             Appendix.—Of the Blood.         405

   Several of these gentlemen have described the ap-
pearance of the blood very differently ; but Haller,
Spalanzani and  J. Hunter  agree that the figure of
the  red  particles  is  globular.*  Hunter  observes
further, that the red globules  do not run into  each
other as two globules of oil would  do when  divided
by water ; and he believes that they cannot unite.—
At the same time they seem not to have the proper-
ties  of  a solid :  for when circulating in  the vessels,
they assume elliptical forms, adapting themselves to
the size of the vessels.   They also  excite no sensa-
tion  of solidity when touched.
   They appear to  be  more  heavy than the other
parts of the crassamentum:  for  in healthy blood the
lower part of the mass  contains  more of the colour-
ing  matter then the upper part; and in the blood of
persons who labour under acute local  inflammation,
they often subside completely from  the upper part;
and  thus occasion what is called by Mr. Hewson, the
inflammatory crust, or size.
   It has  been observed  by Mr.  Hewson,  and  also
by Mr. Hunter, that the globules do not retain their
form in every fluid.   They are  said to be dissolved
1664, in the fasciculi which are numbered 102 and 106. A more full de-
scription is contained in Boerhaave's Academical Lectures on the Theory
of Physic. See the section on the nature of the blood.
  The glasses of Father de la Torre were transmitted from  Naples to the
Royal Society of London in 1765. They were accompanied by a letter
from Sir F. H. E. Stiles,  to which are subjoined some observations by the
Rev. Father himself.  The letter and the observations are published in the
55th volume of the Transactions of that society.
  In the year 1798, Tiberius Cavallo published an Essay on the Medicinal
Properties of Factitious Air, with an Appendix on the Nature of the
Blood, in which is contained a further  account of the glasses of de la
Torre.
  * I believe  that this is also the opinion of Fontana.—In J. Hunter's
work on the Blood there are some  interesting observations on micro-
scopical deceptions. See the note, commencing in page 39, Bradford's
edition. 
406       Appendix.—Of the Blood.

very quickly in water, and then they form a  fine
clear  red.   Several of the neutral  salts, when  dis-
solved in water, prevent the solution of the globules.
Mr. Hunter informs us, that the vitriolic acid, when
greatly diluted, does not dissolve them, &c.   The
muriatic acid, when three times as strong as vinegar,
destroys  their  colour without  dissolving them, al-
though when more  diluted, it dissolves them.
  The colour of the blood has, for a long time, been
supposed to depend upon Iron.  About the middle
of the last century, Vicentius Menghini published
in the Transactions of the Academy of Sciences of
Bologna, an  account of  experiments which  contri-
buted  to establish  this sentiment.   In  this account
he stated, that, after washing the colouring matter
from the crassamentum, he had separated it from the
water by boiling; in which case it either rose to the
surface of the water, or subsided, and left the water
clear.  After drying, with  a gentle heat, some of
the colouring matter thus separated, and then re-
peatedly washing it, he found that it contained a
considerable quantity of iron,which was attracted by
the magnet.
  After exposing a large quantity of the colouring
matter to an intense heat,  he found  in it a small
piece of iron, of a spherical form, but hollow;  and
a powder which was attracted by the magnet, but ap-
peared more like rust of  iron than iron filings.
  He believes the seat of this iron to be in the co-
louring matter of the blood, as neither the serum nor
fibrine appeared to  contain it.   According to his cal-
culation, the blood  of a  healthy man contains more
than two ounces of  iron.
  This doctrine of Menghini has been  very gene-
rally admitted; and several chemists of  the first
character, viz.  Bucquet, Fourcroy, Vauquelin,  &c. 
            Appendix.—Of the Blood.        407

have made experiments to ascertain  the  substances
with which the iron in the blood is combined.
  But within a few years, doubts have been express-
ed on this subject by several physiologists, and espe-
cially by Dr. Wells, and Mr. Brande.
  The first of these gentlemen, in his  " Observations
and Experiments on the Colour of the Blood," pub-
lished in the London Philosophical Transactions for
1797, states three reasons  for rejecting the opinion
that the colour of the blood is derived from iron.
  1. The colour of blood is destroyed by a heat less
than that of boiling water; whereas no colour arising
from a metal is destroyed by  exposing its subject, iu
a close vessel, to such a heat.
  2. If the colour from a metal, in any substance, be
destroyed by any alkali, it may be restored by the
immediate addition of an acid;  and the like will
happen by the addition of a proper quantity of an al-
kali, if the colour has been destroyed  by an acid.—
The colour of blood, on the contrary, when once de-
stroyed, can never be brought back, either by an
acid or an alkali.
  3. If iron be the cause of the red colour of blood,
it must exist there in a saline state;  since the red
matter  is soluble in water.   The  substances, there-
fore, which detect  the smallest quantity of iron in
such a state, ought  likewise to demonstrate its pre-
sence in blood; but  upon adding Prussian alkali,
and an infusion of galls, to a  very  saturated solution
of the red matter, he could  not observe "in the form-
er case the slightest blue precipitate;  or in the latter
that the mixture had acquired the least blue or pur-
ple tint."
  Mr. Brande, in a paper  entitled " Chemical Re-
searches on  the  Blood," &c. communicated to the
Royal Society of London in  1812, relates many ex-
periments which were made on the colouring matter 
408   Appendix.'■"Structure of the Glands.

of that fluid, with acids, alkalies, astringents, &c. &e.
From these experiments, he also infers, that the co-
louring matter of the blood is perfectly independent
of iron.
  In support of this inference, he adds, that the Ar-
menian dyers, in the preparation of their finest and
most durable red colours,  use  blood  in  addition to
madder, in order to ensure the permanency of these
colours.   As the compounds of iron convert the co-
lour of madder to gray and black, the production of
a bright colour by the addition of blood to madder,
he regards as a proof, that  iron  is not the colouring
matter of  blood.
  Many estimates  have been  made of the quantity
of blood in the human body; but some of the best in-
formed physiologists have  regarded  them as  falla-
cious.
             STRUCTURE OF GLANDS.

  Any original structure  that discharges from the
blood vessels a fluid different from those which they
naturally contain, may be  considered as glandular.
The function or process by which such fluids are de-
rived from the blood vessels is called secretion.
  A structure of this kind seems to exist in very dif-
ferent situations: for it is distinctly circumscribed in
many of those bodies commonly denominated glands,
which are of a very precise form; and it is also dif-
fused on some very  extensive surfaces.  The gastric
liquor, a most important secretion, is probably dis-
charged from vessels which open, like exhalents, on
the internal surface  of the stomach; and not from any
circumscribed bodies, which are generally  denomi-
nated glands.
  The name of gland  is  theoretically applied to 
        Appendix.—Structure of Glands.     409

several bodies which  cannot be  proved to secrete
any fluid whatever ; and also to those bodies  con-
nected with the absorbent vessels, which are called
the Lymphatic Glands ; bat it is most commonly ap-
propriated  to those organs which discharge a fluid
different from the blood.
  The structure by which mucus is secreted in some
places, appears  to be  very simple.    Thus in the
Schneiderian membrane and the urethra, there are
small  ducts  from four to six  lines in  length,  and
equal  in diameter  to  a  bristle, which  appear to be
formed of the membrane on which they open.  From
these  ducts mucus issues  to  cover the surfaces  of
these  membranes.   In  many  instances there is no
substance resembling that of the circumscribed glan-
dular  bodies, connected with  these ducts; but the
secreted fluid seems to be discharged into the ducts
from the small vessels on their surfaces.   The ducts
of this nature in the urethra  are denominated  La-
eunx.
  In some other parts of the body, the  cavities into
which mucus is discharged  are somewhat different,
both in form and size, from those above mentioned,
and are called Follicles.   These cavities  are  sur-
rounded with more or less of  a  pulpy vascular  sub-
stance, which has been considered as glandular, and
essential to the  mucous secretion.
  The circumscribed bodies,  which are commonly
called glands, differ in their internal appearance and
texture, from the other  parts of animals.  The  sub-
stance of which they consist differs very much in the
different glands;  and thus renders the liver,  kid-
neys,  salivary  glands, mammae, &c. very  different
from each other.   Some glands, as the salivary, &c.
are composed of several series of lobuli that succes-
sively diminish.   The smallest of these are denomi-
nated Acini.    Each  of them  is connected by a
  Vol  it               53 
410     Appendix.—Structure of Glands.

small artery and vein, to the large blood vessels  of
the glands ;  and also sends a branch to join the ex-
cretory  duct.   These Acini are therefore connected
to each other, by the blood vessels  and excretory
duct of the gland, and also by the cellular membrane,
which covers them externally, and occasions them to
adhere  to each other where they are  in contact.   In
consequence of this structure, these glands have a
granulated appearance.
   The  liver, when  incised with a sharp instrument,
appears differently; but when broken into pieces, it
seems to consist of  small acini.   Some  other glands,
as the  Prostate, appear to be uniform in their tex-
ture, and have none of this granulated appearance.
   The  structure of glands has long been an interest-
ing object of anatomical inquiry, and was investiga-
ted with great assiduity by those eminent anatomists,
Malpighi and Ruysch.
   Malpighi, as was formerly observed, used ink and
other coloured fluids in his injections.   He was also
very skilful in  the use of microscopes, and took great
pains in macerating and preparing the subjects of  his
inquiries.   Ruysch, on the other hand, used a ce-
raceous injection, and  was most  eminently successful
in filling  very small vessels with it.   Malpighi be-
lieved that  there were follicles or cavities in glandu-
lar bodies, which existed between the extremities of
the arteries and the commencement of the excretory
ducts of those bodies,  and that  in these cavities the
secreted fluids underwent a change.—Ruysch con-
tended, that  the arteries of glands  were continued
into excretory ducts, without  the  intervention of
any cavity or follicle; that the small bodies, which
had been supposed to contain follicles orcripae, were
formed by convulsions of vessels, and that the change
 of the fluid, or the process of secretion, is produced
 by the minute ramifications of the artery. 
        Appendix.—Structure of Glands.     411

  A very interesting account of this  subject is con-
tained in  two celebrated letters,  which passed be-
tween Boerhaave and Ruysch in the year 1721, and
are published at the end of the fourth volume of the
works of Ruysch.
  The opinion of Ruysch has been  most  generally
adopted by anatomists, and  has derived support and
confirmation from  several anatomists  since his time.
The late Mr. Hewson declared his conviction  that
the small globular bodies which are scattered through
the kidneys, and  were supposed to  be follicles or
cript3B, are merely convoluted arteries.  He also as-
serted, that the acini which appeared in the mammae
as large as the  heads of pins, when   the excretory
ducts of that gland were injected with vermilion and
painters' size, proved to be the minute ramifications
of the excretory duct, which divided very suddenly
into branches so small, that they could not readily be
seen by the naked eye.*
  Notwithstanding these reasons for  supposing  that
the excretory ducts of glands  were derived simply
from the arteries of  those bodies, it is said  that the
late Dr. W. Hunter used  to declare  his belief,  that
there was a part in glands which was not injected, in
his preparations; and to say further, that he  believed
his preparations were  injected as minutely as those
of Ruysch.
  All of these opinions have been strenuously con-
troverted by the  Italian anatomist, Mascagni,  who
believes that the arteries  terminate  only in veins:
and of course that they neither form exhalent  ves-
sels, nor communicate with the excretory  ducts of
glands.   His idea of the structure of glands is  dif-
ferent from those either of Malpighi  or of  Ruysch.
* See Experimental Inquiries, vol. ii. p. 178. 
412     Appendix.—Structure of Glands.

He supposes that glands contain a  great  number of
minute cells;  that the arteries, veins, and absorbent
vessels are spread upon the surfaces of these  cells,
in great numbers, and very irregularly.   From these
cells very small  canals originate,  which  unite to
form the  small branches of the excretory ducts.—
According to his idea  the  secreted  fluid  is   dis-
charged  through pores or orifices of the  blood  ves-
sels,  into the cells, and proceeds from them through
the canals, into the branches of the excretory ducts.
Absorbent vessels, in great numbers, originate from
these cells.
   In his great work on the absorbent system, when
treating on the termination of arteries and the com-
mencement'of veins, (Part I.  Section 2.) he asserts,
that  if the  kidneys are successfully injected with
size, coloured with vermilion, and then laid open by
a section  with a razor, it will be found that the  size
without the colour has passed  into  cells, which  are
very numerous ;  that the arteries and  veins are ra-
ramified  most minutely on the surfaces of these cells,
and that the tubuli uriniferi, as well as the absorbent
vessels, originate from them.
   He supposes that a considerable portion of the fluid
thus passing off from the blood vessels, is commonly
taken up  by the absorbent vessels of the kidneys; for
in two cases in which he found  the absorbent vessels
obstructed, a diabetes  existed,  which he  considered
as the effect of the inactivity of the absorbents.   He
asserts, that in the liver, pancreas, mammse, and  also
in the salivary and lachrymal glands, the minute ar-
teries and veins are also distributed upon the surfaces
of cells;  and that very small canals arise from these
cells, and unite to form the small branches of the ex-
cretory ducts.
   This great  anatomist appears to have  been much 
          Appendix.—Structure of Glands.      413

occupied with  microscopical  observations, and  has
gone largely into the discussion of this subject.*

       It must,however, be acknowledged, that no information
         which has as yet been obtained respecting the struc-
         ture of glands, enables us to explain their  wonder-
         ful effect upon the fluids which pass through them.
         It remains yet to be ascertained why one structure
         forms saliva and another bile ; or why  so much ap-
         paratus should  be necessary  for  the  secretion of
         milk, when adiopose matter appears to  be produced
         by the mere membrane in  which it is contained.
       Dr. Berzelius, professor of Chemistry at Stockholm,
         in a late work on animal chemistry,  asserts,  that
         if all the  nerves going to a  secretory organ are di-
         vided,  secretion will cease,  notwithstanding the
         continued circulation of the blood.  From  this, he
         thinks, that secretions depend upon the influence of
         nerves, although he cannot explain their effects.
       Mr. Home,  after relating  some  experiments upon
         blood and  serum,  made with  the  Voltaic Battery,
         proposes the following questions,  among others:—
         Whether a weaker power of electricity than  any
         which can be  kept up by art, may be capable of se-
         parating from the blood the different parts of which
         it is composed ; and forming  new combinations of
         the parts so separated ?—Whether the structure of
         the nerves may enable  them to possess a low elec-
         trical power, which can be employed for that  pur-
         pose ? &c.
              See the London Philosophical Transactions, for
                 1809, Part II.t

  * The late Dr. W. Hunter, in his Medical Commentaries, (p. 40,) avowed
 his belief, that  the fluids, which appear occasionally in the various  cavi-
 ties of the body, transude through the coats of the blood vessels.  Mr.
 Hewson,  (Experimental Inquiries, Vol. II. ChapT 7.) suggested several
 reasons for dissenting from this opinion; but Mascagni has endeavoured to
 support it.__See a long note to the above mentioned section of his work,
 page 74.
  t Mr. Wollaston has also published a small paper on this subject in the
 Philosophical Magazine, Vol. 33. 
 
