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A
 SYSTEM   OF  ANATOMY
   <jfrf ^•""%   FOR THE USE OF  /£/  C^k«^-^ / S%A <
^   STUDENTS OF MEDICINE.
BY CASPAR WISTAR, M. D.
LATE PROFESSOR OF ANATOMY IN THE UNIVERSITY OF
               PENNSYLVANIA
THIRD EDITION.
(/
fl J^-U-rt It'
WITH NOTES AND ADDITIONS.
    BY WILLIAM EDMONDS HORNER, M. D.
IDJUNCT PROFESSOR OF ANATOMY IN THE UNIVERSITY OF PENNSYLVANIA,
      MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, &C.
IN TWO VOLUMES.
       S VOL. II.  ■,-?.


      PHILADELPHIA:
PUBLISHED BY JAMES  E. MOORE.
       J. HARDING, PRINTER.

            1823.
/ 
QS
■s
                       Rj m no. (0153, ttar*

 Eastern District of Pennsylvania, to wit .-
   BE IT REMEMBERED, That on the twenty-seventh day of Octo-
 ber, in the forty-eighth year of the Independence of the United States
 of America, A. D. 1823, James E. Moore, of the said district, hath de-
 posited in this office the title of a book, the right whereof he claims as
 proprietor, in the words following, to wit:

 " A System  of Anatomy for the  use  of the Students of Medicine.  By
   " Caspar Wistar, M. D. Late Professor of Anatomy in the University
   " of Pennsylvania.  Third, edition.  With notes and additions.  By
   " William Edmonds Horner, M.  D.  Adjunct  Professor of Anatomy
   " in the University of Pennsylvania, and member of the American Phi-
   losophical Society,,fee.  In two volumes.  Volume II."

   In conformity to the act of the Congress of the United States, entituled,
" 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 encourage-
ment of learning, by securing the copies of maps, charts, and books, to
the authors and proprietors of such copies during the times therein men-
tioned,' and extending the benefits thereof to the arts of designing, en-
graving, and etching historical and other prints."
                             D. CALDWELL, Clerk of the Eastern
                                    District of Pennsylvania.
:(*■" 
CONTENTS OF VOL.  II.
                 PART VI.

   OF THE NOSE—THE MOUTH—AND THE THROAT

                 CHAPTER I.

                   Of the Nose.

                  SECTION I.
                                           Page
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
CONTENTS.
                   PART VII.

                  OF THE THORAX.

                   CHAPTER I.

           Of the general Cavity of the Thorax.

                    SECTION L
Of the Form of the Cavity of the Thorax           -    44

                   SECTION II.
Of the Arrangement of the Pleurse              -      45
Preparation of the Thorax    -              -    -    47

                   CHAPTER  II.

Of the Heart and the Pericardium, and the Great Vessels con-
                nected 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
  Vena; Cavse at their commencement     -      -      59

                   CHAPTER III.

              Of the Trachea and Lungs.

                    SECTION I.
Of the Trachea    -------    62
The Black Glands on the Bronchise                   64

                   SECTION II.
Of the Lungs......      -  65
Thorax of the Foetus     -      ...      69
Physiological Observations, &c.    -    •     -    -    71 
CONTENTS.
•V.
                   PART VIII.

                  OF THE ABDOMEN.

                    CHAPTER I.

A general view of the Abdomen and Pelvis, and their Con-
        tents ; with 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 (Esophagus, the Stomach,  and the Intestines.

                    SECTION I.
Of the GEsophagus      -                            94

                    SECTION II.
Of the Stomach   -         .....96
Of the Gastric Liquor   -      -      -■      -      ioi

                   SECTION III.
Of the Intestines       -                V -    -     104
Division of the Intestines       -      - >*           119
The Small Intestines......110
The Duodenum   -      -       -      -      -       111
Jejunum and Ileon     -    -     -    -    -    -     113
The Mesentery   -      -       -      -      -       115
Of the great Intestines.....117
The Csecum and Colon         -      -      -       118
The Rectum.......122
The Omentum          -       -      -      -       125

                   CHAPTER III.

        Of the Liver, the Pancreas, and the Spleen.
Of the Liver
SECTION I.
128 
  VI                    GoNTEMs.

                     SECTION II.
  Of the Pancreas        -      -                    141

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

                    CHAPTER IV.

      Of the Urinary Organs, and the Glandulse Renales.

                     SECTION I.
 Of the Glandulse 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 Vesiculae 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     -      -      200

                   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 of the Blood Vessels.

                     SECTION I.
 Of the Arteries                        -       -      226

                    SECTION II.
 Of the Veins      -                                233

                    CHAPTER II.

   A Particular Account of the Distribution 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 Arch 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        -                  285

                   CHAPTER III.

        Of the particular Distribution of the  Veins.

                    SECTION I.
 Of the Superior, or Descending Vena Cava, and the Veins
  which communicate with it                -    -    300

                    SECTION  II.
Of the  Inferior  Vena Cava, and the veins  connected
  with it                     -             -       309 
Vlll                  CONTENTS.
PART X.
OF THE NERVES.
Nerves of the Brain -	323
Of the Cervical Nerves - - -	343
Nerves of the Diaphragm -	346
Brachial Plexus -	347
Nerves of the Arm -	348
The Dorsal Nerves -	352
Of the Lumbar Nerves -	353
The Sacral Nerves - -	356
Sciatic Plexus --_--,	357
Great Sciatic Nerve -	358
Great Sympathetic Nerve	361
Nerves of the Heart	363
Nerves of the Abdominal Viscera - -	-" - 368
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 Neck, of the Upper Extre-
    mities, 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        -                                 «Q51 
OTOTBffi « AmATMTW*
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 up-
 per  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 concerned in their formation.
   In addition to the description of these bones, in
 the account of the bones of the head, it will be use-
 ful to  study the description of the cavities of the
 nose which follows it.  See vol. I, page 64.
   After thus acquiring a  knowledge of the  bony
 structure, the  student will be prepared  for a  descrip-
tion of the softer parts.
  Vol. II.              1 
2
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
maxillary bones, which have been already described;
(see vol. 1, 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 septum,
or partition between the two cavities of the nose.  The
anterior edge of this plate projects beyond 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  orifice of the
nose, at the junction of  the palatine processes 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 cartilage, 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 spokeu  of  as distinct
cartilages; but they  are really continuations 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, or 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 a.i oval ring, which is  placed ob-
liquely on the side of the septum : so that the extre- 
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 in-
 ternal, and projects lower down than the cartilagi-
 nous septum :  so that it is applied to its fellow juf -
 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 external  edge  of  the  partition
 between the nostrils, or the columna nasi;  which is
 very moveable upon the edge of the middle cartilage.
   The orifices of the nostrils, thus  constructed, are
dilated by that portion of the muscle, called Levator
Labii  Superioris Jilaeqiie Nasi,  which is inserted
 into the al;e nasi. 
 4          Of the Cavities of the Nose.

   They are drawn down by the depressor labii su-
 perioris alseque nasi.  They are pressed against the
 septum and the nose by the muscle called Compres-
 sor Naris, 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 muscle by
 many anatomists,  but were described by Albinus as
 a separate muscle, and called Nasalis Labii Sujje-
 rioris.
  When inspiration takes place with great force, the
 alae nasi would be pressed against the septum if they
 were not drawn out and dilated  by some of the mus-
 cles above mentioned.

                   SECTION  n.

           Of the Cavities of the Nose.
  To the description of  the osseous parts of the na-
 sal cavities in vol. I, page 64,  it  ought now to be
 added that the vacuity in the anterior part of the os-
 seous septum is filled up  by a  cartilaginous plate,
 connected 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 
Sehneiderian Membrane.           5
its secretion of mucus, or Sehneiderian 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 has  some resemblance
to periosteum; while the other surface is  soft, spon-
gy, and rather villous.  Bichat seems to  have con-
sidered this membrane as formed  of two lamina?, viz.
periosteum, and the  proper mucous membrane; but
he adds, that it is almost impossible to separate them.
  It has been supposed that many distinct glandu-
lar bodies  were to be seen in the structure  of this
membrane by  examining the surface  next  to the
bones;f but this opinion is adopted by very  few of
the anatomists of the present day.  The texture of
the membrane appears to be uniform ; and on its sur-
face are a great number of follicles of various sizes,
from which flows the mucus 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 mem-
brane is immersed in water, both on the septum and
on  the opposite surface.  They  are scattered over
the membrane  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 mucus is
effected here by vessels which are mere continuations
of arteries spread upon a  surface analogous to the

  * Conrad Schneider, a German professor, in a large work, " De
Catarrhis," published about 1660.
  f See Wiuslow, section X. No. 337. 
 "               Olfactory Nerves.
 exhalents, and not convoluted in circumscribed mass-
 es, 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 splieno-palatine foramen,
 and is therefore  called the Sphenopalatine 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  septus 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 Sehneiderian membrane; but
 they are not of much importance.
  The veins of the nose correspond with the arteries.
Those which 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 uumerous  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 eth-
moid bone, and  the os turbinatum : and in addition
to these are some intermediate filaments.
  When the  Sehneiderian 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
aforesaid  surfaces of  the  membrane for a consider-
able distance, when  they gradually sink into the
substance of  the membrane, and most probably ter-
minate on the internal villous surface; but they have
not been traced to their ultimate termination.   They
ratify 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 con-
tact  with each other. On the opposite sides, the dif-
ferent ramifications 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
delicate in the progress towards  their terminations,

   * They are entitled, Icones organorum humanorum olfactus. 
 8 Spheno-palatine and other Nerves of the Nose.

 and as observing a torturous course, with very short
 meandering flexures.
   It is to be observed that the  ramifications of the
 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 eth-
 moid, 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 olfactory 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 sending off some fibrillar, descends upon
the anterior  part of the septum to the point of the
nose.  The spheno-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.  Se-
veral small branches  also pass to the nose  from the
 palatine and  other nerves:  but  those already men-
tioned 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 opththalmic 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 Sehneiderian Membrane.     9

 factory nerve alone is concerned  in the function of
 smelling, it follows, that tliis function  must be con-
 fined to the upper parts of the nasal cavities; but it
 ought to  be  remembered, that the structure of the
 Sehneiderian membrane, in the lower parts of these
 cavities^ appears exactly like that  which is above.
   The surface  of the nasal cavities and their sep-
 tum, when covered with the Sehneiderian membrane,
 corresponds with the osseous surface formerly des-
 cribed.  The membrane covers the bones and car-
 tilage of the  septum,  so as to  make one uniform re-
 gular 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 sub-
jects, it forms a plait or fold,  which diminishes the
 aperture 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. II.              2 
10  Distribution of the Sehneiderian Membrane.

larger than the bone : and the edge of the fold there-
fore extends lower down tnan 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 sphcno-maxillary
foramen, which it closes; the periosteum, exterior to
the foramen, passing through it, and blending itself
with the fibrous surface of the Schneideriau 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 turbi-
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 Sehnei-
derian membrane lines the nose, than it is in the
bare bones.  A portion of the aperture in the bones
is closed  by the Sehneiderian 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 Sehneiderian mem-
brane.
   This aperture varies in size in different subjects,
and is ofteu 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 ap-
pears less full than it is  in  the turbinated bone.   In
this meatus, near to its anterior end, is the lower ori-
fice of the lachrymal  duct: this is simply lined by
the Sehneiderian membrane, which is continued into
it, and forms no plaits or folds that affect the orifice.