                 GLOSSARY,*


EXHIBITING THE DERIVATION OF CERTAIN ANATOMICAL
                        TERMS.
                          A.

ACETABULUM. The cavity which receives the  head of
  the thigh-bone ; from acetum  vinegar :  so called, because
  it represents the acetabulum or saucer of the ancients, in
  which vinegar was held.for the use of the table.
Acini. From acinus a grape.
Acromion. A process of the scapula; from <**p«s extremity,
  and «jt«>5 the shoulder.
Anastomosis. The  communication of vessels  with  one ano-
  ther ; from «m through, and rop* mouth.
Anatomy. The dissection of the human body 5 from am, and
  re/uva to dissect.
Anconeus. A muscle ; so called from «yx»v the elbow.
Aorta.  Aeprj} from ; «*?§■ air, and rqgea to keep.
Aponeurosis.  A tendinous expansion ; from ««■«, and nvpov a
  nerve; from an erroneous supposition of the ancients, that
  it  was formed by an expansion of nerve.
Apophysis.  A process of a bone; from  ttirtQva to proceed
  from.  A synonyme of process.
Arachnoides. A net-like membrane; from «^«^vj» a spider,
  and *<&s likeness.
Artery. From *wf air, and r^ea to keep; because the ancients
  supposed that air only  was contained in them.
Arthrodia. A species of  connexion of bones; from upSpoa to
  articulate.
Arytaenoides. The name of two cartilages of the larynx; also
  applied to some muscles of the larynx j from ufvr*im a
  funnel, and eifos a shape.
* By Dr. Hooper. 
416                    Glossary.
Astragalus. A bone of the tarsus ; so called from its resem-
  blance  to a die used  in ancient games, from otrpctyxXos a
  cockal or die.
Atlas. The first vertebra of the neck ; so  called, because it
  sustains the head: from the fable of Atlas being supposed
  to have supported the  world;  or from ecrxxa to sustain, be-
  cause it sustains the head.
Azygos. A term applied to  parts without a fellow, from «
  priv. and £&y«s a yoke, because it has no fellow.

                            B.

Bursa. A bag j  from fivproi:  generally applied to the  bursse
  mucosae.
                            C.

Cancelli. Lattice work ; generally applied  to  the reticular
  substance in bones.
Cardia. The  superior  opening of the  stomach j  from  x.xphx
  the heart.
Carotid.  The name of  some  arteries of the neck and  head
  from xccpou to cause to sleep;  for, if tied with a ligature,
  the animal was said  to be affected with coma.
Carpus. Ketpnes ', the wrist.
Clavicula.  The clavicle or collar-bone, a diminutive of clavis
  a key; so called from its resemblance to an ancient key.
Clinoid. Four  processes  of the sella turcica of the ethmoid
  bone are so called,  from *A<v»  a bed, and afo<; likeness;
  from their supposed  resemblance to a couch.
Clitoris.  A part of the female pudenda $ enclosed by the la-
  bia majora ; from x.Xtt<t> to enclose or hide.
Colon. The first of the  large intestines;  from kuXov, quasi
  xo/Aev, from MiMi hollow.
Coracoid.  From x«fos£ a crow, and £*£>$ resemblance ; shaped
  like the beak of a crow.
Coronary. From corona a crown.  The vessels of the heart,
  stomach, &c. are so called because they surround the parts
  in the manner of a crown.
Cotyloid. From kotvXv the name of an old measure, and eths
 jesemblance : resembling the kotule.
Cranium. The skull; xpxviov, quasi, ttxpxvtov, from »xpx the head.
Cremaster. A muscle so called ; from x^ifAxa to suspend, be-
  cause it suspends the testicle.
Cribriform. From cribrum a sieve, it being perforated like a
  sieve. 
Glossary.
417
Cricoid. Annular, round like a ring; from *f <xes a ring and
  ciSos likeness.
Cuboides.  A bone of the foot; from kvGos a cube,  and ti^os
  likeness ; because it resembles a cube.
Cuneiform. Some bones  are so called ; from cuneus a wedge,
  and forma likeness ; being shaped like a wedge.

                           D.
Deltoid. A muscle resembling  the  Greek letter A : from A,
  and et&s resemblance.
Diaphragm. The muscle which separates the thorax from the
  abdomen ; from hxtyxrlu to divide.
Diarthrosis. A moveable connexion of bones; from foxgOgou
  to articulate.
Digastric. From <hs twice,  and yxrue a  belly; having two
  bellies.
Diploe. The spongy substance between the  two tables of the
  skull ; from hsrxov  to double.
Duodenum. The first  portion of the small intestines; so call-
  ed because the ancients supposed that it did not exceed
  the breadth of twelve fingers;  from duodenus, consisting
  of twelve.
Dura Mater. The outermost membrane of the brain ;  called
  dura, because  it is much harder than the other membranes,
  and mater,  from  the  idea of the ancients that it was the
  source of all the other membranes.

                           E.
Embryo. The child in the womb is so called before the fifth
  month, after which  it  is termed foetus; from e^vu to bud
  forth.                              r            ,   A
Enarthrosis.  An articulation of bones ; from <» in, and xe9e°>
  a joint or articulation.
Enteric. Belonging to the intestines ; from »*-«{•» an entrail
  or intestine.
Epidermis. The scarf or outermost skin; from em upon, and
  hew the skin.
Epididymis.  The small  oblong body which lies above the tes-
  ticles ;  from esri upon, and JV^V>« a testicle.
Epigastric.  The superior  part of the  abdomen; from  e«n
  upon, and yxsve the stomach.
Epiglottis, A cartilage of the larynx so called;  from w upon,
  and yW?,« the aperture of the larynx, being situated upon
  the glottis.
   Vol. ii.                53 
41 rt
Glossary.
Epiphysis, A portion of bone growing upon another bone, but
  separated from it by a cartilage : from ex< upon, and <pvu
  to grow.
Epiploon.  The membranous viscus of the abdomen, which co-
  vers the intestines, and hangs to the bottom of the  stomach;
  from im-KXta to swim upon.
Ethmoid.  From  s6fu>i a sieve, and ufa resemblance;  being
  perforated like a sieve.
                          F.
Fascia. An expansion, enclosing other parts, like  a band ;
  from fascis a bundle.
Falciform. Shaped like a sithe ; from falx, a sithe.
Fasciculus. A little bundle, dim. of fascis a bundle.
Fauces. The plural of faux, the top of the throat.

                          G.
Ganglion. TxfyXtei, a knot in the course of a nerve.
Gastrocnemius. The muscle which forms the thick of the leg;
  from yxwe a belly, and *v«^ the leg.
Genio. Names  compounded with this  word belong to mus-
  cles which are attached  to the chin, as geno-glossus—geno-
  hyoideus, &c.; from ym<ov the chin.
Ginglymus. An  articulation;  from yifyXvf*.oi a hinge.
Glenoid cavity. From y*w> a cavity, and  ufof resemblance.
Glosso. Names compounded with this word belong to muscles
  which are attached to the tongue ; as glosso-pharyngeus__
  glosso-staphilinus, &c.; from yXwro-x the  tongue.
Glottis. The superior opening of the  larynx at the bottom of
  the tongue ; from yxurjx the tongue.
Glutssus.  The name of a muscle ; from yA»T«$ the buttocks.
Gomphosis. To^wn^ a  species of immoveable connexion of
  bones;  from yomtys a nail, because one bone is fixed  in an-
  other bone like a nail in a board.

                          H.
Helix. The outward circle of the ear; from uXta to turn  about.
Hepar. The liver.   'Hicxe  an abdominal viscus.
Hyaloid. From uxXo* glass, and uhi likeness ; the capsule of
  the vitreous humour of the eve is so called, from  its  trans-
  parent and glassy appearance.
Hymen. The membrane situated at the entrance of the vir-
  gin vagina ; from 'Ypn* Hymen, the god of marriage.
Hyoides.  A bone of the tongue, so called  from  its resem-
  blance to the Greek v; from v, and ««&»s resemblance. 
Glossary.
419
Hypoclwndrium. That part of the body which lies under the
  cartilages of the spurious ribs ; from «*•• under, and xovfyos
  a cartilage.
Hypogastric. The lower region of the fore part of the abdo-
  men ; from uxo under, and yxwe. the stomach.

                            I.
Ileon.  A portion of the small intestines ; from uxtu to turn ;
  being always convoluted.
Ischium. The part of the os innominatum upon which we sit;
  from t<r%vu to sustain.
                            L.
Lacuna.  The excretory duct of the glands of the urethra and
  vagina ;  from lacus a channel.
Lambdoidal suture. So called because it is  shaped like the
  letter A; from A, and ufa resemblance.
Larynx. The superior part of the windpipe; AǤt/ygthe larynx.

                            M.
Masseter.  A muscle of the face, which assists  in  the action
   of chewing; ft«o-c-«ef**i to chew.
Mastoid. From fww«s a teat, and eihs likeness ; shaped like a
   nipple or teat.
Mediastinum.  The production of the pleura, which divides
   the  thorax into  two cavities ; from medium the middle,
   quasi in medio stare.
Mesentery. The  membranes to which the intestines are at-
   tached ; from /*eo-os  ihe middle,  and weto*  an intestine, be-
   cause it is in the middle of the  intestines.
Mesocolon, that part of the mesentery in the middle of the
   colon ; from jtus-a? the middle, and *eAov the colon.
Metacarpus. That  part of the hand  between the carpus and
r  fingers ; from i*.trx after, and xxgirot the wrist.
Metatarsus. That  part of the  foot  between  the tarsus and
   toes ;  from perx  after, and Txes-os the tarsus.
Myto. Names  compounded with this word belong to muscles
   which are attached  near the grinders,  as mylo-hyoideus,
   Sac.; from f*.vM a grinder tooth.

                            O.
 Odontoid.  Tooth-like; from «fe< a tooth, and «fcs resemblance.
 CEsophagus. The canal leading from the pharynx to the sto-
   mach ; from <w« to carry, and 4>*y* to eat; because it car-
   ries the food into the stomach. 
420
Glossary.
Olecranon.  The elbow, or head of the ulna; from *>Xn*i the
  cubit, and xgxvov the head.
Omentum.  An abdominal viscus; so called from omen a guess,
  because the soothsayers prophesied from the inspection of
  this part.
Omo. Names compounded with this word  belong to muscles
  which  are attached to the scapula,  as omo-hyoideus, &c
  from ufMt the shoulder.
Omoplata.  The scapula  or shoulder blade; from  «jk.«s the
  shoulder, and tf*.xtvs broad.
Osteology. The doctrine  of the bones; from os-t«» a bone, and
  Aoyos a discourse.

                           P.

Pancreas.  A viscus of the abdomen ; so called from its fleshy
  consistence; from n-xv all, and xgexi flesh.
Parenchyma.  The substance of some of the viscera was so
  called, from •xxgiytcvo to pour through.
Parotid Gland. From nxex near, and «&« the ear; because it
  is situated near the ear.
Pelvis.  A bony cavity shaped like a basin; from irtxvs a basin.
Pericardium.  The  membrane  which surrounds the heart;
  from irtet around, and kx$ix the heart.
Pericranium.  The membrane  which covers the bones of the
   skull;  from met around, and xexviov the cranium or head.
Periosteum. The membrane which surrounds the bones; from
   irtgi around, and ereov a bone.
Peristaltic motion of the intestines; from weetteXXw to contract.
Peritoneum. The membrane lining  the  abdomen, and cover-
   ing its viscera; from Tregneivv to extend around.
 Phalanx.  The bones of  the fingers and toes are called pha-
   lanxes,  from their  regular situation, like a $*A*yf, or ar-
   rangement of soldiers.
 Pharynx. A membranous bag at  the  end of the mouth; «t«
   tu <piet», because it conveys the food into the stomach.
 Phrenic or diaphragmatic nerve. <pe."ts the diaphragm ; from
   <pew the mind ; because the  ancients supposed it to be the
   seat of the mind.
 Pia Mater. The  innermost membrane of the brain, so called
   because it embraces the brain as a careful mother folds her
   child.
 Pleura. The  membrane lining the thorax; nXevex the side.
 Plexus.  A kind of net-work of vessels or nerves; from  plecto
   to weave together. 
Glossary.
421
Psoas. A muscfe so called ;  from -^ox the loin, being situa-
  ted in  the loins.
Pterygoid process.  From ^t/f a pen or wing, and uSo* like-
  ness, so called from its likeness to a pen or wing.
Pylorus.   The lower orifice of the  stomach, which opens into
  the intestines; from yrvXom to guard  an entrance, because
  it guards as it were the entrance of the bowels.

                            R.

Raphe. A suture ; from  pxnlu to sew.
Renes. The kidneys,  x*o m peiv,  because through them the
  urine flows.
Retina. The net-like  expansion of the optic  nerve, on the
  inner surface of the eye; from rete a net.
Rhomboides. A muscle so called from its shape; from ^k,£««,
  a geometrical figure, whose sides  are  equal but not right-
  angled, and eths a likeness.
Rotula. The knee-pan; a dim. of rota a wheel, from its shape.

                            S.
Sacrum.  A bone so called ; from sacer sacred, because it was
  once offered in sacrifices.
Satvatella. A vein of the foot, so called because it was thought
  that opening it preserved  health,  and  cured  melancholy;
  from salvo to preserve.
Sanguis. The blood ; «w« m o-xkv yvtx,  because  it preserves
  the body.
Sartorius. A muscle so called, because tailors cross their legs
  with it; from sartor a tailor.
Scapha.  The depression of the outer ear before the anti-he-
  lix; from rxxipi) a little boat or  skitf.
 Scaphoides.  A bone of  the carpus, so called from its resem-
  blance to a skill'; from e-**^ a  skiff, and etfos  likeness.
 Sclerotic. A term applied to the outermost or hardest mem-
  brane of the eye ; from ricXygou to make hard.
 Sesamoid bones. From  <rt)vxf*.ti a  grain,  and  tih<; likeness ;
  from their resemblance to the semen sesami.
 Sigmoid. Parts are so called from their resemblance to the
   letter 2; from 2, the  letter Sigma, and eihs likeness.
 Sphenoid. From t^jj* a wedge, and e<(5es likeness ; shaped like
   a wedge.
 Sphincter. The name of several  muscles, whose  office is to
   shut up the aperture around which  they are placed from ;
    trpiyyco tO Shut Up.
 Splanchnic.  From era-Aay^ves, an entrail. 
422                    Glossary.
Symphysis. A connexion of bones; from c-tfupvu to grow to-
  gether.
Synarthrosis. A connexion of bones; from <rm with, and xp6p»t
  a joint.
Synchondrosis. A species of union of bones by means of car-
  tilage ; from <w with, and wvtyos a cartilage.
Synneurcsis.  A species of connexion of bones  by means of
  membrane ; from  <rui with, and »*vpo«anerve; because mem-
  branes, ligaments, and tendons, were by the ancients con-
  sidered as nerves.
Syssarcosis. A species  of connexion  of bones  by means of
  muscle; from a-w with, and <rxe% flesh.
Systole. The contractile motion of the heart and arteries; from
  a-va-nxxx to contract.
                           T.
Tendon. From ram to extend.
Thorax. ©»?«|. The breast or chest.
Thyroid. From 6ve.eos a shield, and n&« likeness; shaped like
  a shield.
Trachea. The windpipe ;  so called from its roughness; from
  Tf«^f« rough.
Trochanter. A process of the thigh-bone, so called from r^a?
  a wheel.
                           U.
Ulna. A name for the cubit; from aXtn the cubit.
Ureter.  The canal which conveys the urine from the kidney
  to the bladder; from ae«» urine.
Urethra. The passage through which the urine passes from
  the bladder ; from veov the urine.
Uvea. The posterior lamen of the iris, so called because in
  many animals it  is of the colour of unripe grapes ; from
  uva an unripe grape.
Uvula.  The conical substance which hangs  down  from the
  middle of the soft palate :  so called from its resemblance
  to a grape.  A  dim. of uva a grape.
                           V.
Valves.  From valvse folding doors.
Vertebrae. The bones of the spine are so called ; from verto
  to turn.
                           X.
Xiphoid. So called  from the  resemblance to a sword ; from
  |'4>as a sword, and e«Jes  likeness.
                           Z.
Zygoma. The  cavity under  the zygomatic  process of the
  temporal bones;  from £t>y«« a yoke. 
ALPHABETICAL INDEX TO  VOLUME II.
                      Page.
Aorta            50 and 236
Adhesion of lungs        73
Abdomen                 82
         regions  of      86
         contents of      85
         situation of vis-
           cera          87
Acini of liver           132
Arteries, structure of    226
Artery, axillary         262
         aorta thoracic  270
             abdominal 274
         adipose       281
         anastomotic   292
         anterior tibial 294
         basilic        259
         bronchial      270
         carotid       239
               external 240
               internal 250
         callous        256
         cervical      261
         circumflex     564
         coeliac         275
         capsular       280
         circumflex  of
            ilium       289
               of  thigh 291
         emulgent      280
         epigastric     288
         facial          242
         femorial       289
         gastric        275
                 right   276
                 left     277
         gluteal        286
         humeral       264
          hepatic       276
          hsemorrhoidal  285
          innominata    238
                      Page.
Artery,internal maxillary 245
              mammary 257
       intercostals supe-
         rior           260
       interosseal      267
       intercostals infe-
         rior           272
       illiac primitive   282
           internal     283
       ilio lumbar      284
       iliac external    288
       internal .plantar  296
       ischiatic        286
       lingual         242
       lumbar         282
       middle of brain  255
       mammary  exter-
         nal           262
       mesenteric supe-
         rior          278
                   infe-
         rior          279
                   occi-
         pital          244
       ophthalmic       252
       oesophageal      271
       obturator        285
       pharyngeal  infe-
          rior           243
       phrenic         274
       pudic  internal    287
              external    290
       profunda femoris 290
       perforating      291
       popliteal        292
        posterior tibial   295
        peroneal        295
        plantar external  296
        radial           266
        stylo-mastoid    245 
424
INDEX.
Artery, subclavian      256
       scapular superior 260
               internal 263
       spiral           265
       splenic          277
       spermatic       281
       sacral middle    282
             lateral    284
       thyroid  superior 241
               inferior  258
       temporal        249
       ulnar           268
       uterine          286
       vertebral        258
Arterial system, plan of 297
Abdominal viscera, nerves
  of                   368
Absorbents,  structure of 371
            of  lower ex-
             tremity  376
            of  abdomen 381
            of  thorax    389
            of  head and
              neck      391
            of  upper ex-
              tremity   393
Absorption,  cutaneous   395

Black glands             64
Bile                    141
Bladder of female      213
Blood vessels in general 223
Blood                  401
     colouring  matter of 404
Cavities of nose
Csecum
Colon
Corpus pampiniforme
Corpora cavernosa
Corpus spongiosum
Canal of urethra
Clitoris
Canalis arteriosus
Cavae
Coronary veins
  4
118
119
174
186
188
190
201
220
299
299
Chorda tympani Crassamentum	335 403
Duodenum Ductus communis Dartds Ductus venosus Descending cava	111 141 173 220 300
External nose Eustachion tube Epididymis	2 11 177
Fauces Foetus, thorax of heart of lungs of abdomen of	28 69 69 69 217
Female organs of genera-
  tion                  200
Fallopian tubes         209
Gums	16
Glandulse molares	26
Glottis	34
Gastric liquor	101
Great intestines	117
Gall bladder and duct	139
Glandulse renales       154
Ganglions              321
         of Gasser      327
         sphino palatine 329
         cervical        361
         semilunar      367
Glands, structure of    408
Glossary               415

Heart                   50
      malformations of   72
      nerves of         363
Hepatic duct           139
Hymen                202
Hottentots, peculiarity of 216
Intestines
              104
villous coat of 105
divison of     109 
1ND
ex.                425
Intestines, small	110	Nerves, lumbar	353
Integuments of penis	195	laryngeal superior	339
Ilium	113	maxillary inferior	332
.		superior	329
Jejunum	113	musculo cutane-	
Kidneys	155	ous median	348 348
Larynx	31	ninth pair	342
arteries and nerves		olfactory 6.	323
of	35	optic	324
Left auricle	55	ophthalmic	327
ventricle	56	obturator	355
Lungs	65	parvagum	338
Legallois on the heart Liver	79 128	recurrent radial	339 350
ligaments of	130	sixth paii-	333
Labia externa	201	seventh pair	334
Lacteals	389	sacral	356
		sciatic	358
Mouth	14	sympathetic	36t
Mammae	41	splanchnic	367
Mediastinum	46	third pair	325
Muscular fibres of heart	57	tibial posterior	360
Mesentery	115	ulnar	349
Male organs of generation 171			
Nose	1	(Esophagus Omentum	94 125
nerves of	8	Orifice of urethra	167
Nerves of liver	136	Ovarips	210
Neck of the bladder	167	\J V t*l ivo	
Nerves, structure of	319	Parotid gland	25
accessory	347	Pharynx	37
of arm	348	Pleurae	45
of brain	323	Pericardium	49
cervical	343	Pulmonary arteries and	
circumflex	351	veins	61
crural	355	Peritoneum	90
cardiac	363	Pylorus	102
of diaphragm	S46	Pancreas	141
dorsal	352	Prostate gland	113
eighth paii-	336	Penis	184
fourth pair fifth pair fibular	325	Prepuce	196
	326	Placenta	221
	359	Plexuses	321
glossopharyngeal 337		pulmonary	340
internal cutaneous 351		brachial	347
Vol. ii.		54	
 
I
426
INDEX.
Plexuses lumbar         354
         cardiac         366
         solar           367
Rima glottidis            34
Right auricle             52
      ventricle           53
Rectum                 122
Round ligaments         209
Schneiderian membrane     5
Sinuses of nose           12
Soft palate               17
Salivary glands           25
Submaxillary gland       26
Sublingual gland          26
Saliva                   26
Sabatier on foetal circula-
  tion                   75
Stomach                 96
         lymphatics and
           nerves of     103
Spleen                  145
Scrotum                171
Serum                  402
Spermatic cord          173
Tongue                  18
        papillae of         20
        blood vessels of   23
        nerves of         24
Throat                  28
Tonsils                  29
Thyroid gland            37
Thorax                  41
Trachea                 62
Thymus gland            69
Tunica vaginalis         175
        albuginea        176
Testicle                177
        descent of       218
Thoracic duct           387
Uvula
Urinary organs
Ureters
Urinary bladder
Urethra of male
 17
154
160
162
188
Urethra of female	202
Uterus	205
changes of,	in
pregnancy Umbilical arteries	214 219
Venae cavae	61
Valve of colon	120
Vena Portarum	134
Vessels of liver	133
Vas deferens	180
Vesiculae seminales	181
Vagina Veins, structure of	203 233
distribution of	298
Vena azygos Veins, axillary anomalies of	301 308 317
basilic	308
cephalic Cava inferior	308 309
capsular circumflex	312 314
      external jugular  306
      emulgent         312
      external iliac     314
      epigastric        315
      external saphena  316
      femoral          315
      hepatic          311
      hypogastric       313
      intercostal superior 303
      primitive iliac    313
      jugular internal   304
      lumbar          313
      middle sacral     313
      mesenteric superior 311
      phrenic inferior   310
Vena portarum          311
Veins, pulmonary       317
      subclavian       307
      splenic          311
      spermatic        312
      saphena major    315
      vertebral         304
      vesical          313 
ANATOMICAL PLATES.
EXPLANATION OF THE PLATES OF OSTEOLOGY.
                        Plate II.

       Fig. 1. A Front-view of the Male Skeleton.
  A,  The os frontis.  B, The os parietale.   C, The Coronal
suture. D, The squamous part of the temporal bones.  E,The
squamous suture.  F, The zygoma.  G, The mastoid process.
H, The temporal process of the sphenoid bone.  I, The orbit.
K, The os malae. L, The os maxillare superius. M, Its nasal
process.  N, The ossa nasi. 0, The os unguis.  P, The maxilla
inferior.  Q, The teeth, which are sixteen in number in each
jaw.  R, The seven cervical vertebrae, with their intermediate
cartilages.  S, Their Transverse processes.   T, The twelve
dorsal vertebrae, with their intermediate cartilages.   U, The
five lumbar vertebrae.  V, Their transverse process.  W, The
upper part of the os sacrum. X,  Its lateral parts.  The holes
seen on its fore part are the passages of the undermost spinal
nerves and small vessels.   Opposite to the holes, the marks of
the original divisions of the bones are seen.  Y, The os ilium.
Z, Its crest or spine,  a, The anterior spinous processes, b, The
brim of the pelvis,  c, The ischiatic notch, d, The os ischium.
e, Its tuberosity, f, Its spinous process, g, Its crus.  h, The
foramen thyroideum. i, The os pubis, k, The symphysis pubis.
1, The crus pubis, m, The acetabulum, n, The seventh or last
true rib.  o, The twelfth or last false rib. p, The upper end of
the sternum,  q,  The middle piece, r, The under end, or car-
tilago ensiformis. s, The clavicle,  t, The internal surface of
the scapula, u, Its acromion,  v, Its coracoid process, w,  Its
cervix, x, The glenoid cavity, y, The os humeri, z, Its head
which is connected to the glenoid cavity.  1,  Its internal  tu-
bercle. 2, Its internal tubercle. 3,  The groove for lodging the
long head of the biceps muscle of the arm.  4, The internal 
428  Explanation of the Plates of Osteology.