          Orifice of the Eustachian Tube.
   Immefciatety  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 afford a surface for the ex-
       pansion of the olfactory nerves; and a passage  for
       the external a»r to the windpipe, in respiration.
     The function of smelling appears to be dependent, to
       a certain degree, upon respiration.   It has been  a?- 
12        Observations respecting the Nose.

      sorted that unless the air passes in a stream through
      the nose, as in respiration, the perception of 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 optic
      and auditory  nerves, it is probable, from the appear-
      ance of  the  fibres, while they are distinguishable,
      that they are finally arranged with great delicacy.
      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 mucus is necessary as  a covering and
      defence of its surface.
    It has been ascertained,  by the investigations  of che-
      mists, that this mucus contains the same%gredients
      as the  tears  already described, viz.  animal mucus
      and water; with muriate of soda, and soda uncom-
      bined;  phosphate of lime, and phosphate of soda.
    The animal mucus, 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 mucus of the nose, if it remain there long after it
      is  secreted,  becomes much more viscid in consist-
      ence,  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 
Use of  the Sinuses of the Nose.        18
  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
  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 follow-
  ing fact is also  in  support  of it.   The celebrated
  Dessault 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  Dessault 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 seve-
  ral 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
checks 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 princi-
pally by the  palatine processes of the upper maxil-
lary and palate bones, and the soft palate, which con-
tinues backward from  them  in  the same direction.
  Below,  the cavity is  completed by several mus-
cles, which proceed from almost the whole internal
circumference of the lower jaw, and, by their con-
nexions with  each other, with the tongue and the os
hyoides, form a floor or bottom to it.   The tongue is
particularly 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, genio-
hyoideus,  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 mus-
cles, a portion 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 inside 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 cu-
ticle in other parts.  When this cuticle is separated,
the lips and the membrane of the mouth, appear to
be covered with very fine villi, which are particular-
ly apparent in some preparations of the lips after in-
jection and maceration.*"
   Under this membrane are many small  glandular
bodies of a roundish form, called glandular 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 witli 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 mem-
brane, from the orifice of the lips to the back part of
the cheeks.  Glandular bodies, like those of the lipsr
are situated immediately exterior to this membrane
of the cheeks, between it and the muscles:  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
portions 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 Thesauw?
VII. Tab- III. Fig. 5. 
 16    Gums.—Surface of the Hard Palate.

   The teeth appear  to have passed through  aper-
 tures in this membrane,  and are surrounded by it
 closely at their respective necks.
   The portion of membrane, which thus invests the
jaws, constitutes the gums;  which have now acquir-
 ed a texture very different  from  that  of  the mem-
 brane, from  which they  Were continued.   They are
 extremely firm and dense, and very vascular.   It is
 probable that their ultimate structure is  not perfectly
 understood.
  In the disease called scurvy, they tumify and lose
the firmness of their texture : they acquire a livid co-
lour, and are much disposed to hemorrhage.
  From the alveoli of the upper jaw, the lining mem-
brane 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 ad-
heres firmly to  the periosteum, and thus  is closely
fixed  to the bones.- There  is generally a ridge  on
its surface,  immediately under the suture 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
degree of that  sensibility which  is essential to the
function  of  tasting ; and,  that if  certain sapid sub-
stances  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.            1^

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 membrane
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 palatopharyngei  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 thelining 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 conuected by its basis to
the palate; but its  apex is  loose aud pendulous.
This body is covered by the lining membrane of the
mouth. It contains  mauy small glands, aud 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 the
 apex of the uvula, into which it is inserted.   By the
 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 of
 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 in  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 the circumflexi 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 situat-
ed 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-byoidei, which pass to it oblique-
from  behind  and rather from above; the  mylo-
hyoidei, which come rather anteriorly from the late-
ral 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 particular direction,  act while  the others  are
passive, the bone may be moved upwards or down-
wards, backwards or forwards, or  to either side.
This  bone may be considered as the basis  of  the
tongue; for the posterior 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;
and 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
byoglossus muscle and also  by  some  other muscular
fibres, as wrell as  by a dense membranous substance,
which appears to perform the part  of a  ligament. 
 20           Structure of the Tongue.

 This connexion is also strengthened by the continu-
 ance of the integuments from the tongue to the epi-
 glottis cartilage, to be hereafter described ; for that
 cartilage 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 consi-
 dered 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
 uuder 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 inserted 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 commenc-
ing at a short distance from its apex, and continuing
to its base.
  As the genio-hyo-glossi muscles have a consider-
able 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- 
Papillae of the Tongue.           21
nued into the posterior  and lateral 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  salivary
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 promi-
nent under the tongue ; and when the tongue is rais-
ed  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 laminae.  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
various sizes and forms, all of which are denominat-
ed  Papillae.   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

  * 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 in the intervals  of the papilla:, which, as he
supposes, occasioned the florid colour of the tongue. 
 23            Papillae of the  Tongue.

 backwards.  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
 connected.  In many of them there are follicles, or
 perforations, which have occasioned them  to be re-
 garded as glands.  They are called Papillae Maxi-
 tnae, or Capitatx.
   The papillae, 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  rounded.
 They are scattered over the upper surface of the
 tongue, in almost every part of it, at  irregular dis-
 tances 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 consi-
 der  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  anato-
 mists to the stalk of the apple, while the  papillae
 resembled the fruit;  but their ultimate  termination
 does not appear to have been  ascertained.*

  * In the explanation of the plates, referred to in the following
 sentence, Soemmering observes, that when the fibrillac of the lin-
 gual 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 papilla without
 touching a nerve. 
Blood vessels of the Tongue.
23
  Soemmering has lately published  some elegant
engraved copies of drawings of these papillae, when
they were magnified twenty-five times ; from which
it appears that a very large number of vessels, par-
ticularly of arteries, exist in them.   These vessels
are arranged in a serpentine direction, and are pro-
minent on  the surface;  but they  appear doubled,
and the most prominent part is the doubled end.—
This arrangement  of vessels is  perceptible on the
sides of the tongue, as well as on the papillae.
  Behind the  large papillae 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
linguae.  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-hyo-glossus 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 papillae 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  papillae.
  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 flesh-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  pro-
cess over a portion of the  masseter muscle, and  from
the zj^oma 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 external
carotid artery  and from its facial branch.
   From the auterior 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
cheek  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 and 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,
(here 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, after 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
between the mylo-hyoideus and  the genio-glossus
muscles along the under and inner edge of the sub-
lingual gland.   Iu 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 frsenum
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 subsequently Guy De Chauliac, Lanfranc, Achillini Berenger
 De Carpi, Charles Etienne, Casserius and several others have given
 the description of these salivary ducts, notwithstanding which Whar-
 ton, a physician of London, attributed  to himself the discovery of
 them on the bullock in 1656.--Ed.
I 
           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 ra-
ther oblique,  one edge being placed obliquely  in-
wards 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, ou  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 con-
tains some albumen, 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 bodies, 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 Glan>
dulse 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 
28          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 en-
       tirely 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 state of
       the surface of  the  mouth, more accurately  by the
       application of the tongue than of the fingers.
     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-i
       cerned in the function  of tasting, as it passes to the
       front  part of  the   surface  of the  tongue.   The
       glosso-pharyngeal  are  probably concerned in the
       same function on the posterior part, while the ninth
       pair of  nerves  seems  principally spent  upon  the
       muscular 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 continuing
       them.

  * There is a very interesting paper on this subject, in the Me
jnoirs of the Academy of Sciences for the year 1718, by Jussieu ;
in which he describes the case of a female, fifteen years  old, ex-
amined by himself, who was born  without a tongue.   In this paper
he refers to another case, described by Rolland, a surgeon of Sau-
mur, of a boy nine years old, whose tongue was destroyed by gan-
grene.  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.
4 
CHAPTER 111.
                 OF THE THKOAT.