condyle.  Between 4 and 5, the trochlea. 6, The radius.  7,
Its head.  8, Its tubercle.  9, The ulna.  10, Its  coronoid
process.  11, 12, 13, 14, 15, 16, 17, 18, The carpus; compo-
sed of os naviculare, os lunare, os cuneiform, os pisiforme,
o» trapezium, os trapezoides, os magnum, os unciforme.  19,
The five bones of the metacarpus.  20, The two bones  of the
thumb.  21, The three bones of each of the fingers.  22, The
os femoris.  23,  Its head.  24, Its cervix.  25, The trochan-
ter major.  26, trochanter minor.  27, The internal condyle.
28, The external condyle,  29, The  rotula.   SO, The tibia.
31, Its head. 32, Its tubercle.  33, Its spine.  34,  The mal-
leolus internus.  35, The fibula.  36, Its head. 37,  The mal-
leolus externus.   The tarsus is composed of.  38, The astra-
galus; 39, The os calcis;  40, The os naviculare; 41,  Three
ossa,  cuneiformia, and the os  cuboides, which  is not seen in
this figure.  42, The five bones of  the metatarsus.  43, The
two bones of the great toe.  44, The three bones of each of
the small toes.
           Fig. 2.  A  Front-view of the Skull.
  A,  The os frontis.  B, The lateral  part of the os frontis,
which gives origin to part of the temporal muscle.  C, the su-
perciliary ridge.  D, The superciliary hole through which the
frontal vessels and nerves pass.  EE, The orbitar processes.
F,   he middle of the transverse suture.   G, The upper part
of the orbit.  H, The foramen opticum.   I, The foramen la-
cerum.   K, The inferior orbitar fissure.   L, The os unguis.
M, The ossa nasi.  N, The os maxillare superius. O,  Its na-
sal process.  P, The external orbitar hole through which the
superior maxillary vessels and nerves pass.  Q, The os malae.
R, A passage for small vessels into or out of, the orbit.  S,
The under part of the left nostril.   T, The septum narium.
U, The os spongiosum  superius.  V, The os spongiosum in-
ferius.  W, The edge of the alveoli, or spongy sockets for the
teeth.  X, i he maxilla inferior.   Y, The passage for  the in-
ferior maxillary vessels and nerves.
            Fig. 3. A  Side-view of  the Skull.
   A, The  os frontis.  B,  i he coronal suture.  C, The os pa-
rietale. D, An arched ridge which gives origin to the temporal
muscle.  E, The squamous suture. F, The squamous part of
the temporal bone: and further forwards, the temporal process
of the sphenoid bone. G, The zygomatic  process of the tempo-
ral bone.  H, i he zygomatic suture. 1, Tue mastoid  process of
the temporal bone. K, i he meatus auditorius externus. L, The
orbitar plate of the frontal bone, under which is seen the trans- 
      Explanation of the Plates of Osteology. 429

verse suture.  M, The pars plana of the ethmoid bone. N, The
os unguis.  O, The right os nasi. P, The superior maxillary
bone. Q, its nasal process.  R, The two dentes incisores.  S,
The dens caninus. T, The two small molares. U,  The three
large molares. V, The os malse.  W, The lower jaw.  X, Its
ang'e.  Y,  The coronoid process.  Z, The condyloid process
by which the jaw is articulated with the temporal  bone.
     Fig. 4. The posterior and right side of the Skull.
   A, The os frontis.  BB, The ossa parietalia.  C,  The sagit-
tal suture.  D, The parietal hole, through which a  small vein
runs to the superior longitudinal sinus.  E, The lambdoid su-
ture.  FF, Ossa triquetra.  G, The os occipitis.  II, The squa-
mous part of the temporal bone.  I, The mastoid process.  K,
The zygoma.  L, The os malae. M, The temporal  part of the
sphenoid bone, N, The superior maxillary bone and teeth.
     Fig. 5. The external surface of the Os Frontis.
   A, The convex part.   B, Part of the temporal  fossa.   C,
The external augular process.  D, The internal angular pro-
cess.  E, The nasal process.  F, The superciliary arch.   G,
The superciliary hole.   H, The orbitar plate.
     Fig.  6.  The internal surface of  the Os Frontis.
   AA, The serrated edge which assists to  form the coronal
suture.   B. The external angular process.   C, The internal
angular  process.  D, The  nasal  process.   E, The  orbitar
plate.   F, The cells which correspond with those of the  eth-
moid bone.  G, The passage from the frontal sinus.  H, The
opening  which receives the cribriform plate of the ethmoid
bone.  I, The cavity which lodges the  fore part of the brain.
K, The spine to which the falx is fixed.   L, The groove which
lodges the superior longitudinal sinus.
                        Plate III.
           Fig,  1. A Back-view of the Skeleton.   /
   AA, The ossa parietalia.  B, The sagittal suture.  C,  The
lambdoid suture.  D, The occipital bone.  E, The squamous
suture. F, The mastoid process of the temporal bone.  G, The
os malae.  II, The palate plates of the superior maxillary bones.
1, The maxilla inferior.  K, The teeth of both jaws.  L,  The
seven cervical vertebrae.   M, Their  spinous processes.   N,
Their transverse and oblique processes.  O, The last of  the
twelve dorsal vertebrae.  P, The filth or last lumbar vertebra.
 Q. The transverse processes. R, The oblique processes.  S,The
 spinous process.  T, The upper part of the os sacrum.  U, The
 posterior holes which transmit small blood vessels and nerves. 
 430  Explanation of the Plates of Osteology.

 V, The under part of the os sacrum which is covered by a
 membrane.   \V, The os coccygis.  X, The os ilium.  Y, Its
 spine or crest. Z, The ischiatic notch, a, The os ischium,  b,
 Its tuberosity, c,  Its spine, d, The os pubis,  e, The foramen
 thyroideum. f, The seventh or last true rib. g, The twelfth or
 last false rib. h, The clavicle, i, The scapula, k, Its spine.  1,
 Its acromion, m, Its cervix, n, Its superior costa.  o, Its pos-
 terior costa. p, Its inferior costa. q, The os humeri,  r, The ra-
 dius,  s, The ulna, t, Its olecranon,  u, All the bones of the
 carpus,  excepting the os pisiforme, which is seen in plate II.
 fig.  1. v, The five bones of the metacarpus,  w, The two bones
 of the thumb, x, The three bones of each of the fingers, y, The
 two sesamoid bones at the root of the left thumb,  z, The os
 femoris.  1, The trochanter major. 2, The trochanter minor.
 3, The linea aspera. 4, The internal condyle. 5, The exter-
 nal condyle.  6 6, The semilunar cartilages. 7, The tibia.  8,
 The malleolus internus.  9, The fibul. 10, The malleolus ex-
 ternus.  11, The tarsus.  12, The metatarsus. 13, The toes.
  Fig. 2. The external  Surface of the Left Os Parietale.
   A, The convex smooth surface.  B, The parietal hole.  C,
 An arch made by the beginning of the temporal muscle.
       Fig. 3. The  Internal Surface of the same bone.
   A, Its superior edge,  which, joined with the other, forms
 the sagittal suture.  B, The anterior edge which assists in the
 formation of the coronal suture.  C, The inferior  edge for
 the squamous suture. D, The  posterior  edge  for the lamb-
 doid suture.   E, A  depression made by the lateral sinus.  F,
 The prints of the arteries of the dura mater.
   Fig. 4. The external Surface of the Left Os Temporis.
   A, The squamous part. B, The mastoid process.   C, The
 zygomatic process.   D,  The styloid process.  E, The petro-
 sal process.   F, The meatus auditorius externus.   G, The
 glenoid cavity for the articulation of the lower jaw.  H, The
 foramen stylo-mastoideum for the portio dura of the seventh
 pair of nerves.  1, Passages for blood vessels into the  bone.
 K, The foramen mastoideum through which a vein goes to
 the lateral sinus.
  Fig. 5. The Internal Surface of the Left Os Temporis.
  A, The squamous part; the upper edge  of which assists in
 forming the squamous suture.  B, The mastoid process.  C,
The styloid process.  D,  The pars petrosa.  E, The entry of
the seventh pair, or auditory nerve.  F, The fossa, which lodges
 a part of the lateral sinus. G, The foramen mastoideum. 
      Explanation of  the Plates of Osteology. 431

Fig. 6. The External Surface of the Osseous Circle, which
        terminates the meatus auditorious externus.
  A, The anterior part.   B, A small part of the groove in
which the membrana tympani is fixed.
  N. B. This, with the subsequent bones of the ear, are here
delineated as large as the life.
   Fig. 7. The Internal Surface of the Osseous Circle.
  A, The anterior part.   B, The groove in which the mem-
brana tympani is fixed.
Fig. 8. The Situation and Connexion of the Small Bones of
                        the Ear.
  A, The malleus.  B, The incus.  C, The os orbiculare.
D, The stapes.
Fig. 9.  The Malleus,  with its Head, Handle, and Small
                      Processes.
Fig. 10. The  Incus, with its Body, Superior and Inferior
                      Branches.
             Fig. 11.  The Os Orbiculare.
Fig. 12.  The Stapes, with its Head, Base, and two  Crura.
 Fig. 13. An Internal View of the Labyrinth of the Ear.
  A, The hollow part of the cochlea, which forms a share of
the meatus auditorious internus. B, The vestibulum.  CCC,
The semicircular canals.
      Fig.  14.  An External View of the Labyrinth.
  A, The semicircular canals.  B, The fenestra ovalis which
leads into the vestibulum.  C,  The fenestra rotunda which
opens into the cochlea. D, The different turns of the cochlea.
   Fig. 15. The Internal  Surface of  the Os Sphenoides.
  A A, The temporal processes. BB, The pterygoid proces-
ses.   CC, The spinous processes.  DD, The anterior  clinoid
processes.  E, The posterior clinoid  process.  F, The ante-
rior process which joins the ethmoid bone. G,  The sella tur-
cica for lodging the glandula pituitaria.  H, The foramen op-
ticum.   K, The foramen  lacerum.   L, The foramen  rotun-
dum.  M, The foramen ovale.  N, The foramen spinale.
   Fig.  16. The External Surface of the Os Sphenoides.
  AA, The temporal processes. BB, The pterygoid proces-
ses.  CC, The spinous processes.   D, The processus azygos.
E, The small triangular processes which  grow from the body
of the bone.  FF, The orifices  of the sphenoid sinuses.  G,
The foramen lacerum.   H, The foramen rotundum.   I, The
foramen ovale.  K, The foramen pterygoideum. 
432  Explanation of the Plates of Osteology.

     Fig. 17. The External View of the Os Etiimoides.
  A, The nasal lamella.  BB, The grooves between the nasal
lamella and ossa spongiosa superiora.  CC, The ossa spongi-
osa superiora.  DD, The sphenoidal cornua.  See Fig. 16. E.
     Fig. 18. The Internal view of the Os Ethmoides.
  A, The crista galli. B, The cribriform plate, with the dif-
ferent passages of the  olfactory nerves.  CC,  Some of the
ethmoidal cells.   D, The right os planum.  EE, The  Sphe-
noidal cornua.
         Fig. 19.  The right Sphenoidal Cornu.
          Fig. 20. The left Sphenoidal Cornu.
    Fig. 21. The External Surface of the Os Occipitis.
  A, The upper part of the bone.  B, The superior arched
ridge.   C, The inferior arched ridge.   Under the arches are
prints made by the muscles of the neck.  DD, The two con-
dyloid processes which articulate the head with the spine.  E,
The cuneiform process.  F, The foramen  magnum through
which the spinal marrow passes.  GG, The posterior condy-
loid foramina which transmit veins into the lateral sinuses.
HH, The foramina lingualia for the passage of the ninth pair
of nerves.
    Fig. 22. The Internal Surface of the Os Occipitis.
  AA, The two sides which assist to form the lambdoid suture.
B, The point of the cuneiform process, where it joins the
sphenoid bone. CC, The prints made by the posterior lobes of
the brain. DD, Prints made by the lobes of the cerebellum.
E, The cruciform ridge for the attachment of the process of the
dura mater.   F,  The course of the superior longitudinal si-
nuses.   GG, 1 he course of the two lateral sinuses.  H, The
foramen magnum.  II, The posterior  condyloid foramina.
                       Plate IV.
          Fig. 1. A Side-view of the Skeleton.
  A A, The ossa parietalia.  B, The sagittal suture. C, The qs
occipitis. DD, The lambdoid suture.  E, The squamous part
of the temporal bone.  F, The mastoid process. G, The meatus
auditorius externus.  H, The os frontis.  I, The os malae.  K,
The os maxillare superius.  L, The maxilla inferior.  M, The
teeth of both jaws.  N, The seventh, or last cervical vertebra.
0, The spinous processes.   P, Their transverse and oblique
processes.  Q, The twelfth or last dorsal vertebra.   R, The
fifth, or last lumbar vertebra.  S, The spinous processes.  T,
Openings between the vertebrae for the passage of the spinal
nerves. U, The under end of the os sacrum.  V, The os coc- 
      Explanation of the Plates of'Osteology. 43J

cygis.  W, The os ilium. X, The anterior spinous processes
Y, The posterior spinous processes. Z, Ischiatic notch,  a, The
right os ilium,  b,  The ossa pubis,  c, The tuberosity of  the
left os ischium,  d, The Scapula,  e, Its spine, f, The os hu-
meri,  g, The radius.  h,The ulna, i, The carpus, k, The me-
tacarpal bone Of the  thumb.  1, The metacarpal bones of the
fingers, m,  The two bones of the thumb,  n, The three bones
of eaeh of the fingers, o, The os femoris. p, Its head,  q, The
trochanter major,  r,  The external condyle, s, The rotula. t,
The tibia, u, The fibula, v, The malleolus externus. w, The
astragalus,   x, The os calcis.  y, The os naviculare.  z, The
three ossa cuneiforma.   l,The os cuboides.  2, The five me-
tatarsal bones.  3, The  two bones of the  great toe.   4, The
three bones  of each of the small toes.
Fig. 2. A view of the  Internal Surface of the Base of the
                         Skull.
   AAA, The two tables of the  skull with the  diploe.  BB,
The orbitar  plates of the frontal bone.  C, The crista galli,
with cribriform plate of the ethmoidal bones on each  side of
it, through which the first pair of nerves pass.  D, The cunei-
form process of the occipital bone.   E, The cruciform ridge.
F, The foramen magnum for the passage of the spinal mar-
row.   G, The zygoma,  made by the joining of the zygomatic
processes of the os temporum and os malae.  H, The pars squa-
mosa of the os temporis.  I, The pars mammillaris.  K, The
pars petrosa.  L, The temporal  process of the sphenoid bone.
MM, The anterior clinoid processes.   N, The posterior cli-
noid process.  O, The sella turcica.  P, The foramen opticum
for the passage of  the optic nerve  and ocular artery of the
left side.   Q, The foramen lacerum,  for the third, fourth
sixth, and first of the fifth pair of nerves and ocular vein.  R,
The foramen rotundum, for the  second of the fifth pair.   8,
The foramen ovale, for  the third of the fifth pair.  T, The
foramen spinale, for  the principal artery of the dura  mater.
U, The entry of the  auditory nerve.  V, The passage for the
lateral sinus.  W, The passage of the eighth pair of  nerves.
X, The passage of the ninth pair.
Fig. 3.  A View of  the External Surface of the Base of the
                         Skull.
   A,  The two dentes incisores of the right side.  B, The dens
caninus. C, The two small molares. D, The three large  mo-
lares. E, The foramenincisivum, which gives passage to small
blood vessels and nerves.  F, The palate plates of the ossa
maxillaria and palati, joined by the longitudinal and trans-
verse palate sutures  G, The foramen palatmum postenus, t':i
   Vol. v                 55 
434  Explanation  of the Plates of Osteology.