   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
oesophagus 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 tougue  to  the  palate, and terminates near the
commencement of  the uvula.  The  posterior plait
runs from the palate obliquely downwards and back-
  fards, as it contains the palato-pharyngeus musele,
  hich  passes from the palate to the upper and pos-
terior part of the tyroid cartilage.
   In the triangular space between these ridges is si-
tuated  a glandular body, called the  Tonsil Jlmyg- 
 30            Tonsils.—Epiglottis.

 dala.  This glaud has au oval form, its longest dia-
 meter extending from  above downwards.  Its sur-
 face is rather convex, its natural colour is a pale red.
 On its surface are the large orifices of many cells of
 considerable size, which exist throughout the gland.
 These cells often communicate with  each  other, so
 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 transmis-
sion of food.
  The epiglottis, or fifth cartilage of the larynx, is
situated at the root of the tongue, in the middle, be-
tween the tonsils.   The part  which  is  in sight is
partly oval in form, and of a whitish colour.   Its po-
sition, as respects the tongue, is nearly perpendicu-
lar, 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 epi-
 glottis, from its base upwards.
  On each side of this plait, or fraenum, 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 gener^
 knowledge of the structure.  Thus, looking into vm
 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 strength 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 angular 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 ap-
plied to  it laterally, and thus partially inclose 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 promi-
nent 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 J
 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 in-
 serted into itself.  It is moved obliquely downwards
 and forwards, in a slight degree, upon  the cricoid
 cartilage 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
backwards.   They are placed upon the upper and
posterior edge of the cricoid  cartilage, near to each
other; and their  upper ends, taken together, resem-
ble the mouth of a pitcher or ewer;  from which cir-
cumstance their name is derived.   Their bases are
broad ; and on their lower surfaces is a cavity, which
 corresponds with the convex edge of the cricoid car-
 tilage, to which they are applied.   At these places,
 a regular moveable articulation is  formed, by a cap-
 sular  ligament between each  of these cartilages and
 the cricoid, in consequence of which they can be in-
 clined 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; aud 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.
33
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 carti-
lages,  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 perpendicu-
lar  position, one of its  broad surfaces  is anterior
towards the tongue, and the other posterior, towards
the opening 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
already 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
mucous ducts.
  There is a small space between the lower part of
this cartilage,  and the upper part  of the thyroid and
  Vol. II.              5 
34
Rima 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
supposed 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 cartila-
ges, 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 cartila-
ges ; 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 vacuity between  them and the lower
ligaments, so as to form a cavity on each side of the
larynx,  opening between the two ligaments, whioh
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 Rima Glottidis, or Chink of the Glottis ;
the upper aperture, formed by the fold of  the mem- 
Arteries and Nerves of the Larynx.     35
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 carti-
lages is concave.  This concavity is  occupied  in
each by a glandular substance, which lies between
the cartilage  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 se-
crete mucus.
   The  membrane, which  lines  the cavity  of the
glottis  being continued from  the mouth  and  throat,
resembles the membranes which invest those parts.
In some places, where it is in close contact with the
cartilages, it appears united  with the perichondrium,
aud acquires  more firmness and density.
   The general motions of the larynx 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.   They take place par-
ticularly in deglutition, and  in some modifications of
the voice; and also in vomiting.
  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 them.  The most important of these
muscles are  the crico-arytenoidei postici and later-
ales, the thyreo-arytenoidei, the arytenoidei obliqui,
and the arytenoideus  transversa.   Thv  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-
gaments 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 the subclavian.
   The nerves of the  larynx also come to it in  two
very  different 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
       of bread enters it.  Notwithstanding this, a flexible
       tube, or catheter,  has several times been passed into
       the windpipe  through  the rima glottidis, and  been
       endured by  the patient a considerable time.
     The cough, which occurs when these parts  are irritat-
       ed, does not appear to arise exclusively from the
       irritation of  the membrane within the glottis; for, if
       it were so, mucilaginous substances, when  swallowed
       slowly, could not  suspend it.   Their effect in reliev-
       ing cough is universally known;  and as  they are
       only applied to the surface  exterior to the glottis, it
       is evident that the irritation of this surface must also
       produce coughing.
     Several curious experiments have been made to deter-
       mine the effect of dividing the different nerves which
       go to the larynx; by which it appears that the re-
       current branches supply parts which are  essentially
       necessary to the  formation of the voice, whilst the
       laryngeal branches  supply parts which  merely in-
       fluence its modulation, or tone.  See  Mr. Haigh-
       ton's Essay  on this subject:  Memoirs of the Medical
       Society of London, Vol. III. 
        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
cricoid cartilage  and  a portion of the thyroid.  It
lies  behind the sterno-hyoidei and sterno-thyroidei
muscles. 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 sup-
plied with blood, and  receives  two arteries on each
side:  oue from the laryngeal branch of the external
carotid : 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 occurred, in which
air  has  been forced,  by violent straining, from the
windpipe into the substance of this gland.*

  *  There are two membranous expansions in the neck which
should be noticed in its dissection. The first called Fascia Superfi-
cialis lies immediately beneath the skin, may be considered as a
continuation of the fascia superficialis 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 great vessels, &c. of the superior mediastinum are placed im-
mediately 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 terminates in the oesophagus.
   It has  beeu 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 vertebrae
behind; and, opposite to the cricoid cartilage, it ter-
minates in  the oesophagus.
   If the pharynx and oesophagus be carefully dis-
sected  and detached from  the  vertebrae, preserving
the connexion of  the  pharynx with the  head; and
the head then be separated from  the  body, by di-
viding  the articulation of  the  atlas and the os occi-
pitis, and cutting 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 through the whole extent of the  poste-
rior 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 oblong:  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; aud, 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 in-
• ternal membrane is very soft and flexible, and per-
 forated  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 con-
 nected  to the  muscular stratum by a loose cellular
 membrane.
   The muscular coat consists of three different por-
 tions,  which are considered  as  so many distinct
 muscles.
   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 from the
cuneiform  process of the occipital bone, from 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 princi-
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
thyroid and  the cricoid cartilages, and  terminate
also in the  middle line.   Those which are  superior,
running obliquely upwards; the inferior, nearly in a
transverse 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
 lobuli.  Between these glandular portions a great
 deal of adipose matter is so diffused, that it consti-
 tutes 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 much  enlarged about  the
 age of puberty.   They  are also  very large during
pregnancy  and lactation;  but  after the period  of
childbearing, they  diminish  considerably.   They
are supplied with blood by the external and internal
  Vol. II,             6 
43
Mammae.
mammary  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 termiuate
on the surface of the nipple.*
  They are commonly about fifteen in number,  and
vary considerably in  size : the  largest of them be-
ing 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 preg-
nancy ; but they are very small in  subjects of a dif-
ferent 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 remarka-
ble sentiment, that some of  the  ducts  originated in
the adipose matter about the  gland, as well as in the
glandular substance.^
   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

  * Described in the 16th century, by Charles Etienne, Veralius and
Posthuis, but their uses were unknown.—Ed.
  •f See Edinburg Medical Commentaries, vol. l.page 31—a papei
 by Meckel.—Ed.
  % Elementa Physiologic 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
pregnant women it is sometimes almost black ; and
in  women who have borne children it is often brown-
ish. 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 be-
tween  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, aud the sternum. The
figure of this aperture  is between that of the circle
a d the oval; but it is made irregular by the verte-
bra, and by the upper edge of the sternum.
  When 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 t
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, aud  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 aud  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 laminae form  tlie
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-
 minae 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  laminae 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
laminae  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 mention-
 ed 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 laminae 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-
 nae 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 vertebra?:
this  is  called  the  Posterior Mediastinum.   It con-
tains a considerable portion of  the  aorta as it des-
cends  from its curve,  the oesophagus, the thoracic
duct, and the vena azygos.   The aorta is in contact
with the left lamina, and can often be seen through
it when the left lung is lifted up.
  The oesophagus, is in contact with the right  lami-
mina : 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 beginuing 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 arrange-
       ment of the pleura, as well as the connexion of these
       membranes with the parts  contained in the thorax.
       may be  studied advantageously, after the  subject
       has  been prepared in  the  manner now to be de-
       scribed.
     Take  away,  from each side, the five ribs which are
       situated between the first and last true ribs, by se-
       parating 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 di-
       rection ; so that the division of the bone may cor-
       respond with the  space between the laminae of the
       mediastinum.
     Separate  the portion of the sternum cautiously, so as 
48          Preparation of the Thorax.

      to avoid lacerating the laminae 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  pericardium; 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 laminae of the mediastinum.
    After  this preparation the  upper space between  the
      laminae of the mediastinum can be examined ; and
      the  relative situation of the trachea and the great
      vessels in it can  be understood.   The anterior me-
      diastinum can also be studied: the root of each lung,
      or its connexion with the mediastinum, may be seen
      perfectly; and the precise  situation of the  lung, in
      its proper cavity, may be well conceived.
   After this, while the portions of the sternum are sepa-
      rated,  the pericardium may  be opened,  and the
      heart brought into view: the attachment of the pe-
      ricardium, and to the mediastinum, and to the dia-
      phragm, may be  seen with advantage in this situa-
      tion.  The portions 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 con-
      tents, and the parts which constitute the roots of the
      lungs. 
CHAPTER II.
OF THE HEART AND THE PERICARDIUM, AND THE GREAT
       VESSELS CONNECTED WITH THE HEART.

                   SECTION II.

               Of the Pericardium.
  The  heart  is  inclosed by a membranous  sac,
which,  upon  a superficial view,  seems only  con-
nected with its great vessels ; but which, in fact, ad-
heres closely to the whole of its surface.  From this
surface  it is extended to those vessels; from which
it proceeds, after  the maimer of the reflected mem-
branes, and forms an inclosure that lies loosely about
the heart.  If it were dissected from the heart, with-
out laceration or wounding,  it would  be an entire
sac.
  The  pericardium,  thus  arranged,  is placed be-
tween the two laminae of the mediastinum, and ad-
heres firmly to them where they are contiguous to it:
it also adheres firmly to the diaphragm below, and
thus preserves the heart in its proper position.
  The  figure  of  the pericardium, when  it is dis-
tended,  is somewhat conical; the base being on the
diaphragm.  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
distended by injection, it often  occupies the whole
cavity of the pericardium.
  The  pericardium is composed of two laminae, the
internal of which covers  the  heart, as has been al-
ready described; while the external merely 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
transparent, 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
appendages of the  heart, while  the ventricles com-
pose the body of the viscus.
  T-ie 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 formed a tumour, protruding on the neck from under
the sternum.  This tumour had a strong pulsating motion. It dis-
appeared completely when the other hydropic symptoms were re-
lieved. 
             Connexions of the Heart.          51

  The figure of the heart  is not regularly couical;
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 body, 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 au-
ricle opens into the left  ventricle; and from this
ventricle 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 cavae, 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
making its great curve; and 4th, by the pericardium,
which  is attached to the  great  vessels and  to the
mediastinum.  By these different modes the basis of
the heart is fixed,   while its body and apex are per-
fectly free from attachment,  aud  only contiguous to
the pericardium.
  The  external surface of  the heart,  being formed 
58               Right Auricle.
by the pericardium, is very smooth : under this sur-
face 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 venae 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
cavity is considered  as consisting of  two portious:
the Auricle, strictly  speaking; and the Sinus Veno-
sus, 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 an-
terior portion of the auricle, or that which appears like
a pouch between the ventricle and the veins, is differ-
ent 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 fasciculi that
cover the whole  internal  surface: this is  also the
case with  the point, or that part  which is strictly
called auricle.