the palatine vessels and nerves.  II, The os maxillare superius
of the right side.  I, The os malae. K, The zygomatic process
of the temporal bone.  L, The posterior extremity of the ossa
spongiosa.   M, The posterior extremity of the vomer which
forms the back part of the septum nasi. N, The pterygoid pro-
cess of the right side of the sphenoid bone. 00, The foramina
ovalia. PP, The foramina spinalia. QQ, The passages of the
internal carotid arteries. R, A hole between the point of each
pars petrosa and cuneiform process, of the occipital bone, which
is filled up with a ligamentous substance in the recent subject.
S, The passage of the left lateral sinus. T, The posterior con-
dyloid foramen of the  left side.  U, The foramen mastoideum.
V, The foramen magnum.  W, The inferior orbitar fissure.  X,
The glenoid cavity, for the articulation of the lower jaw.  Y,
The squamous part of the temporal bone.  Z, The mastoid
process, at  the inner side of which is a fossa for the posterior
belly of the digastric muscle,  a, The styloid process,  b, The
meatus auditorius externus.   c,  The left condyle of the occi-
pital bone,  d, The perpendicular occipital spine,  ee, The
inferior horizontal ridge of the occipital bone,  ff, The supe-
rior horizontal ridge, which is oppposite to the  crucial ridge
where the longitudinal sinus divides to form the lateral sinu-
ses,  ggg, The lambdoid suture,  h,  The left squamous su-
ture,  i, The parietal  bone.
      Fig. 4.  The anterior surface of the Ossa Nasi.
  A, The upper part which joins the  os frontis.   B, The un-
der end, which joins the cartilage of  the nose.    C, The in-
ner edge, where they join each other.
    Fig. 5. The posterior surface of  the Ossa Nasi.
  A A, Their cavity, which forms part of the arch of the nose.
BB, Their ridge or spine, which projects a  little to be fixed
to the fore part of the  septum narium.
Fig. 6. The external surface of the Os Maxillare Superius
                     of the left side.
  A, The nasal process.  B, The orbitar plate.   C, The un-
equal surface which joins the os malae.  D, The external orbitar
hole.  E, The opening into the nostril.  F, The palate-plate.
G, The maxillary tuberosity.  H,  Part of the os palati.  I
The two dentes incisores. K, The dens caninus.   L, The two
small dentes molares.  M, The three large dentes molares.
Fie. 7. The internal surface of the Os Maxillare Superius
                     and Os Palati.
  A, The nasal process.  BB, Eminences for the connexion
of the os spongiosum inferius.  D, The under end of the la-
chrymal groove. E, The antrum maxillare:  F, The nasal spine 
      Explanation of the Plates of Osteology.  435

between which and B is  the cavity of the nostril.   G, The
palate-plate.   H, The orbitar  part of the os palati.  I, The
nasal plate.  K, The suture which  unites the maxillary and
palate bones. The pterygoid process of the palate bone.
   Fig. 8. The external surface of the right Os Unguis.
  A, The  orbitar part.   B, The  lachrymal  part.   C, The
ridge between them.
   Fig. 9. The internal surface of  the right Os Unguis.
  This  side of the bone has a furrow opposite to the external
ridge; all  behind this is irregular, where it covers part of the
ethmoidal cells.
     Fig. 10. The external surface of the left Os Mal^e.
  A, The superior orbitar  process.   B, The  inferior orbitar
process.  C, The malar process.  D, The zygomatic process.
E, The  orbitar plate.  F, A passage for small vessels into or
out of the orbit.
     Fig. 11. The internal surface of the left Os Malje.
  A, The superior orbitar process.   B, The inferior orbitar
process.  C, The malar process.  D, The zygomatic process.
E, The internal orbitar plate or process.
 Fig. 12.  The external surface of the right Os  Spongiosum
                        Inferius.
  A, The anterior part.  B, The hook-like process  for cover-
ing part of the  antrum maxillare.  C, A small process which
covers part of  the under end  of the lachrymal  groove.  D,
The inferior edge turned a little outwards.
Fig. 13. The internal surface of the Os Spongiosum  Inferius.
  A, The anterior extremity.  B, The upper edge which joins
the  superior maxillary and palate bones.
Fig. 14^  The  posterior and external surface of the right Os
                         Palati.
  A, The orbitar process.  B, The  nasal lamella.  C, The
pterygoid process.   D, The palate process.
 Fig. 15. The interior and external surface of  the right Os
                         Palati.
   A, The orbitar process.  B,  An opening through which the
 lateral  nasal vessels and nerves pass. C, The nasal lamella.
 D, The pterygoid process. E, The posterior edge  of the pa-
 late process for the connexion of the velum palati.  F, The
 inner edge by  which the two ossa palati are connected.
           Fig. 16.  The right side of the Vomer.
   A, The upper edge which joins the nasal  lamella of the 
-I.Jti  Explanation of'the Plates of Osteology.

ethmoid bone and the middle cartilage Of the nose.   B, The
inferior edge, which is connected  to the superior maxiuarv
and palate borres.  C, The superior and posterior part which
receives the processes azygos of the sphenoid bone.
            Fig, 17. The Maxilla Inferior.
  A, The chin.  B, The base and left side.  C, The angle.
D, The coronoid process.  E, The condyloid process. F, Tho
beginning of the inferior maxillary  canal of the right  side,
for'the entry of the nerves  and blood vessels.   G, The ter-
mination of the left canal.  11, The two dentes incisores.  I,
The dens caninus. K, The two small molares.  L, The three
large molares.
        Fig.  18. The different classes of the Teeth.
  1, 2, A fore and back view of the two anterior dentes in-
cisores of the lower jaw,   3, 4, Similar  teeth of the .upper
jaw.  5, 6,  A fore and back view of  the dentes canini. 7, 8,
The anterior dentes molares.   9, 10, 11, The posterior den-
tes molares.  12, 13, 14, 15, 16, Unusual appearances in the
shape and size of the teeth.
     Fig. 19. The external surface of the Os Hyoides.
  A, The body.   BB, The  cornua.   CC, The  appendices.
                       Plate V.
Fig. 1. A Posterior View of  the Sternum and Clavicles,
  with the ligament connecting the clavicles to  each other.
  a, The posterior surface of the sternum,  bb, The broken
end of the clavicle,  cccc, The tubercles near the extremity
of each clavicle,  d, The ligament connecting  the clavicles.
Fig. 2. A Fore-view of the Left Scapula, and a half of the
             Clavicle, with their Ligaments.
  a, The spine of the scapula, b, The acromion, c, The infe-
rior angle,   d, Inferior costa.  e, Cervix,  f, Glenoid cavity
covered with cartilage for the arm-bone, gg, The capsular liga-
ment of the joint, h, Coracoid process,  i, The broken end of
the clavicle,  k, Its extremity joined to the acrimon.   1, A
ligament coming out single from the acromion to the coracoid
process, m, A ligament coming out single from the acromion,
and dividing into two, which are fixed to the coracoid process.
Fig. 3. The Joint of the elbow of the left arm, with the Li-
                        gaments.
  a, The os humeri,  b, Its internal condyle,  cc, The two
prominent parts  of its trochlea appearing through the capsu-
lar ligament,  d, The ulna,   e, The radius,  f, The part of
the ljgament includin"; the head of the radius* 
      Explanation of the Plates of Osteology.  437

Fig. 4. The Bones of the Right Hand, with the Palm in view.
  a, The radius,  b, The ulna,  c, The scaphoid bone of the
carpus,  d, The os lunare.  e, The os cuneiforme.  f, The os
pisiforme.  g, Trapezium,  h, Trapezoides. i, Magnum,  k,
Unciforme.  1, The four metacarpal bones  of the fingers,  m,
The first phalanx,  n, The second phalanx,   o, The third
phalanx, p, The metacarpal bone of the  thumb, q, The first
joint,  r, The second joint.
Fig. 5.  The posterior View of the bones of the Left Hand.
  The explication  of Fig. 4. serves for this figure; the same
letters pointing out the same bones, though in a different view.
Fig. 6. The Upper Extremity of the Tibia, with the Semilunar
 Cartilages  of the Joint of the Knee, and some Ligaments.
  a, The strong ligament which connects the rotulato the tu-
bercle of the tibia,  bb, The parts of the extremity of the ti-
bia, covered with cartilage, which appear within the semilu-
nar cartilages,  cc, The semilunar cartilages,  d, The two
parts of what is called the cross ligament.
 Fig. 7. The Posterior view of the Joint of the Right Knee.
  a, The os femoris cut  b, Its internal condyle,   c, Its ex-
ternal condyle, d, The back part of the tibia, e, The superior
extremity of the fibula,  f, The edge of the  internal semilunar
cartilage, g, An oblique ligament, h, A large perpendicular
ligament,  i, A ligament connecting the femur and fibula.
Fig. 8.  The Anterior view of the Joint of the Right Knee.
  b, The internal  condyle,  c, Its external condyle,  d, The
part of the os femoris, os which the patella moves,  e, A per-
pendicular ligament,  ff, The  two  parts of the crucial liga-
ments,   gg, The edges of the two moveable semilunar carti-
lages,  h, The tibia,  i, The strong ligament of the patella.
k,  The back part of it where the fat has been dissected away,
1, The external  depression,  m, The  internal one.  n, The
cut tibia.
  Fie. 9. A View of the inferior part of the Bones of the
                       Right Foot.
   a, The great knob of the os calcis. b, A prominence on its
outside, c, The hollow for the tendons, nerves and  blood ves-
sels, d, The anterior extremity of the os  calcis. e, Part of the
astragalus,  f,  Its head covered with cartilage, g, The internal
prominence of the os naviculare. h, The os cuboides. i, The
os  cuneiform internum; k,—Medium:  1,—Externum,  m,
The metatarsal bones of the four lesser toes,  n,  The first—o,
The second—p, The third phalanx of the four lesser toes.  q. 
 438  Explanation of the Plates of Osteology.

 The metatarsal bones of the great toe.  r, Its first—s, Its se-
 cond  joint.
  Fig. 10. The Inferior Surface of the two large Sesamoid
        Bones, at the first Joint  of the Great Toe.
 Fig.  11. The Superior View of the Bones of the Right Foot.
   a, b, as in  Fig. 9. c, The superior head of the astragalus.
 d, &c. as in Fig. 9.
 Fig.  12. The view of the Sole of the Foot, with its ligaments.
   a, The great knob of the os calcis.  b, The hollow for the
 tendons, nerves, and blood vessels,  c, The sheaths of the
 flexores pollicis and digitorum longi opened,  d, The strong
 cartilaginous ligament supporting  the head of the astragalus.
 e, h,  Two ligaments which unite  into one,  and are fixed to
 the metatarsal bone of the great toe.  f,  A ligament  from
 the knob of the os calcis to the metatarsal  bone of the little
 toe.   g, A strong triangular ligament,  which supports the
 bones of the  tarsus,   i, The ligaments of  the joints of the
 five metatarsal bones.
  Fig. 13.  a, The head of the thigh bone of a child,  b,  The
ligamentum rotundum connecting it to the acetabulum,  c,
The capsular ligament of the joint with its  arteries injected.
d  The numerous vessels of the mucilaginous gland injected.
 Fig.  14.  The Back-view of the  Cartilages of the Larynx,
                  with the Os Hyoides.
  a, The posterior part of the base of the os hyoides.  bb, Its
 cornua. c, The appendix of the right side, d, A ligament sent
out from the appendix of the left, side, to the styloid process
of the temporal bone,   e, The union of the base with the left
cornu.  ff, The posterior sides  of (g) the thyroid cartilage.
hh, Its superior cornua.  ii, Its inferior cornua.   k, The cri-
coid cartilage. 11, The arytenoid cartilages,  m, The entry into
the lungs, named glottis, n, The epiglottis,  oo, The superior
cartilages of the  trachea, p, Its ligamentous back part.
Fig. 15. The superior Concave surface of the  Sesamoid Bones
  at the first joint of the Great Toe, with their Ligaments.
  a, Three sesamoid  bones, b, The ligamentous substance in
 which thev are formed. 
Explanation of the Plates of the Muscles.  439
          EXPLANATION OF PLATES VI. and VII.

                       PLATE VI.

  Fig. 1. The Muscles immediately under the common te-
guments  on the anterior part of the body are  represented on
the right side; and on the left side the Muscles are seen
which come in view when the exterior ones are taken away.
  A, The frontal muscle. B, The tendinous aponeurosis which
joins it to the  occipital; hence both named occipito-frontalis.
C, Attollens aurem.  D, The ear.  E, Anterior auris. FF, Or-
bicularis  palpebrarum.  G,  Levator labii superioris alaeque
nasi. H,  Levator anguli oris. I, Zygomaticus minor.  K, Zy-
gomatics major.  L, Masseter.  M, Orbicularis oris.  N, De-
pressor labii inferioris.  O, Depressor anguli oris.  P, Bucci-
nator.  QQ, Platysma myoides.  RR, Sterno-cleido-mastoi-
deus.  S, Part of the trapezius.  T, Part of the scaleni.
  Superior Extremity.—U, Deltoides.  V, Pectoralis ma-
jor.  W,  Part of the latissimus dorsi. XX, Biceps flexor cu-
biti. YY, Part of the triceps extensor. ZZ, The beginning of
the tendinous  aponeurosis, (from the biceps,)  which is spread
over the muscles of the fore-arm. aa, Its strong tendon insert-
ed into the tubercle of the radius, bb, Part of the brachialis in-
ternus.   c, Pronator radii teres,  d, Flexor carpi radialis.  e,
Part of the flexor carpi ulnaris.  f, Palmaris longus.  g, Apo-
neurosis  palmaris.  3, Palmaris brevis. 1, Ligamentum carpi
annulare. 2 2, Ahductor minimi digiti. h, Supinator radii lon-
gus. i, The tendons of the  thumb,  k, Abductor pollicis.  1,
Flexor pollicis longus.  mm, The tendons of the flexor sublimis
perforatus, profundus perforans, and lumbricales.  The sheaths
are entire in the right  hand,—in the left cut open to show the
tendons  of the flexor profundus perforating the sublimis.
  Muscles not referred to—in the left superior extremity.—
n, Pectoralis minor, seu serratus anticus minor,   o, The two
heads of (xx) the biceps, p, Coraco-brachialis.  qq, The long
head of the triceps extensor cubiti.  rr, Teres  major,  ss, Sub-
scapularis. tt, Extensores radiales.  u, Supinator brevis.  v,
The cut  extremity of the pronator teres,  w,  Flexor sublimis
 fierforatus.  x, Part of the  flexor profundus,   y,  Flexor pol-
 icis longus.   z, Part of the flexor pollicis brevis. 4, Abduc-
tor minimi digiti.  5, The four lumbricales.
   Trunk,—6, Serrated extremities of the serratus anticus ma 
440  Explanation of the Plates of the Muscles.

jor.  7 7, Obliquus externus abdominis.  8 8, The linea alba.
9, The umbilicus.   10, Pyramidalis.  11 11, The  spermatic
cord.  On the left side it is covered by the cremaster.  1212,
Rectus abdominis.   13, Obliquus internus.   14 14, &c.  In-
tercostal muscles.
   Inferior Extremities.—ad, The gracilis,   bb, Parts of
the triceps,  c c, Pectinalis.  d d, Psoas magus,  e e, Iliacus in-
ternus. /, Part of the gluteus medius. g, Part of the glutaeus
minimus,  h, Cut extremity of the rectus femoris. ii, Vastus
externus.  k, Tendon of the rectus femoris.  / /, Vastus inter-
nus. * Sartorius muscle. ** Fleshy origin of the tensor vaginae
femoris or membranosus.  Its tendinous aponeurosis  covers
(i) the vastus externus on the right side,  mm, Patella,  nn,
Ligament or tendon from it to the  tibia,   o, Rectus femoris.
p, Cruraeus.  q q, The tibia,  r r, Part of the Gemellus,  or gas-
trocnemius externus. sss, Part of the soleus or gastrocnemius
internus. t, Tibialis anticus. it, Tibialis posticus,  vv, Pero-
naei muscles, ww. Extensor longus digitorum pedis, xx, Ex-
tensor longus pollicis pedis,  y, Abductor pollicis pedis.
Fig. 2. The Muscles, Glands, &c. of  the Left Side of the
   face and neck, after the common Teguments  and Platys-
   ma myoides have been taken off.
   a, The frontal muscle,   b, Temporalis and temporal arte-
ry,  c, Orbicularis palpebrarum,  d, Levator labii superioris
alaeque nasi,  e, Lavator anguli oris,   f, Zygomaticus.   g,
Depressor labii inferioris.   h, Depressor anguli oris,  i, Buc-
cinator,  k, Masseter.  11, Parotid gland,   m, Its duct,   n,
Sterno-cleido-mastoideus.  o, Part of the trapezius, p, Ster-
no-hyoideus. q, Sterno-thyroideus. r, Omo-hyoideus.  f, Le-
vator scapulae,  it, Scaleni.  u, Part of the splenius.
 Fig. 3. The Muscles of the Face and Neck in view after
             the exterior  ones are  taken away.
   aa, Corrugator supercilii.  b, Temporalis,  c, Tendon of
the levator palpebrae superioris.  d. Tendon of the orbicula-
ris palpebrarum,   e, Masseter.  f,  Buccinaor.  g, Levator
anguli oris',  h, Depressor  labii superioris alaeque nasi, i, Or-
bicularis oris,   k,  Depressor anguli oris.  1, Muscles of  the
os hyoides.  m, Sterno-cleido-mastoideus.
Fig. 4. Some of the Muscles of  the Os  Hyoides and Sub-
                    maxillary Gland.
   a, Part of the masseter muscle,   b, Posterior head of  the
digastric,  c, Its anterior head,  d d, St«rno-hyoideus. e, Omu^
hyeideus.  f, Stylo-hyoideus. gt Submaxillary gland in sit'i 
    Explanation of the Plates of the Muscles. 441

        Fig. 5. The Submaxillary Gland and Duct.
  a, Musculus mylo-hyoideus. b, Hyo-glossus.  c, Submax-
illary gland removed from its place,  d, Its duct.
                       Plate VII.
  Fig. 1. The Muscles immediately under the common te-
guments on the posterior part of the body, are represented on
the right side j and on the left side the Muscles are seen
which come in view when  the exterior ones are taken away.
  Head.—AA, Occipito-frontalis.  B, Attollens aurem.  C,
Part of the orbicularis palpebrarum.  D, Masseter.  E, Ptery-
goideus internus.
  Trunk.—Right side.    FFF, Trapezius seu cucullaris.
GGGG, Latissimus dorsi.   H, Part of the obliquus externus
abdominis.
  Trunk.—Left side. I, Splenius. K, Part of the complexus.
L, Levator scapulae.  M, Rhomboides. NN, Serratus posticus
inferior.  O, Part of the  longissimus dorsi.   P, Part of the
sacro-Iumbalis.  Q, Part of the semi-spinalis dorsi.  R, Part of
the serratus anticus major. S, Part of the obliquus internus
abdominis.
  Superior Extremity.—Right side.   T,  Deltoides.  U,
Triceps extensor  cubiti.   V, Supinator longus.  WW, Ex-
tensores  carpi radialis longior and brevior.   XX, Extensor
carpi ulnaris.  YY, Extensor digitorum communis. Z, Ab-
ductor indicis.  12 3, Extensores pollicis.
  Superior Extrbmity.—-Left side, a, Supra Spinatus.  b,
Infraspinatus,   c. Teres  minor,   d, Teres major,  e, Tri-
ceps extensor cubiti.  ff, Extensores carpi radialis.  g, Supi-
nator brevis. h, Indicater.  123, Extensores pollicis. i, Ab-
ductor minimi digiti. k, Interossei.
  Inferior Extremity.—Right side.   1, Glutaeus maximus.
m, Part of the Glutaeus medius. n, Tensor vaginae femoris. o,
Gracilis, pp, Adductor femoris magnus. q, Part of the vastus
internus.  r, Semimembranosus,  s, Semitendinosus. t, Long
head of the biceps flexor cruris,  uu, Gastrocnemius externus
seu gemellus,  v, Tendo Achillis.  w, Soleus seu gastrocne-
mius internus. xx, Peronaeus longus and brevis.  y, T^ons
of the flexor longus digitorum pedis;—and under them  flexor
brevis digitorum pedis, z, Abductor minimi digiti pedis.
  Inferior Extremity.—Left side, m, n, o, pp,q, r, s,t, v,
ww, xx, v, z, Point the same parts as in the right side, a, Pyn-
formis.  66, Gemini,  cc, Obturator mternus. d, Quadratus fe-
moris. e, Coccygaeus. /, The short head of the biceps flexorcru-
ris. ^,Plantar!s. ft, Popliteus. i,Flexorlonguspolhcispedis,

  Vol. it.                56 
442 Explanation of the Plates of the Muscles.

Fig. 2. The Palm of the Left Hand after the common Tegu-
  ments are removed, to show the Muscles of the Fingers.
  a, Tendon of the flexor carpi radialis. b, Tendon of the flex-
or carpi ulnaris.  c, Tendons of the flexor sublimis perforatus,
profundus perforans and lumbricales.  d, Abductor pollicis.
ee, Flexor pollicis longus. f, Flexor pollicis brevis. g, Palma-
ris brevis. h, Abductor minimi digiti.  i, Ligamentum carpi-
annulare.  k, A probe put under the tendons of the flexor di-
gitorum sublimisj which are performed by 1, the flexor digito-
rum profundus,  mmmm, Lumbricales.  n, Abductor pollicis.
Fig. 3. A fore-view of the foot and  Tendons of the flexores
                       Digitorum.
  a, Cut extremity of the tendo Achillis. b, Upper part of the
astragalus, c, Os calcis. d, Tendon of the tibialis anticus.  e,
Tendon of the extensor pollicis longus.   f, Tendon of the
peroneus brevis.  g, Tendons of the flexor digitorum longus,
with the nonus Vesalii.  hh, The whole of the flexor digitorum
brevis.
              Fig. 4. Muscles of the Anus.
  aa,  An outline of the buttocks, and upper part of the thighs.
b, The testes contained in the scrotum,  cc, Sphincter ani.
d, Anus,   e, Levator ani.   ff, Erector penis,  gg, Accelera-
tor urinae.  h, Corpus cavernosum urethrae.
              Fig. 3. Muscles of the Penis.
  aa,  b, d, ee, ff, h, point the same as in fig. 4.  c, Sphincter"
ani.  gg, Transversalis penis.


        EXPLANATION of PLATES VIII. IX- and X.

                      Plate VIII.

Fig. 1. Shows the Contents of the Thorax and Abdomen In
                          situ.
  1, Top of the trachea, or windpipe.  22, The internal ju-
gular veins.  3 3, The subclavian veins.  4, The vena cava de-
scendens.  5, The right auricle of the heart. 6, The right ven-
tricle.  7, Part of the left ventricle.  8, The aorta descendens.
9, The pulmonary artery.   10, The right lung, part of which
is cut off to show the great blood vessels.   11, The left lung
entire.  12 12, The anterior edge of the diaphragm.   13 13,
The two great lobes of the liver.  14, The ligamentum rotun-
dum.  15, The gall bladder.  16, The stomach.   1717, The
jejunum and ilium.  18, The spleen. 
    Explanation of the Plates of the Muscles. 443

Fig. 2. Shows the organs subservient to the Chylopoietic Vis-
       cera,—with those of Urine and Generation.
  11, The under side of  the two great lobes of the liver,   a,
Lobulus spigelii. 2, The ligamentum rotundum.  3,-The gall-
bladder.   4, The pancreas.  5, The spleen.   6 6, The kid-
neys.   7, The aorta descendens.  8, Vena cava ascendens.
99, The  renal veins covering the arteries.   10, A probe un-
der the spermatic vessels and a bit of the inferior mesentric
artery, and over the ureters.  1111, The ureters.  1212, The
iliac arteries  and veins.   13, The intestinum rectum.  14,
The bladder of urine.
Fig. 3. Shows the Chylopoietic Viscera, and  Organs subser-
       vient to them, taken out of  the body entire.
  A A, The under side of the two great lobes of the liver.  B,
Ligamentum rotundum.  C, The gall-bladder.  D,  Ductus
cysticus.  E, Ductus hepaticus.  F,  Ductus communis chole-
dochus.  G, Vena portarum.   H, Arteria hepatica.   I, The
stomach.  KK,  Venae and arteriae  gastro-epiploicae, dextrae
and sinistrae.  LL, Venae and arteriae coronariae ventriculi.
M, The  spleen.  NN, Mesocolon, with its vessels. 000, In-
testinum colon.  P, One of the ligaments of the colon, which
is a bundle of longitudinal muscular fibres.  QQQQ, Jejunum
and ilium.   RR, Sigmoid flexure of the colon with the liga-
ment continued, and over.  S, The intestinum rectum.  TT,
Levatores  ani.  U, Sphincter ani.  V, The  place to which
the prostate gland is connected.   W, The anus.
 Fig. 4.  Shows the Heart of a Foetus at the  full time, with
  the Ri^ht Auricle cut open to show the Foramen Ovale, or
   passage  between both  Auricles.
   a, The right ventricle, b, The left ventricle, cc, The out-
 er side of  the right auricle stretched out.   dd, The posterior
 side  which forms  the anterior  side of the septum,  e, The
 foramen ovale, with the membrane or valve which covers the
 left side,  f, Vena cava inferior passing through,  g, A por-
 tion of the diaphragm.
 Fig. 5.  Shows the Heart and Large Vessels of a Foetus at
                       the full time.
   a, The left ventricle,  b, The right ventricle,  c, A part of
 the rteht auricle,  d, Left auricle, ee, The right branch of the
 pTlmoW irtery. V, Arteria pulmonalis  gg, The left branch
 If the pulmonary artery, with a number of its largest branches
 dissected from the lungs, h, The canalis arteriosus,  i.  The
 arch of the aorta,  kk, The aorta descendens.  1, The left sub- 
444 Explanation of the Plates of the Muscles.