  * In this description the heart is supposed to be in its natural
position. 
Right Ventricle.
53
  These fasciculi are denominated  Musculi Pecti-
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 cover-
ed 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 coronary vein.   This orifice is
covered by another semilunar valve,  which is some-
times reticulated.
  The aperture, which forms the communication be-
tween the right auricle and 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 Valvulx 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 js 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 cf fleshy  fibres, which are of various
thickness and length.  Some of those 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 throughout their
whole length, forming ridges or eminences on it. The
columns of the two last described species are very nu-
merous.  They present an elegant reticulated 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 di-
rection near the apex.  They are all  covered by a
membrane continued from the auricle and the tricus-
pid valves ; but this membrane appears more delicate
and transparent  in the ventricle than it is in the au-
ricle.
  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 tber orifice of the
pulmonary artery, which arises |rom it near the ba-
sis of the ventricle.  This artery is very conspicuous,
externally, at the basis of the heart.
  It is very evident, upon the first inspection of the
heart, that the valvulae 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 5 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, is
a small firm tubercle, called Corpusculum Arantiu*
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 it. 
 56               Left Ventricle.

 The  valves  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
 pulmonary 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 mu*culi pec-
tinati, except in the angular process properly called
 auricle.
  These valves, and the orifice communicating with
the ventricle, resemble those which have been alrea-
dy described between the right auricle and ventricle;
but with  this difference, that the valvular ring  is di-
vided into two portions only, instead of three, which
 are called Valvulas Mitrales.  The tendinous 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 different,
 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 corpuscu-
la 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 ventri-
cles probably corresponds with the  difference be-
tween 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 Philosophical
Transactions for 1795, part 1, page 215.
   Vol. II.              8 
58            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 sur-
faces 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 aorta
immediately  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 pul-
monary artery and the  right auricle, and  continues
in a circular  course in the groove between  the right
auricle and the right ventricle, and sends off its prin-
cipal 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 between the left auricle and  ventricle.
   The great vein of  the heart opens  into the under
side of the right auricle, as has been already men-
tioned : the main trunk  of this vein passes  for some
distance 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
heavt, which opened into the different cavities on both sides of it.
  Ttiis assertion of a fact so difficult to reconcile with the general
principles of the circulation, was received with great  hesitation •. 
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 de-
nominated, from their position, Right and Left Co-
ronary.
   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 i<* very
elastic as well  as firm and strong.
   When the pericardium is removed,  these arteries
appear to proceed together  from  the  upper part  of


and although it was confirmed by some very respectable anatomists
of the last  century, it was denied by others.  Some of the anato-
mists 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 Phi-
losophical Transactions  for  1798,  Part I, by a very respectable
anatomist, Mr. Abernethy, who states  that he has often passed a
course waxen injection from the proper arteries and veins of the
heai-t into all  the cavities of that organ, and particularly  into the
Left  Ventricle.  But it was only in subjects with  diseased lungs
that this was practicable.
  The existence of this communication between the coronary ves-
sels and the great cavities of the heart seems therefore to be  proved.
The easy demonstration in  such subjects is ingeniously referred  by
Mr. Abernethy, to the obstruction of the circulation in  the lungs:
and he regards the communication  as a provision enabling  the co-
ronary vessels to unload themselves, when the coronary vein can-
not discharge freely into the right auricle* 
60 Pulmonary Artery and Veins and Venae Cavx.

the basis of the  heart: the pulmonary artery being
placed 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, arid left  part of the basis of
the right ventricle,  and proceeds obliquely back-
wards and upwards ; inclining gradually to the left
side for about eighteen or twenty lines ; when it di-
vides 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
proceeds 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 back-
ward and to the left, to a considerable distance be-
yond the pulmonary  artery.   In this course, it cros-
ses 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-
minae 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 
  Pulmonary Artery and Veins and Venae Cavx. 61

an obtuse angle with its two great branches, each of
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
lamina  of the  mediastinum,  and supported  by it.
At  a small  distance  below the upper edge  of the
sternum, it receives the trunk  formed by the left  sub-
clavian and  internal jugular vein which passes ob-
liquely  across the sternum below its inner edge, in
the upper space between the laminae of the mediasti-
num. 
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 iutimately 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 the 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
other, the edges of which are  connected by mem-
brane 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
membrane 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 oc-
cupies all the interstice  between them; so that the
cartilages 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 the 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  ra-
mifications ; for they become smaller, and finally dis-
appear, while the membranous tube continues  with-
out them, ramifying minutely, and pipbably 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 fi-
bres 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 there .is a fleshy
substauce 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-
licate 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 ramifi-
 cations of the bronchia in the lungs.
   On the posterior  membranous  portion of the tra-
 chea, where the cartilages are deficient, a conside-
 rable 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
removed from that situation.
   The reason of the deficiency in the rings, at this
posterior part, is not very obvious.* It continues in
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 Physick has advanced the opinion that it enables a person
to expel the mucus of the lungs by contracting the size of the tra-
chea, and consequently 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
 lymphatic glands.

                   SECTION  11.

                  Of the Lungs.
   There are two of these organs:  each of which
 occupies 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 me-
 diastinum  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 laminae  of
 the mediastinum.  One great branch of the trachea
 and of the  pulmonary artery  pass from the medias-
 tinum to  each lung, and enter 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
 lung to the heart.
   These vessels are inclosed  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. II.             9 
06            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
direction nearly horizontal,   lu 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
almost 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 gray; owing to the
deposition of a black  pigment in the  substance im-
mediately 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  in-
ternal  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
external membrane it is often in much smaller por-
tions, and sometimes  is arranged in lines in the in-
terstices of the lobuli,  to  be  hereafter mentioned.
It is also diffused in small quantities  throughout the
substance of the lungs. 
Structure of the Lungs.
m
   The source of this  substance, and the use of it,
 are unknown.
   The lungs are of a soft spongy texture;  aud, in
 animals that have  breathed, they  have always a
 considerable 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 manner with force, the wax  will appear like
 a concretion.
   These effects of injections prove that the mem-
 branes of which the cells are formed are very thin;
 and, of course, that their volume is  very small when
 compared 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 ex-
 tremely 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 the 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 other.   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 minute-
ly ; and it seems to have been proved within the last
 thirty years, by the united labours of chemists and
physiologists,  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 circulates 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
 distributed 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 luugs 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 laminae 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.
                   Tlie  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 large
quill, which  inclines  to the  oval form,  with its
longest 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 evident-
 ly 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
 system 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 joius
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 circu-
lation  which the foetus  carries on, by means of the
umbilical arteries and vein in the placenta.

               The Lungs of the Foetus
   Differ greatly from those of the adult.   They ap-
pear solid, as if they were composed  of the paren-
chymatous substauce 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 effects
      upon the animal economy, particularly upon the action
      of the heart,  appear to be much better understood at
      this  time than they were before the discovery of the
      composition of the atmosphere,  by 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 me-
      dicine than those which preceded them. Two of these
      publications ought to be particularly  noticed by him :
      viz.  an essay, by Dr.Edward Goodwyn, intitled, "The
      Connexion of life with respiration ;'? and—the " Phy- 
 7&             Cases of Malformation.

       siological Researches of M. Bichat upon Life an<l
       Death.  Part Second.*
     The general doctrines respecting the oxygenation or de-
       carbonation  of  the blood, and the absolute necessity
       that it should take place to  a certain degree in order
       to  preserve  life, are confirmed bv a  number of cases
       of malformation  of the heart or  the great vessels, in
       which  the structure was such that a considerable por-
       tion 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 respective 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 ag-
       gravated by muscular  exertion.  These effects have
       generally appeared to  be proportioned to the quan-
       tity of venous blood admitted into the aortic system.!
         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 pub-
lications on  this subject,  prior to 1804, from Dr. Bostock's Essay
on Respiration.—Since the publication of that ess iy several inte-
resting papers on respiration have appeared, viz. Two memoirs
by the late Abbe Spalanzani;—" An Inquiry into the Changes in-
duced on Atmospheric Air by the Germination of Seeds, &c."by
Ellis ;—two very  important communications by Messrs. Allen and
Pepysin the Transactions of the Royal Society of London for 1808
and 1809;—and " Further Inquiries into the changes induced on
Atmospheric Air."  Also by Ellis.
  f Cases of this kind are related in several of the periodical pub-
lications on medical subjects.   Two of them  were described by the
late Dr. William  Hunter in the sixth volume of Medical Observa-
tions and  Inquiries,  by a Society of Physicians in London ; one
(quoted by Dr. Goodwyn)  is in the Observationes Anatomicac of
Sandifort; and another, by Dr J  S. Dorsey, has lately been pub-
lished in the first number of the New England Journal of Medicine
and Surgery. 
Cases of Malformation.            73
commonly the effect of a diseased alte'ration  in  the
lungs.  They sometimes occur near the termination of
fatal cases of  pneumonia  or catarrh ; but a different
cause, which has not latterly been suspected, 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,
redema of the hands and feet, and several other symp-
toms.  About  seven weeks after the  commencement
of these symptoms she died ; when it was ascertained
by dissection,  that there was no unnatural communica-
tion whatever between the cavities of the heart,  and that
its valves were all in a perfect  and natural state.  The
lungs were free from tubercles,  or any  other appear-
ance of disease.  Their substance seemed more com-
pact than usual,  especially the  left lung,  although it
did not sink in water;  but they  adhered 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 exr
ternal surface of the lungs have  been found upon dis-
section 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 by M.
    Dupuytren in a late  volume of the Proceedings of the
    National Institute of France, that the oxygenation or
    decarbonation of the blood  is much affected, in respi-
    ration, 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 carbonation, during this time.
    This fact is more remarkable, because venous  blood,,
Vol.  II.                  10 
74      Effects of Venous Blood on the Heart.
contained in a bladder exposed 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 been divi-
ded, 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 stimulat-
       ing to produce the necessary excitement of the heart;
       but  on this occasion  one of his friends proposed to him
       the following  question :  Why does venous blood  affect
       the  left side  of  the heart in this injurious  manner,
       when 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 edi-
       tion. Bichat has offered a solution which  completely
       resolves this  difficulty, viz. " The  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 anima-
       tion of the heart, like  that of the other  parts of the
       body, depends upon  the state of the blood in the ar-
       teries which  penetrate its  texture.t   And while the
       heart acts, the blood of the coronary arteries  will be
       the same with that of the left ventricle.  See Bichat's
       Researches, P. II. art. 6, § 2.
     The French  Anatomists appear to entertain  some pecu-
       liar  opinions respecting the course of the blood in the
       foetus, which have a  particular relation to  the  subject
       last  mentioned. Winslow, who paid great attention to
       the  valve  of  Eustachius in the right  auricle of the
       heart,  was of opinion, that this valve was calculated

  * These Memoirs are  republished in the Eclectic Repertory
of Philadelphia for April and October 1811.
  f It  is  probable that the contents of the great cavities of the
heart have  no more effect upon  its animation than  the contents
of the stomach and bowels have Upon the animation of  those
organs. 
Sentiments of Sabatier, fyc.          75
    for some important purpose  in  the  fetal economy.*
    Although his hypothesis respecting its  particular use
    has not  been retained by  his countrymen, many of
    them  have adopted his general sentiment; and among
    others Sabatier. That learned anatomist believed that
    this valve, in the fetal state, serves to direct the  blood
    of the inferior cava, after its arrival in the right auricle,
    through  the foramen ovale into  the left auricle ;  while
    the blood of the upper cava passes directly into the right
    ventricle. His opinion seems  to be supported to a cer-
    tain degree.
      1. By  the direction  in which  the  two  columns of
    blood enter the auricle from the two venee cavse.
       2.  By the position of the Eustachian valve.
      3.  By the foramen ovale, when its valve is complete",
    us the passage through it, from the right to the left, is
    at that time oblique, and from below  upwards.
      The theory of Sabatier appears to be this : The um-
    bilical vein brings from the placenta blood which has a
    quality  essential  to the animation of the fetus. If
    there were no particular provision to the contrary, a
    large portion of this blood, after  passing from the um-
    bilical vein  by the inferior cava into the  right auricle
    of the heart,  would proceed  by the right  ventricle,
    through  the pulmonary artery and arterial canal, into
    the aorta, below the origins of the carotid and subcla-
    vian arteries; and consequently none of it would pass to
    the head and upper extremities, but a considerable part
    would return again by the umbilical arteries to the pla-
    centa.without circulating through the body: while on the
    other hand, the blood which passed by the carotid and
    subclavian arteries to  the head and upper extremities,
    returning from them to the heart by the superior cava,
    might pass  from the right auricle to the  left auricle
    and  ventricle  and the aorta, and so to the head and
    upper extremities again, without passing through the
    placenta.  But by means of  this valve,  the blood of
    the lower  cava, and  of  course  of the umbilical vein,
    is directed  to the left auriele  and ventricle and the
    aorta, by which a  considerable  portion of it will ne-
    cessarily pass to  the  head and upper  extremities :
    while the blood which returns from these parts by the
    superior cava, must consequently pass from the right

* See  Memoirs of the Acadcmv  of Sciences for 1717 and 1725. 
76
Sentiments of Sabatier, fyc.
       auricle into the right ventricle and pulmonary artery ;
       from whence a large portion of it will proceed through
       the arterial canal into the aorta beyond the carotids
       and  subclavians,  and of this portion a  considerable
       part  will go to the placenta by the umbilical arteries.
       Sabatier compares the course  of the blood in the fetus
       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 fetus and placenta
       is very analogous  to that of the double circulation  of
       the adult; the character 8 answering equally well in
       the description of  either subject.
        According to Sabatier,  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 fetus
       performs a more extensive circulation  than  that of 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 corona-
       ry 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 cannot 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 fetus whenever the circulation
       through the umbilical  cord is suspended during fifteen
       or twenty minutes : for as the placenta imparts to the
       fetal 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
Academy of  Sciences, 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 representation
 of a heart, in which the venae cavee 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 pulmonary artery  as com-
 pletely  from the left.  The canalis arteriosus, howev-
 er, passed from the pulmonary artery to the aorta, and
 the foramen ovale existed.  In this  case it is  evident
 that the pulmonary artery must have carried  back  to
 the lungs the arterial blood  which came from them by
 the pulmonary veins, 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 eavse, with  a small
 addition of arterial blood  that  passed through the
 ductus arteriosus.   Yet, with this structure, the child
 lived two months after its birth.
   A case, which had a strong resemblance to the fore-
 going, occurred  lately in Philadelphia, and was exam-
 ined by the author  of this  work.  The  venee cavse
 terminated regularly in the right auricle, and the pul-
 monary veins in the same regular  manner in the left;
 but the pulmonary artery arose from the left ventri-
 cle, and the aorta from the right.   There was no com-
 munication  between these  vessels by  a canalis  arterio-
 sus ; but a large opening existed in the septum be-
 tween the auricles.
   It is very evident,  that in this case also the  pulmo-
 nary artery must have returned to the lungs the arte-
 rial 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  cavee ; excepting
 only those portions of the arterial and venous blood
 which must have flawed reciprocally from one auricle
 into the other, and thus changed their respective situa-
 tions, 
78                 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  between the auri-
      cles, was eight or  nine  lines in diameter.  The pul-
      monary artery was larger in proportion than the 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 increased 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 push himself about the
      room; but this muscular exertion  always greatly af-
      fected his respiration.  He  attained the size  common
      to children of his age, and had generally a great ap-
      petite. For some weeks before death his legs  and feet
      were swelled.
        It is probable  that the protraction of life depended
      upon the mixture of the blood in the two auricles ; and
      that they really  were to  be  considered as one  cavity,
      in this case.
There seems reason to believe, that in adults of the com-
  mon structure, there is no passage of blood from one
  auricle to the other, when  the  foramen ovale has re-
  mained open;  because in several  persons in  whom it
  was found by dissection to  have remained open, there
  were  no  appearances during life  that indicated 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  exists there,
  and the complete occupation of the left auricle by the
  blood flowing  from the pulmonary 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 va've about it.


    Although it be admitted, that in adults with the fo-
  ramen 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 on steadi-
ly in  the fetus.   To the arguments, derived  from the
structure and the nature of the case, it  may be added,
that the pulmonary veins,  in the fetal  state, carry to
the left auricle a quantity of  blood,  not  sufficient to
fill it; while the vense ca\ee carry to  the right auricle
not only the whole blood  of the body, but of the um-
bilical cord  and placenta: some of which must  flow
into the unfilled  left  auricle, when the right auricle
becomes fully distended.
The question how far the functions of the heart and
  lungs are dependent upon the brain is very important,
  and has often been  agitated  with great zeal.  In fa-
  vour 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 deficient 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 immediate-
  ly 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 ques-
  tion to be considered as undecided, if not incapable of
  solution ; although Cruikshank and Bichat* have sta-
  ted 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 expe-
riments of Dr. Legallois, a  physician of Paris, which
  • See Cruikshank's Experiments on the Nerves and Spinal Mar-
row  of living animals; London Philosophical  Transactions for
1795. The eighth experiment  has a particular relation  to this
subject.
  Bichat's Researches, part 2, article 9.
  The Abbe Fontana has considered  this subject in his Treatise
on the Venom of the Viper, vol.  ii. page 194, English translation ^
and also in some of his other works. 
80  Humboldt and others on Legallois' Paper.