clavian artery, m, The left carotid artery, n, The right caro-
tid artery, o, The right subclavian artery, p, The origin of the
right carotid and right subclavian arteries in  one common
trunk.  q,.The vena cava superior or descendens. r, The right
common subclavian vein, s, The left common subclavian vein.
  N. B.  All the parts described in this figure are to be found
in the adult, except the canalis arteriosus.
                       Plate  IX.
Fig. 1. Exhibits the more  superficial Lymphatic Vessels of
                  the Lower Extremity.
  A, The spine of the os ilium.  B, The os pubis,  c, The
iliac artery.  D, The knee.  E, E, F, Branches of the crural ar-
tery.  G, The musculus gastrocnemius. H, The tibia.  I, The
tendon of the musculus tibialis anticus.  On the outlines, a,
A lymphatic vessel  belonging to the top of the foot,  b, Its
first division into branches,  c,  c, c, Other divisions of the
same lymphatic vessel, d,  A small lymphatic gland,  e, The
lymphatic vessels which lie between the skin and the muscles
of tne thigh,  ff, Two lymphatic glands  at the upper part of
the  thigh below the  groin,   gg, Other glands,   h, A lympha-
tic vessel which  passes by the side of those glands without
communicating with them; and bending towards the inside of
the  groin at  (1,)  opens into the lympnatic gland (k.)  11,
Lymphatic glands in the groin, which are common to the lym-
phatic vessels of the genitals and those of the lower extremi-
ty,   m, n, A plexus of lymphatic vessels passing on the in-
side of the iliac artery.
Fig. 2. Exhibits a Back-view of the Lower Extremity dis-
  sected so  as to show the deeper-seated Lymphatic Vessels
  which  accompany the Arteries.
  A, The os pubis.  B, The tuberosity of the ischium. C, That
part of the os ilium  which was articulated with the os sacrum.
D, The extremity of the iliac artery appearing above the groin.
E, The knee, FF, The two cut surfaces of the triceps muscle,
which was divided  to show the  lymphatic vessels that pass
through its perforation along with the crural artery.  G, The
edge of the musculus gracilis. H, The gastrocnemius and so-
leus much shrunk by being dried, and by the soleus being se-
parated from the tibia to expose the vessels.  I, The heel. K,
The sole of  the foot.  L, The superficial lymphatic vessels
passing over the knee, to get to the thigh.   On the outlines;
M, The posterior tibial artery,   a, A lymphatic vessel accom-
panying  the posterior tibial artery, b, The same vessel cross-
ing the artery, c, A small lymphatic gland, through which this 
Explanation of the Plates of the Muscles. 445
deep-seated lymphatic vessel passes,  d, The lymphatic vessel
passing under a small part of the soleus, which is left attached
to the bone, the rest being removed,  e, The lymphatic vessel
crossing the popliteal artery,  f, g, h, Lymphatic glands in the
ham, through which the lymphatic vessel  passes,  i, The lym-
phatic vessel passing with the crural artery, through the perfo-
ration of the triceps muscle, k, The lymphatic vessel, after it
has passed the perforation of the triceps, dividing into branches
which embrace the artery (1.)  m, A lymphatic gland belonging
to the deep-seated lymphatic vessel. At this place those vessels
pass to  the fore part of the groin where they communicate with
the  superficial lymphatic vessel,  n, A part of the superficial
lymphatic vessel appearing on the brim  of the pelvis.
 Fig. 3. Exhibits the Trunk of the Human Subject prepared
  to show the Lymphatic Vessels and the Ductus Thoracicus.
   A, The neck.  BB, The two jugular veins.  C, The vena
 cava superior.  DDDD, The subclavian veins.  E, The begin-
 ning of the aorta, pulled to  the left side by means of a ligature,
 in order to show the thoracic duct behind it.  F, The branches
 arising from the curvature of the aorta.  GG, The two  carotid
 arteries.  HH, The first ribs. II, The trachea. KK, The spine.
 LL, The vena azygos.  MM, The descending aorta.  N, The
 cceliac  artery, dividing into three branches. O, The superior
 mesenteric artery.  P, The right crus diaphragmatis.  QQ, The
 two kidneys. R, The right emulgent artery.  SS, The external
 iliac arteries, g, d,  The psoas muscles.  T, The internal iliac
 artery. U, The cavity of the pelvis. XX, The spine of the os
 ilium.  YY, The groins,  a, A lymphatic gland in the groin,
 into which lymphatic vessels from the lower extremity are seen
 to enter.  66, The lymphatic vessels of the lower extremities
 passing under Poupart's ligament, cc, A plexus of the lympha-
 tic vessels lying on each side of the pelvis,  d, The psoas muscle
 with lymphatic vessels lying upon its inside,  e, A plexus of
 lymphatics, which having passed over the  brim of the pelvis at
.  (c,) having entered the cavity of the pelvis, and received the
  lymphatic vessels belonging to the viscera contained in  that ca-
  vity, next ascends and passes behind the illiac artery to (g.)  /,
  Some lymphatic vessels of the left side passing over the upper
  part of the os sacrum; to meet those of the right side,  g,  1 he
  right psoas, with a large plexus of lymphatics lying on its inside.
  hh, The  plexus lying on each side of the  spine,   iii, Spaces
  occupied by the lymphatic glands, k, The  trunk of the  lacteals
 lying on the under side of the superior mesenteric artery. /, lhe
  same dividing into  two  branches, one of which passes  on each 
446  Explanation of the Plates of the Muscles.

side of the aorta; that of the right side being seen to enter the
thoracic duct at (m.)  m, The thoracic duct beginning from
the large lymphatics,  n, The duct passing under the lower
part of the crus diaphragmatis, and under the right emulgent
artery, o, The thoracic duct penetrating the thorax, p, Borne
lymphatic vessels joining that duct in the thorax, q, The tho-
racic duct passing under the curvature of the aorta to get to
the left subclavian vein.  The aorta being drawn aside to show
the duct   r, A plexus of lymphatic vessels passing upon the
trachea from the thyroid gland to the thoracic duct.

                        Plate X.

  Fig. 1. Represents the Under and Posterior Side of the
                 Bladder of Urine, &c.
  a, The bladder, bb, The insertion of the ureters, cc, The
vasa deferentia, which convey the  semen from the testicles to
dd. The vesiculae seminales,—and pass through e.  The pros-
tate gland,  to discharge themselves into f.  The beginning of
the  urethra.
        Fig. 2. A transverse Section of the Penis.
  gg, Corpora cavernosa penis,   h, Corpus cavernosum ure-
thral,  i, Urethra,  k, Septum penis.   11, The septum  be-
tween the corpus cavernosum urethrae  and that of the penis.
       Fig. 3.  A Longitudinal Section of the Penis.
  mm, The corpora cavernosa penis, divided by o, The sep-
tum penis,   n, The corpus cavernosum glandis, which is  the
continuation of that of the urethra.
  Fig. 4.  Represents the Female Organs of Generation.
  a, That side of the uterus which is next to the os sacrum.
1, Its fundus.  2, Its cervix, bb, The fallopian or uterine
tubes, which open into the cavityt>f the  uterus;—but the other
end is open within the pelvis, and surrounded by c c, The fim-
briae,   d d, The ovaria.  e, The os internum uteri, or mouth
of the womb,  ff, The  ligamentum rotundum, which passes
without the belly, and is fixed to the labia pudendi.  gg, The
cut edges of the ligamenta lata, which connect the uterus to
the  pelvis,  h,  The inside of the vagina,  i, The orifice of the
urethra,  k, The clitoris surrounded by (1,) The praeptium.
mm, The labia pudendi.  nn, The nymphae.
  Fig. 5. Shows the Spermatic Ducts of the Testicle filled
                     with Mercury.
  A, The vas deferens.   B, Its beginning, which  forms the 
    Explanation of the Plates of the Muscles.  447

posterior part of the epididymis.  C, The middle of the epi-
didymis, composed of serpentine ducts.  D, The head or an-
terior part of the epididymis unravelled,   e e e e, The whole
ducts which compose the head of the epididymis  unravelled.
ff, The vasa deferentia.   gg, Rete testis, hh,  Some recti-
linear ducts which send oft' the vasa deferentia.  i i, The sub-
stance of the testicle.
Fig. 6. The right Testicle entire, and the Epididymis  filled
                      with Mercury.
  A, The beginning of the vas deferens. B, The vas deferens
ascending towards the abdomen.  C, The posterior part of the
epididymis, named globus minor.   D, The spermatic vessels
enclosed in cellular substance.  E, The body of the epididy-
mis. F, Its head, named globus major. G, Its beginning from
the testicle.  H, The body of the testicle, enclosed in the tu-
nica albuginea.

               EXPLANATION  of PLATE XI.
   This plate represents the Heart in situ, all the large Arte-
ries and Veins, with some of the Muscles, &c.
   Muscles, &c.—Superior Extremity.—a, Masseter.  b,
 Complexus. C, Digastricus. d,Os hyoides. e, Thyroid gland.
 f, Levator scapulae, g, Cucullaris.  h h, The clavicles, cut. i,
 The deltoid muscle, k,  Biceps flexor cubiti. cut.  1, Coraco-
 brachialis.   m, Triceps extensor cubiti.   n, The heads of the
 pronator teres, flexor carpi radiales, and flexor digitorum sub-
 limis, cut.   o, The flexor carpi-ulnaris, cut at its extremity.
 p, Flexor digitorum profundus,  q, Supinator  radii longus,
 cut at its extremity,  r,  Ligamentum carpi transversal e.  s,
 Extensores carpi radiales.  t, Latissimus dorsi.  u. Anterior
 edge of the serratus anticus major,   vv,  The inferior part of
 the diaphragm,  ww, Its  anterior edge cut. xx,  The kidneys.
 y, Transversus abdominus.  z, Os ilium.
   Inferior Extremity.—a, Psoas magnus.  6,  Iliacus inter-
 nus.  c, The fleshy origin of the tensor vagina  femoris.   dd,
 The ossa pubis cut from  each other,  e,  Musculus pectineus
 cut from its origin.  /, Short head of the triceps abductor fe-
 moris cut.  g, The great head of the  triceps,  h, The long
 head cut.  i, Vastus internus.   k, Vastus externus.   I, Cru-
 reus. m, Gemellus,  n, Sc-leus.  o, Tibia,  p, Peroneus longus.
 q, Peroneus brevis.  r, Fibula.
    Heart and Blood-vessels.—A, The heart, with the co-
 ronary artery and veins.  B, The right auricle of the heart. C,
 The aorta ascendens. D, The left subclavian artery. E, Ihe 
 448  Explanation of the Plates of the Muscles.

 left carotid artery. F, The common trunk which sends off the
 right subclavian and right carotid arteries. G, The carotis ex-
 terna, H, Arteria facialis, which sends off the coronary arte-
 ries of the lips. I, Arteria temporalis profunda. K, Aorta de-
 scendens.  LL, The illiac arteries,  which sends off MM, lhe
 femoral or crural arteries.  N. B.  The other arteries in this
 figure have the same distribution  as  the veins of the same
 name:__And generally, in the anatomical plates, the descrip-
 tion to be found on the one side, points out the same parts in
 the other.  1, The frontal vein. 2, The facial vein.  3, Vena
 temporalis profunda.  4, Vena occipitalis.  5, Vena jugulans
 externa.  6, Vena jugularis interna, covering the arteria caro-
 tis communis. 7,  The vascular arch on the palm of the hand,
 which is formed by, 8,  The radial artery and vein, and, 9,
 The ulnar artery and vein.  10 10, Cephalic vein. 11, Basilic
 vein,  that on the right side cut.  12, Median vein.   13, The
 humeral vein, which, with the median, covers the humeral ar-
 tery.   14  14, The external thoracic or mammary arteries and
 veins. 15, The axillary vein, covering the artery. 16 16, The
 subclavian veins, which, with (6 6) the jugulars, form, 17, The
vena cava superior.  18, The cutaneous arch of veins on the
fore part of the foot.  19, The vena tibialis antica, covering the
artery.  20, The  vena profunda femoris, covering the artery.
21, The upper part of the vena saphena  major.  22, The fe-
moral vein.   23 23, The illiac veins.  24 24, Vena cava infe-
rior.  25 25, The renal veins  covering the arteries.  26 26,
 The diaphragmatic veins.
              EXPLANATION of PLATE XII.

  Fig. 1. Represents the Inferior part of the Brain;—the An-
terior part of the whole Spine, including the Medulla Spina-
lis.—with the origin and large portions of all the Nerves.
  AA, The anterior lobes of the cerebrum.  BB, The lateral
lobes of the cerebrum.  CC, The two lobes of the cerebellum.
D, Tuber annulare.  E, The passage from the third ventricle
to the infundibulum.  F, The medulla oblongata, which sends
off the medulla spinalis through the spine.  GG, That part of
the os occipitis which is placed  above  (HH) the transverse
processes of the first cervical vertebra.   II, &c. The  seven
cervical vertebrae,  with their intermediate cartilages.   KK,
&c. The twelve dorsal vertebrae,  with their intermediate car-
tilages.  LLj &c. The five lumbar vertebrae, with their inter-
mediate cartilages.  M, The os sacrum.  N, The os coccygis. 
    Explanation of the Plates of the Muscles. 449

  Nerves.—1 1, The first pair of nerves, named olfactory.
which go to the nose. 2 2, The second pair named optic, which
goes to form the tunica retina of the eye. 3 3, The third pair
named motor oculi ; it supplies most of the muscles of the
eye-ball.  4 4, The fourth pair, named pathetic,— which is
wholly spent upon the musculus trochlearis of the eye.  5 5
The fifth pair divides into three branches.—The first, named
ophthalmic, goes to the orbit, supplies the lachrymal gland, and
sends branches out to the  forehead and nose___The second,
named superior maxillary, supplies  the teeth of the upper
jaw, and some of the muscles of the lips.—The third, named
inferior maxillary, is spent upon the muscles and teeth of the
lower jaw, tongue, and muscles of the lips.   6 6, The sixth
pair, which after sending off the beginning of the intercostal
or great sympathetic, is spent upon the abductor oculi.  7 7,
The seventh pair, named auditory, divides into two branches.—
The largest,  named portio mollist is  spent upon the internal
ear.  The smallest, portio dura, joins to the fifth pair within
the internal ear by a reflected branch from the second of the
fifth; and within the tympanum, by a branch from the third
of the fifth, named chorda tympani.—Vid. fig. 3. near B 8 8,
&c. The eighth pair, named par vagum,—which accompanies
the intercostal, and is spent upon the tongue, larynx, pharynx,
lungs, and abdominal viscera. 9 9, The ninth pair, which are
spent upon the tongue.  10 10, &c. The intercostal, or great
sympathetic, which is seen from the sixth pair to the bottom
of the pelvis on each side of the spine, and joining with all
the nerves of the spine;—In its progress supplying the heart,
and, with the par  vagum, the contents of the abdomen and
pelvis.   1111, The accessorius, which is spent upon the ster-
no-cleido-mastoideus and trapezius muscles.  1212, The first
cervical  nerves;—13 13, The second cervical nerves;—both
spent upon the muscles that lie on the neck, and teguments
of the neck and head.  1414, The third cervical nerves, which,
after sending off, (15 15, &c.) the phrenic nerves to the dia-
phragm, supply the muscles  and teguments that lie on the
side of the neck and top of the shoulder.  16 16, The brachial
plexus, formed by the fourth, fifth, sixth, seventh cervicals,
and first dorsal nerves : which supply the muscles and tegu-
ments of the superior extremity.  1717, The twelve dorsal,
or proper intercostal nerves,  which are spent upon the inter-
costal muscles and some of the large muscles which lie upon
the thorax.   18 18, The five lumbar pairs of nerves, which
supply the lumbar and abdominal muscles, and some of the
teguments and rausrVg of the inferior extremity.  1919, The
   Vol, it.                *7 
450 Explanation of the Plates of the Muscles.