      prove, that in animals who have suffered decapitation,
      the action of the heart does not cease as an immediate
      consequence of the removal of the head ;  but  its ces-
      sation is  an indirect effect, induced by the suspension
      of Yespiration.  That respiration  is immediately  af-
      fected  by decapitation, and  depends upon the influ-
      ence 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 marrow be destroyed,  the  ac-
      tion of the heart ceases irrecoverably.
        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 deriv-
      ed from the spinal marrow; and that when this organ
      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 Imperial
      Institute of France in  1811.  The committee of that
      body to   whom they  were  referred,  viz.   Messrs.
      Humboldt, Halle  and Percy, reported that the expe-
      riments had been  repeated before  them,  at three  dif-
      ferent meetings of several hours each ; and that to
      allow themselves  sufficient  time for reflection, they
      suffered  an interval of  a  week to take place  be-
      tween  the meetings.  The  committee believe 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.
        3d. 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 imme-
      diate 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 experi-
      ments which induced 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 ac-
      tion of the heart ceases, only because respiration is un-
      der  its influence;  and if under these circumstances
      respiration  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 reconcile-
      able 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 incon-
      testably  that the motion  of the heart is independent
      of the  brain, it ought to be remembered that in cer-
      tain diseased states of the brain, where that organ ap-
      pears to be compressed, the action of the heart is often
      very irregular, and its contractions  less frequent than
      usual.
Vol. II.
11 
SYSTEM OF  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 THE 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 inclosed by the ribs, aud 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  various
 muscles which  occur between  the  lower margin of
 the thorax and the upper margin of the ossa innomi-
 nata; and by the ossa innominata, which contribute,
for the purpose, the costaa 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 psoace
 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 thorax,
 there are  no  vacuities  in it exterior to the contained
 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 of the
" Obliquus Decendens Externus." 
81
Construction of the Abdomen.
   There are also two apertures at the bottom of the
pelvis, for the orifice of the rectum and of the urethra.
In the tendons of the external oblique muscles are
two orifices, covered by the integuments, for the sper-
matic cords; and, in the foetal state, one for the um-
bilical 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*disteusion 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 abdoraf-
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, v. hen engaged  with  this subject, will
be gratified by the examination of Mr. Astley Cooper's plates re-
lating to hernisc. 
             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 various outlets of the cavity are constructed
most advantageously; otherwise hernia or protrusion
of its contents would be a daily occurrence.
   The abdomen contains, 1st. The Stomach and the
ivhole Intestinal Tube, consisting of the small and
the great intestines.
   2d.  The Assisting Chylopoietic Viscera,—the Li-
ver, the Pancreas and the Spleen.
   3. The Urinary Organs,—the Kidneys, the Ure-
ters, and the Bladder.  To which should be added
the Glandulae Renales.
   4th. The Organs of Generation iii  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 ivhole
of the Inferior Cava, and their great  ramifications;
with such of their branches  as are appropriated to
the Viscera of the Abdomen and Pelvis.
   7th. Those portions of the Par Vagum and Inter-
costal Nerves which are appropriated  to the cavity;
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 Lacteals, and their glands.
-   As the cavity of the abdomen has no natural divi- 
 86          Regions 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 subdi-
 vided into three regions.
   The  three regions of the uppermost division are
 defined with  some  precision.   Those on each  side,
 which are called the Right 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  carti-
 lages, 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 arbitrary distance above
 and  below the  umbilicus:  some choosing for this
 purpose two inches, and others  a  hand's  breadth.
 As these distances will occupy different proportions
 of the cavity in persons of different stature, other
 anatomists, with a view  to avoid this inconvenience,
 have proposed  to  connect 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 
Regions 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 advan-
tages derived from a principle which is similar in
its application to all subjects fully compensates for
this inconvenience.
  There are therefore nine of these regions: viz. The
Epigastric and the two Hypochondriac:  the Umbi-
lical,  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
sternum 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 divisions 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
regions, and from each of them is continued a tube
or duct, called  Ureter, that passes into the pelvis to
convey the  urine  to the bladder.  This  viscus, in
males, is in contact with the last portion of the great
intestine called .the Rectum, and with it occupies
almost all of the cavity of the pelvis; while in fe-
males, 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 Riac Arteries.   Each
of  these great  branches divides  again, on the side 
              Cavity of the Abdomen.           89

of the  pelvis, into  two;  viz. the External Iliac,
which passes under the  crural arch  to  the  thigh,
and  the Internal  Iliac, or  Hypogastric,  which de-
scends iuto 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 the Inferior Mesen-
teric.   Besides these vessels for the chylopoietic
viscera, the  aorta sends off  a  large branch, called
Emulgent, 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 cceliac 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, aud 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 t(ie vena cava passes  through an
   Vol. II.              12 
90
The Periloneum.
aperture in  the tendinous centre of the diaphragm
to uuite 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 intimately 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  situations by the perito-
neum; 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 Ligament, 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 invests the viscera; and that they must
consist of two laminae: and  as the blood vessels,
nerves, and absorbents,  are all posterior to the peri-
toneum, they naturally pass  between these laminae
of the mesentery.
  Some of the viscera are much more completely in-
vested with the peritoneum than others.  The sto-
mach,  liver, and spleen, arc almost  completely
surrounded by  it; and it is said  to  form  a coat for
each 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 the colon are in close  contact with the
posterior surface of the  abdomen, and the  peritone-
um only covers that  portion of their surfaces  which
looks anteriorly towards the cavity of the  abdomen,
and is not in contact 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
portiou.
  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 laminae, so thin and deli-
cate as to resemble cellular membrane, which, after
extending downwards to the lower part of the abdo- 
92              The Peritoneum.
men, are turned  backwards and upwards, and pro-
ceed in that direction until they arrive at he colon,
which  they inclose, 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
laminae,  but this cannot he  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 abuudant, and occasions the aforesaid dis-
ease—;iscites.   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 extien:i:es 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 cavity  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.   Ou the psoas
muscle it yields with but little resistance to the pas-
sage  of pus,  or any  other effused fluid, as  in the
ease of the psoas abscess. 
CHAPTER II.
OF THE OESOPHAGUS, THE STOMACH, AND THE INTESTINES.

                   SECTION 1.

               Of the (Esophagus.
  The (Esophagus is a muscular tube which passes
from the pharynx to the stomach, and is so intimately
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
surface of the nose and mouth.  From the pharynx
the oesophagus  passes downwards  between the  tra-
chea and the vertebrae.   After the bifurcation of the
trachea, it proceeds  in .contact  with the spine,  be-
tween the laminae of the mediastinum, to the  dia-
phragm, which  it passes through,  and then termi-
nates 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 too tender to confine  the matter  of  variolus
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, how-
ever, it is very different.
  The  blood vessels  of the  oesophagus come from
those which are in the vicinity.  The nerves are de-
rived from the eighth  pair.  The  lymphatic vessels
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 laminae 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-
cardium before it.   About the ninth dorsal vertebra
it inclines again rather to the left, and somewhat
forward, 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. 
9(>            Form of the Stomach.

  While the oesophagus  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  a; belouging
to the absorbent system. They are sometimes greatly
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 iu its structure.
  It is a large sac, which  is so thin when much iu-
flated that  at first view  it seems membranous, but
upon examination is  found to be composed of seve-
ral laminae 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 auatomists of different nations  to  the  wind
sac of the  musical instrument called the bag-pipe.*
The orifice in which  the oesophagus 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.
  Tho 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 sur-
face are also called the great and small curvatures.
The two  flat  portions  of the surface, or the broad-
sides, 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 verte-
bra; 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
stomach, when placed with  its  small curvature up-
wards, were divided  into two equal parts by a verti-
cal plane  passing lengthways through it, they would
be found on different sides of the plane.
  As the  oesophagus 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;  but it is  more
moveable  at its  other orifice;  for the extremity of
the duodenum, into  which it is continued, is move-
able.
  Vol. II.             13 
 98       External Coat of the Stomach.

   The  stomach is connected^ 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  spleeu 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, aud the oesophagus forms an angle
 with the plane of the stomach.
  The stomach is composed of four  dissimilar lami-
 nae, which may be demonstrated  by a simple pro-
 cess  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 sub-
 stance, called a nervous coat;  and last is  the inter-
 nal 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-
 ma i h in  two delicate laminae, which separate when
 they approach the  stomach, and pass down, one on 
   Muscular and Nervous 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 laminae above mentioned, which includes a trian-
gular space bounded by the stomach  and these two
laminae.   In these triangular spaces,  at each curva-
ture 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 laminae at this place is particularly calculated
to permit the dilatation of the stomach.   When it is
dilated the laminae are in close contact  with its sur-
face, and the blood vessels being in the angle form-
ed by the adhesion of  the two laminae to each other,
are so likewise: when  it contracts,  the blood ves-
sels appear to recede  from  it,  and the  laminae are
then applied to each other.
   Where the peritoneum thus  forms a coat to  the
stomach, 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 muscu-
lar fibres, blood vessels, &c. appear through it.  If it
is carefully dissected from the muscular coat, it ap-
pears somewhat flocculent on that surface which ad-
hered  to the muscular fibres.  It seems to be most
abundantly furnished  with  serous vessels ;  but it
has been asserted  by  Mascagni  and  Soemmering,
that a large proportion of its texture consists of ab-
sorbent vessels.  The cellular substance which con-
nects this to the muscular coat appears no way dif-
ferent from ordinary cellular membrane.
  The Muscular Coat  of the stomach has been de- 
100       Internal Coat of the Stomach.
scribed very differently by respectable anatomists;
some considering it as forming three strata of fibres,
and  others but two.   If the stomach and  a portion
of the oesophagus attached to it be  moderately dis-
tended with air, and the external coat carefully dis-
sected away, many longitudinal fibres will appear on
every part of it, that evidently proceed from the
oesophagus : these fibres are particularly numerous
and strong on the lesser curvature of the stomach.—
Beside the longitudinal fibres there are many that
have a circular direction, and these are  particularly
numerous  towards 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 whole surface, of the stomach, when  the
peritoneal coat is removed, 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 muscu-
lar 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 different
from ordiuary cellular membrane; but if air be insi-
nuated into its texture, by blowing between the mus-
cular 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
effused upon it by secreting organs, and it has been
supposed that there were small glandular bodies ex-
terior 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 laminae 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 hasxbeen
supposed that this  fluid  is furnished by the  small
glandular bodies believed to exist between the coats
of this organ; but, admitting the existence of these 
 103               The Pylorus.

 glands, they are not sufficiently numerous to produce
 so much of* it as is found, and it is therefore  proba-
 ble that this fluid  is discharged from  the orifices of
 exhalent 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  sub-
 stances.*
   As  the muscular coat of the  stomach frequently
 varies its dimensions, the villous and nervous coats,
 which  have no  such  power of  contraction,  cannot
 exactly 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 de-
 pend upon  the  contraction  of  the muscular  fibres,
 and disappear entirely when the stomach is laid open
 and spread out.
   At the lower  orifice is a circular fold, which is
 permanent, aud  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 observation on the Animal Economy, 1786.
  Dr. Edward Stevens.  Inaugural Thesis de Alimentorum Con-
 coctione.  Edinburgh, 1777.
  The Abbe Spalanzani.  Dissertations relative  to Natural His-
tory, &c.  The first  volume of the English translation contains the
 author's  dissertations 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 hi 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

Pylorus.  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
detached, 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 pylorus will then appear like a ridge or narrow
bundle of muscular fibres, which runs across the ex-
tended muscular membrane.  It is evident that when
the parts are replaced so as to form a cyliuder, this
narrow  faciculus will form a ring in it.  Thus ar-
ranged, the circular fibres can readily close the low-
er orifice of the stomach.
  The pylorus separates the stomach from the in-
testine  duodenum; and this separation is marked
exteriorly by a small circular depression, which cor-
responds 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  Supe-
rior   Coronary  or  Gastric,  the  Hepatic, and  the
Splenic.  Beside the first mentioned branch, which
is distributed principally to the neighbourhood of
the cardia and to the  lesser  curvature, the stomach
receives a considerable branch  from the hepatic, 
104         The Intestines in general.
which passes along the right portion of its great cur-
vature, 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 call-
ed  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
arteries have similar names, and pursue correspond-
ing 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, notwithstanding 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 splanch-
nic portions of  the intercostal nerves.

                   section in.

                 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
stomach, which he suspected to be lacteals. See his account of the
absorbents of the stomach. 
           Villous Coat of the Intestines.       1Q5

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 ge-
neral structure.  The coats or laminae 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, their 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 longitudi-
nal fibres:  aud they seldom if ever form complete
circles.
  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
internal  surface, which support  to a certain degree
the permanent circular plaits of the internal  coat,
called valvulse 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  de-
scribers Glandulse 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
Valvulx 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 in-
quiry.  There can be no doubt but that an immense
number of exhaling  aud of absorbent vessels open
upon  it;  but  there  are  many different opinions re-
specting the termination  of one set  of vessels aud
the commencement of the other.
   A very interesting accoutit of the  Villous Coat was
published  in  1744, by  Lieberkuhn, who was con-
sidered by his cotemporaries 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
orifices 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 mu-
cous. He then urged the injection farther, and filled  t'-.e 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 iu breadth.  In each of them is a cavity
 filled with a soft  spongy substance,  which has one
 or more orifices communicating with  the intestines,
 and from which also proceeds a lacteal vessel.   Ou
 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; ajid also by Mr.
John Sheldon, of  London.
  This account of  Lieberkuhn  appears  to have
been  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 iu the investiga-
tion  of it.
   The  late Mr. Hcwson, whose opinion is entitled
to the greatest respect, rejected the idea  of the am-
pullula, and believed that the villi are composed of
networks of  lacteals, as well as arteries and veins;
although  he  added  that " this  is the only circum-
stance  concerning these parts in  which  he should
differ from this very acute observer."*
   Mr.  Sheldon agrees  with  Lieberkuhn : but Mr.
Cruikshanks asserts, that, u in some hundred villi,
he  has  seen  the  lacteals  originate  by radiated
branches, whose  orifices were distinct, on the sur-
face  of the villous." The villous being transparent,
when the intestine was immersed in water, these
branches, filled with chyle, could be  seen passing
into  the lacteal.  Mr. Cruikshanks therefore sup-
poses that Lieberkuhn was  mistaken, and that the
spongy cavity, or ampullula,  was the common cellu-
lar membrane, connecting together all the arteries,
veins, nerves, and lacteals.
   It seems probable, from Mr. Cruikshanks' 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 Mon-
ro, 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 im-
bibing  chyle.             *
   Several of the late French writers adopt the opi-
* See Hewson's Experimental Inquiries, vol. 2, page 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 villous consists
of a fine network  of absorbeut vessels, whose  ori-
fices may be distinctly recognized; and that 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 ap-
peared, 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 fiue 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, whicli
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 near four
times the length of the other.

  * On this subject the student will consult, with advantage, Hew-
son's Experimental Inquiries, vol. 2d; Sheldon's  Histoiy of the
Absorbent System, part 1st ; Cruikshanks on the Anatomy of the
Absorbing Vessels; 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 size and in  exterior  appearance is  very
 abrupt,  and  their communication  is not perfectly
 direct.  A considerable portion  of the Great Intes-
 tine 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 called
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 Jejunwn; 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 Cxcum ; 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
process  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
septum are the stomach, with the commencement 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 por-
tion of the intestine which  passes from the stomach
to the jejunum, and is called Duodenum, is so much
involved 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 laminae of
the mesocolon ;  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 intestine then is invested by the peritoneum
in such manner  as to form mesentery, which  conti-
nues 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 before,  is divided into Jejunum and Ileum :
the jejunum 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 peri-
toneum,  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  laminae of the mesocolon.  In its
 progress  it passes before the aorta and  the vena cava,
 but the  principal branch  of the  vena portarum  is
 before  it.
  The duodenum is  larger in diameter  than  any
 other part of the small intestines, and has a stronger
 muscular coat.   Its general situation admits of great
 dilatation, and it has been called a second stomach.
 Its internal coat is strictly  villous, in the anatomical
 sense of the word ; and its folds, the valvulae conui-
 veutes, begin at a small distance from the pylorus.
 The orifices of many mucous ducts are to be seen on
 its surface.  It is supposed that some of these are
 the terminations 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 depression in the centre, and a foramen in the de-
 pression.  They  are  sometimes very numerous  at
 the upper extremity of this intestine,  and diminish
 gradually towards 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.
 Sometimes 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 always 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 meseute-
 ry.  They agree in  their structure with the general
 description of the small intestines,  but their muscu-
 lar 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 gradually diminish in number,  until they finally
 disappear, in the lower part of the ileum.  The vil-
 lous coat is in  perfection in the jejunum, the villi
 being more conspicuous here 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
laminae of  the  mesentery.   They are called Peyer's
glands,  after the anatomist who first described them;
   Vol. JI.             15 
 114  Distinction between Jejunum and Ileum.

 and are supposed, like the glands of Brunner, to se-
 crete mucus.  If a portion of the jejunum be inverted,
 and moderately distended with air, these bodies  ap-
*pear very distinctly in  it, dispersed at small dis-
 tances from each other.  In  the ileum  tbey  appear
 in small clusters,  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 Wiuslow  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 hi 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 si-
tuation in the abdomen varies considerably at differ-
ent 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.

                  TJie Mesentery
   Is a process of the peritoneum, wiiich is formed
in the manner of a plait or fold, and of course con-
sists of two  laminae.  These laminae proceed from
the back part  of the abdomen, and  are so near to
each other,  that they compose one substantial pro-
cess ; 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 tfie back, and the intestiues are detached  from
it,  is somewhat semicircular 1 that portion of  its
margin  or edge  which corresponds to the diameter
of the semicircle, is connected to the back of the ab-
domen, and  called  the  root of  the mesentery ; the
edge, which  is the  circumference  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 extending fifteen  or eighteen inches,  the
ordinary proportion, is attached to a portion of intes-
tine sometimes  twenty-four feet  in  length.   The
mesentery on account of this great difference between
its diameter and circumference,  has been compared
to  the ruffle of  a shirt sleeve ; its roots being taken
for the plaited edge of the ruffle, and the circumfer-
ence for its loose edge.  But the comparison is not
precisely accurate; for the mesentery is not plaited
at its root, but perfectly smooth, and free from every 
116           Root of the Mesentery.

kind  of fold.  It begins to enlarge towards its cir-
cumference, and enlarges to that degree, that it falls
into plaits or  folds: precisely  such as would exist
in a semicircular piece of membrane 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 circumference, and if por-
tions  like a sextant or quadrant were taken from a
circular  membrane three inches in  diameter,  and
united by their edges to these incisions, so that their
circumference might be continuous with the circum-
ference of the large semicircular piece.  In this case,
the portions  like quadrants  or sextants would  as-
sume  a  folded position like the edge of the mesen-
tery, 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 originally
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 circum-
ference 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. 
       Appearance of the Cxcum 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 laminae
of peritoneum in the  mesentery, and there must be a
small portion of intestine answering to the interstice
between these laminae, which is not  covered  by the
peritoneum.   The blood  vessels, and absorbent  or
lacteals, pass most  commodiously to the intestines
between these laminae ;  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 half 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
derived principally  from the  superior  mesenteric
plexus, are also to be found here.
   The  adipose matter between  the  laminae  of the
mesentery 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 Cxcum and Colon

   Are very differeut 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 Cxcum.
 equal distances  from each other.  The spaces be-
 tween these bands are marked by transverse indenta-
 tions,  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 and 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 Cxcum, 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 Cxcum 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 contact
with  the  surface, aud connected  to  it by  cellular
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  caecum,  situated
anteriorly and internally, is  a small process resem-
bling an earth-worm in form  and size; this is there-
fore called Appendieula  Vermiformis.  It is hollow,
and communicates  with  the  cavity of the caecum at
the place  of junctiou;  and  like the caecum, 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  com-
mence 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 in-
terior coats adhere firmly to them.  Thus  are pro-
duced the  indentations  and cells ; for if the  bands
are divided transversely, the indentations disappear, 
 120             Valve of the Colon.

 and  the  surface of the  intestine  becomes uniform.
 One of these bands is  covered by the mesocolon.
   The circular or transverse fibres of the muscular
 coat of the caecum 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 be 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 des-
 cribed, which separate the incomplete cells from each
 other.  These  ridges differ essentially  from the val-
 vulae conniventes, because all the coats of the intes-
 tine are concerned in  their formation,  whereas  the
 valvulae conniventes are formed  by the villous  coat
 only ; they also project into the cavity  of the intes-
 tine, while the  valvulae are laid on its surface. They
 pass only from one longitudinal band  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

  • Posthius in 1566; Vidus Vidius about 1569 ; Alberti in 1581,
 and Varolius who died in 1575, each lay claims to the discovery of
 it. Bauhin's claims  are in 1579.   Ed. 
        Structure of the Valve of the Colon.    12i

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 coat 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. 11.               If3 
 122         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  laminae of the  omentum,
 which, after  surrounding it, unite again  and  form
mesocolon.  Connected with the exterior  surface of
the colon are many processes,  composed of adipose
 membrane, 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 denomi-
 nated Appendices Epiploicx.