sacro-sciatic or posterior crural nerve, formed by the two in-
ferior lumbar, and three superior of the os sacrum. This large
nerve supplies the greatest part of the muscles and teguments
of the inferior  extremity.  20, The stomachic plexus, formed
by the eighth  pair.   21 21, Branches of the solar or coeliac
plexus, formed by the eighth pair and intercostals, which sup-
ply the stomach and chylopoietic viscera.  22 22, Branches of
the superior and inferior mesenteric  plexuses, formed by the
eighth pair and intercostals, which supply the chylopoietic vis-
cera, with part of the organs of urine and generation.  23 23,
Nerves which accompany the spermatic cord.  24 24, The hy-
pogastric plexus, which supplies the organs of urine and gene-
ration within the pelvis.
Fig. 2,3,4,5, Show different Views of the Inferior part of the
  Brain, cut perpendicularly through the Middle,—with the
  Origin and large Portions of all the Nerves which pass out
  through the Bones  of the Cranium,—and the three first
  Cervicals.
  A, The anterior lobe.  B, The lateral lobe of the cerebrum.
C, One of the  lobes of the cerebellum.   D, Tuber annulare.
E, Corpus pyramidale, in the middle of the medulla oblongata.
F, The corpus olivare, in the side of the medulla oblongata.
G, The medulla oblongata.  H, The  medulla spinalis.
  Nerves.—1 2 3 4 5 6 7 8 and 9,  Pairs  of Nerves.  ' 10 10,
Nerves accessorius, which comes from—11,12, and 13, The
three first cervical nerves.
             EXPLANATION of PLATE XIII.
Fig. 1. Shows the Lachrymal Canals, after the Common Te-
         guments and Bones have been cut away.
  a, The lachrymal gland,  b,  The two puncta lachrymalia,
from which the two lachrymal canals proceed to c, The lach-
rymal sac.  d, The large lachrymal duct, e, Its opening into
the nose,  f, The carunca lachrymalis.  g, The eye-ball.
Fig. 2.  An interior View of the Coats  and  Humours of the
                         Eye.
  a a a a, The tunica sclerotica cut in four angles, and turned
back,  bbbb, The tunica choroides adhering to the inside of
the sclerotica and the ciliary vessels are seen passing over—
ce, The retina which covers the vitreous humour,  dd, The
ciliary processes, which were continued from the choroid coat.
e e, The iris  f, The pupil. 
    Explanation of the Plates of the Muscles. 451

 Fig. 3: Shows the Optic Nerves, and Muscles of the Eye.
  a, a, The two optic nerves before they meet,  b, The two
optic nerves conjoined, c, The right optic nerve, d, Muscu-
lus attollens palpebrae  6uperioris.  e, AttoUens oculi.  f, Ab-
ductor,  gg, Obliquus superior, or trochlearis.  h, Abductor.
i, The eye-ball.
       Fig. 4. Shows the Eye-ball with its Muscles.
  a, The optic nerve,   b, Musculus trochlearis.   c, Part of
the os frontis, to wliich the trochlea or pulley is fixed through
which,—d, The tendons of the trochlearis pass,  c, Attollens
oculi.  f, Adductor oculi.  g. Abductor oculi. h, Obliquus in-
ferior,  i, Part of the  superior maxillary bone to which it is
fixed,  k, The eye-ball.
Fig. 5. Represents the  Nerves  and Muscles  of  the Right
   Eye, after  part of the  Bones  of the orbit have been cut
   away.
   A, The eye-ball.  B, The lachrymal gland.   C, Musculus
abductor oculi.   D, Attollens.  E, Levator palpebrae superi-
oris. F, Depressor oculi.  G, Abductor.  H, Obliquus superior,
with its pulley.  I, Its insertion into the sclerotic  coat.  K,
Part of the obliquus inferior.  L, The anterior part of the os
frontis, cut.   M, The crista galli of the ethmoid bone.  N,
The posterior part of the sphenoid bone.  0, Transverse spi-
 nous process  of the sphenoid bone.   P, The carotid artery,
denuded  where it passes  through the bones.  Q, The carotid
artery within the cranium.  R, The ocular artery.
   Nerves.—a a, The optic nerve,—b, The third pair, c, Its
joining with a branch  of  the first branch of the fifth pair, to
form 1,—The lenticular ganglion, which sends off the ciliary
nerves, d. e e, The fourth pair, f, The trunk of the fifth pair,
g,  The first branch of the fifth pair, named ophthalmic,  h,
 The frontal branch of it.   i, Its ciliary branches, along with
 which the nasal twig is sent to the nose, k, Its branch to the
 lachrymal gland.  1, The lenticular ganglion,  m, The second
 branch of the fifth pair, named superior maxillary,  n,  The
 third branch of the fifth  pair, named  inferior maxillary,  o,
 The sixth pair of nerves—which sends off p, The  beginning
 of the great sympathetic,  q, The remainder of the sixth pair,
 spent on c, The abductor oculi.
 Fig. 6. Represents the head of a youth, where the upper part
   of the cranium is sawed off,—to show the upper part of the
   brain, covered by the pia mater, the vessels ot  which are
   minutely filled with wax.
   AA, The cut edges of  the upper part of the cranium-   B5 
 452  Explanation of the Plates of the Muscles.

 The two tables and intermediate diploe.  BB, The two hemi-
 spheres of the cerebrum.  CC, The incisure made by the falx.
 D, Part of the tentorium cerebello super expansum.  E, Part
 of the falx, which is fixed  to the crista galli.
 Fig. 7. Represents the parts of the External Ear, with the
               Parotid Gland and its Duct.
  a a, The helix, b, The antihelix.  c. The antitragus. d, The
 tragus,  e, The lobe of the ear.  f, The cavitas innominata. g,
 The scapha.  h, The concha, i i, The parotid  gland,  k, A
 lymphatic gland, which is often  found  before the tragus.   1,
 The duct of the parotid gland, m,  its opening into the mouth.
 Fig. 8. A view of the posterior part of the external ear, mea-
  tus auditorius, tympanum with its  small  bones and Eusta-
  chian tube, of the right side.
  a, The back part of the meatus, with the small ceruminous
glands,  b, The incus, c, Malleus,  d, The chorda tympani. e,
Membrana tympani.  f, The Eustachian tube,   g, Its mouth
from the fauces.
Fig. 9. Represents the anterior part of the right external ear,
  the cavity of the tympanum—its small bones, cochlea, and
  semicircular canals.
  a, The malleus,   b, Incus, with its long leg, resting upon
the stapes,  c, Membrana tympani.  d, e, The Eustachian tube
covered by part of—f f, The Musculus circumflexus palati. 1,
2, 3, The three semicircular canals. 4, The vestibule. 5, The
cochlea. 6, The portio mollis of the seventh pair of nerves.
Fig. 10. Shows the muscles which compose  the fleshy sub-
                 stance of the Tongue.
  a a, The tip of the tongue, with some of the  papillse mini-
mae. b, The root of the tongue,  c, Part of the membrane of
the tongue, which covered the epiglottis, d d, Part of the mus-
culus hyo-glossus.  e, The lingualis.  f, Genio-glossus.  gg,
Part of the stylo-glossus. 
A     TABLE
EXHIBITING  THK  DISTRIBUTION  OF THK  BRANCHES OF  THK AORTA.
> cokoxary Arteries
which are spent upon the substance of the Heart.
  The COMMON TRUNK
Of the Right Subclavian and
   Right Common Carotid.
At the Curvature,  <
The carotids are appropriated
  the head.  They proceed
  the side of the trachea, and <
  divide at the upper edge of
  the thyroid  cartilage, into
The EXTERNAL CAROTID,
  which is principally appropri- j
  ated  to the exterior of the l
  head, and the upper parts of
  the neck.   It gives off
The Sublingual

The Facia]

The Inferior Pharyngeal

The Occipital

The Posterior Auricular


The Internal Maxillary


The Temporal
 C The Thyroid Gland.  The Larynx.
 I The part* contiguous to the Os Hyoides.
 C The Tongue.  Sublingual Cland.  The Pha-
 I                 rynx.
 (The side of the Pace. Chin. Lips.  Parts under
 ?             the Lower Jaw.
 C The Pharynx and contiguous parts.
 £The cavity of the Cranium.
  The posterior part of the Cranium  externally.
 C The cavity of the Tympanum.
 I Parts contiguous to "the external Ear.
 ("The  Superior and Inferior  Maxillary bones.
J The  Fauces.  The  Pterygoid muscles. The
i Palate.  The Dura Mater.  The Interiorof the

 c The anterior ami lateral parts of the Cranium,
 j»   externally.
                            r  The Ophthalmic Artery, to the Eye and its appendages.
The INTEHNAL  CAROTID, V  Tilc  Antcrior Artery  of < Thc Rntcrior portion of the Cerebrum,
  which is appropriated  to the /       the Brain        £
  interior of the cranium; and \  The  Mi|W|e  Artery  of $ The middle, and part of the posterior portion
  sends off                   ^       ^te g^,,        £  of the Cerebrum.
7%e LEFT SUBCLAVIAN.
Each of thc Subclavians is the first portion of the great artery of the
  Upper Extremity of its respective side.
It gives off
      ,   .   f" Anterior portion of the
Internal  Mam-1   parietes of thc Tho-
The  Internal Mam-V
  mary, to the      £   'nx   T]ie M„
                  rCexcbellum.  The pos-
The Vertebral to the}   tenor portion of the
                  (_   Cerebrum.
Thc Inferior Thyroid < Thyroid Gland   Tra-
      to the        ?   <!*•■  Oesophagus
The  Superior Inter-< S.-nu of the Intercostal
      COStal, tO     <       S[iirr^.

The Cervical, to thc^   v-m-s,  &c.  on
The Sc:«i
rical. «»  "IC5  .m-im-i, ,%...  ».....

           r MuMi-..ftl.f Ntek.
iidarv tulhtsl)"  mi the tlorsum of
  The AXILLARY
Is the next portion of
  thc artery  of the
  upper extremity. It
  gives off
The Thoracic and the External
  Mammary arteries.
To thc Pectoral and other mus-
  cles on the antcrior part of the
  thorax and shoulders.

    The Scapulary Artery,
To the muscles about the sca-
  pula and  the posterior part of
     Thc Circumflex*,
To thc parts about thc upperend
 'oftheOs Humeri.
 The Profunda Humeri

   Profunda Inferior,
 To muscles on the Os
        Humeri.

The  Anastamotica to an-
 astomose with an artery
 from  below, and to the
 muscles.

At the Elbow it (rives off
The iHTJtaossaai;
 The mm

which send off
The Buoyant, ar
The Qbophagtal
The mru
The Phremt Arteries  ■
CCELIAC ARTERY
SUPERIOR MESENTERIC
Capsular Arteries  -
EMULGENTS
Spermatic, -
To the Trachea and substance of the Lungs.
To the CEsophagus.
To nine or ten of the lower intercostal spaces.
To the diaphragm.
To the stomach, liver, and spleen.
Almost all the small intestines, and part of the great.
Glandulx Hcnales.
The Kidneys.
Thc Testicles.  The Ovaries.
The left portion of the Colon, and the Rectum.
Muscles on thc loins and the abdomen.  The spine and the spinal canty.
Wliich is spent upon the Sacrum, Coccyx, and Rectum.
At the great Bifurca- <
  The PRIMITIVE 1LIACS,
One of which is divided on each
  side of the Pelvis into
The Itio Lumbar artery t
  The  EXTERNAL ILIAC,
The first portion of the great
  artery of the lower extremity, t
  which passes under Poupart's
  ligameat to the thigh, but pre-
  viously sends off
 TThc Sacrum,  internally  and <
a<   ternally.
 £The Cauda Equina.

 fThe Bladder.
o< The Uterus.
 £,The Rectum.
    fThe Muscles on the upper and
  to <  interior part of the thigh.
    £The Hip joint, &c.

    r The Muscles on the lateral and
  to <  posterior parts of the Ossa In-


    rTIie Muscles, fee. on the upper
  to <  and the posterior part of the
    C  thigh.


i offCThe Organs of Generation
  The CireumfUxa Ilii,
A small artery, which is
  spent upon the iliacus
  abdominal muscles and
  the psoas.

    The Epigastric,
Which is spent upon the
  muscles,  and integu-
  ments of the anterior
  part of thc abdomen.
  The FEMORAL

The  second portion
  of the great artery
  of the lower extre-
  mity begin at Pou-
  part's ligament. It
 The External Pudic
To the exterior parts of
  the Organs of Gene-


   The Profunda,
And  its  branches, the
  two circumflex*, to
  thc muscles on thc
  thigh.
  The POPLITEAL,
Thc third  portion of thc
  great artery, ties on the
  back of the thigh.
It sends  off the articular
  arteries, which anasto-
  mose with each other,
  and supply the contigu-

It divides into
   The A.tTxaion tibial,
Which proceeds down thc an-
  terior part of thc leg to the '
  top of the foot, from which
  it descends to the sole.  It
  sends off
      Thei
Which is near thc fibula on the
  posterior side of the interos-
  seal ligament.  It is spent
  upon
  & and thc internal ankle
o^the sole of the foot, where
t 'divides.   It sends off
A  recurrent  branch to anasto-
  mose  with  branches from

Branches to the antcrior muscles
  of the leg.
Tarsal and metatarsal branches
  to the upper part of the foot.
The muscles on the outside of

The ankle and the outside of the
Branches to thc muscles.
The  medullary  artery of the
  tibia.
The internal and the  external
  plantar arteries, to the parts
  on the sole of the foot and the
  toes.

N B The Pwwrior Tibial and is* Pe-
  roneal come off frwo U» PtpUttal by 
 
 
 
 
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