                  The Rectum.
  After  forming the sigmoid flexure,  the colon ter-
 minates ; and the rectum begins opposite to the low-
 er surface of the last lumbar vertebra, and nearly in
 contact with  it: from  this it proceeds downwards," 
Structure of the Rectum.          1S3
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 rec-
tum, because in this course it is  supposed not to in-
cline 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
situation by  the peritoneum,  as the colon is on the
right and left sides  of the abdomen, but more loose-
ly ; and  therefore the  term Mesorectum has  some-
times been applied to that portion of the peritoneum
which is analogous to the mesentery and mesocolon.
The peritoneum 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, aud
not connected 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 mftldle 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
ttiust 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 lower
part of the  internal coat, the veins  are  particularly
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 aud 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  Herophi-
lus, of the school of Alexandria, during the reign of the Ptolemies ;
 and  subsequently by Asellius, of Pavia, in 1622, the knowledge of
 them having been lost for 1900 year.—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
thorax, an important branch, called the rami) ssplanch-
nicus, arises. These splanchnic branches pass through
ihe 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 proceed 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
matter, it is spread over the  intestines  like an apron,
extending 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 laminae, from the concave surface
of the liver to the  lesser curvature of the stomach;
and these laminae, 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 laminae, 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 of the colon :  here the laminae again.
 separate and  inclose 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 laminae,  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 colicura.  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 laminse, 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  incloses a distinct cavity in the abdomen.
 The anterior part of  this sac is composed of two
 laminae, and between these laminae 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
gastro 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 pro-
tect the small intestines,  and lessen the friction con-
sequent upon their motion;  but it has been supposed
'o answer several  other important purposes.*

 *See HalleriElementa Physiologic, vol. VI. page 381.
 Gavard. Traite de Splanchnologie, page 350.
  )r. James Rush's Inquiry into the use of the Omentum. 
CHAPTER 111.
    OF THE LIVER, THE PANCREAS, AND THE SPLEEN.

                   SECTION I.

                  Of the Liver.

  Tins 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 hypo-
chondriac 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 irregular figure, between the circle 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 becomes 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
inclosed 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 obloug, with  two sides,
and an angle continued  along its  whole  length,
  Vol. II.              17 
 130         Li gam cuts of the Liver.

 which extends  from the  transverse fissure to the
 posterior 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 cauda-
 tus.  The largest portion of the bifurcated end forms
 a process 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 Anonymus, its posterior point opposite the
papilla of the lob.  spig. 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 laminae of the  peritoneum pass from the
lower part of the diaphragm at  the back of the ab-
domen to the posterior edge of the liver.  These
processes of the  peritoneum are considered as form-
ing two  ligaments, which  are called the right and
 left  lateral ligament^.   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 diaphragm 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 li-
gament, which in the fcetal  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 incloses  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 laminae of the  peritoneum forms
the suspensory ligament.  Besides these, the perito-
neum 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; arid there is one addition-
al connexion, which  must have a great effect in re-
taining 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 viscous; these veins  of course pass di-
rectly from the substance of the  liver into the cava,
and connect it to that vessel.   As the cava  is sup-
ported by the heart, and also by the diaphragm, it
must  afford a considerable support to the liver.
   When the stomach aud 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 Liver.—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 inclosed 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 laminae 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 like-
 wise 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.
  | Many anatomists deny the existence of this coat; but if one of
 the laminae of the ligaments be carefully peeled off from the sur-
 face of a liver which is slightly affected by putrefaction, it will be
 apparent, although 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 Hepatic
Artery.   The vein which goes to the liver is called
the Vena Portarum, from  the place  at which it en-
ters.   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
called 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 ana-
tomical investigation, that the liver is entirely com-
posed of the ramifications of these vessels and of the
hepatic veins,  with absorbent vessels  and nerves,
which are connected together by cellular membrane.
   It  has  been already observed, that the first great
branch sent  off by the aorta in the abdomen, the
Cceliac, divides into  three  branches, which go  re-
spectively 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 
i&4              Vena Portarum.
off "an artery to the stomach, called the gastrica dex-
tra.  At the great fissure it divides into two branches :
the right  branch, which  supplies 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 artery; and also some  smaller  branches :
it passes under the hepatic duct, and ramifies through
the great  lobe of the  liver.   The left branch is dis-
tributed through the left lobe of the viscous.  It cau
be proved by injection, that the hepatic artery com-
municates 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 Dtict.     135

rior  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 distended
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
umbilical ligament, which  has been already men-
tioned.   This branch is generally in contact with a
branch of the hepatic artery and of the hepatic duct;
and ramifies, like the right branch, into the conti-
guous parts of the liver.
   The Hepatie  or excretory duct originates, by very
small vessels, from the  acini or corpuscles of which
the  liver is  composed,  and into  which the minute
ramifications of the vena portarum and hepatic arte-
ry extend. They accompany these vessels, increas-
ing as they increase, although  the fluid  they con-
tain moves in an opposite  direction; and two large
branches which they ultimately form are situated at
the  portae 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 
13b'    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 considerable  quantity of cellular  substance,
and thus arranged are partially  covered with perito-
neum.   The cellular substance which invests them
continues with them into  the  liver,  and  is more
particularly connected with the vena portarum.  It
is called Glisson's Capsule, and  was supposed to
have some contractile power, which assisted the cir-
culation of the vena portarum ;  but that idea is now
altogether abandoned.   The hepatic  veins, which
receive the blood 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.  Gene-
rally 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 be-
fore  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 porta-
rum or hepatic artery to which they correspond, but
form very large angles with them.  This is proba-
bly 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
semilunar ganglions of the splanchnic nerves. From
these many nerves  proceed, which form  a network
denominated the solar  plexus.   From this plexus
many threads are  sent  off, which form  a network
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 inclosed by Glis- 
Lymphatics.
137
son3s capsule.   They receive some threads from the
stomachic plexus, formed by the par vagum.  Al-
though  the number of nervous  fibres  is very consi-
derable, 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 vessels are injected.
  The deep seated lymphatics are also very nume-
rous in  the  liver, and communicate freely with the
superficial.
  The superficial lymphatics  which are on the upper
surface, proceed through the diaphragm into the
thorax 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 thoracic duct  in the  abdomen,  after passing
through several 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  mode-
rately 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 distin-
guishable from each other.   The section  of  the
biliary duct appears the  thickest; that of the  artery
next; the vena portarum is next in order; and, last
of all, the venae hepaticae.
  The branches of the vena portarum are surrounded
  Vol.  II.              18 
x'tiH    Glandular Substance of the Liver.

by  cellular substance, or Glisson's capsule; and
therefore  adhere less to  the  substance of the liver
than  the branches  of the hepatic veins.  The sec-
tions  of the hepatic ducts have often bile in  them,
and are therefore termed pori biliarii.  The branches
of the artery 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  rough
and irregular, owing to the separation of these acini
from  each other.
  It is asserted by several microscopical observers,
that a minute branch 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 se-
parately 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  mustard seed in which these vessels will not be
found.
  Several anatomists  of the first  character have
likewise 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 hepa-
tic  artery and veins also.   It will likewise pass, in a
retrograde 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 cor-
rect—Ed. 
      Peculiarity of the Liver.—Gall Bladder.  130

chylopoietic viscera, instead of passing to the cava,
enters the liver by the transverse fissure, and takes
on the office of an artery; its coats, on 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 after 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-
der is the uppermost part of it; when he lies on the
  * A case is related by Mr. Abernethy, in the London Philosophi-
cal Transactions, in which  the vena portarum terminated in the
vena cava below the liver, without communicating 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 size.
Some bile was in the gall bladder, but it was less acrid than usual. 
140               Gall Bladder.
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 viscous 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 network; 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
resembles 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
before it enters the liver, is appropriated to the gall
bladder, and  is  therefore denominated  the  cystic
artery.  The veins corresponding to this artery empty
themselves into the vena portarum.*  The  lympha-
tic vessels 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 he-
patic duct from  the  liver, it will  pass to the gall
bladder  almost as  freely as  it passes to the duode
num.

  * It has been justly observed by John Bell, that the veins would
not terminate thus, if bile were secreted by.tke gall bladder. 
    Ductus Communis Choledochus.—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 of 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 frequently 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
      large 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, experience
       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
       circumstance.
         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 al-
       vine discharges is derived from the bile, and they are
       therefore sometimes very green, when the acetous fer-
       mentation takes place in  the contents of the stomach
       and bowels.
         It is asserted by some chemists, that ten parts in
       eleven of the human bile consist of water; that albu-
       minous matter composes about one fortys-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 there 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 vis.
       cid than that which is found in the Hepatic Duct.

                     SECTION II.


                  Of the Pa?icreas.

   Thk 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 spleeu, to which it is  connected by the omentum
and by blood  vessels.  It is not invested by the
peritoneum, but is situated in the space  which exist* 
The Pancreas.              143
between the two laminae of the mesocolon, as they
proceed from the 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 con-
nected 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
pancreas.
  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 cceliac 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 small 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              Pancreatie Duct.
colour, and also in texture ; for it is 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 the
right.
  This duct is situated 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, aud commonly
receives a branch from  the part called the  lesser
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
Ductus Wirsungi, after 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.
  wit is various,  in different subjects, both  in size
ai»4 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 between six and nine ounces; but  it has
varied in different subjects from eleven pounds  to one
ounce.  It is supposed, by many physiologists, that
it frequently 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 ia/the left hypo-

  * In several cases where examination after death evinced that , .
the pancreas had become enlarged and indurated,  particularly at
the right extremity, the principal symptoms were jaundice; great
uneasiness  after taking food; vomiting some time after eating,
but not immediately ; extreme acidity of the matter rejected.
   Vol. II.             19 
 146        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 pel-
vis ; and towards the right side,  beyond the umbi-
licus.
   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 liga-
ment.  Another  process of the same  membrane is
extended to  it from  the great extremity of the sto-
mach.   The peritoneum is  aiso 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
membrane:  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, aud 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 ramify 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, aud 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 network 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 so-
 lar 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 inter-
    esting inquiry.
      Malpighi, who took the lead in researches of this
    nature, before injections  of the blood vessels with
    wax were in use, after investigating  the structure of
    of the spleen by long maceration,  by boiling, by in-
    flation, 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
j   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
    published in Ruysch's works.   One is attached to Epistola Pro-
    blematica Quarta, in the second volume ; and the other to Thesau-
    rus 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 orgau 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. Be La Sone, a French physician, whose obser
vations are published in the Memoirs of the Acade-
my of Sciences for 1754.  After repeating the pro
cesses 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 sub-
stance which was not a mere coagulum, but which,
however, could not be injected.
   He derived  his opinion  from this fact among
others.   After  macerating the spleen  a considerable
time, and injecting water into the vessels until it re
turned colourless, he iujected 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 substance, 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 substance had been composed entirely
of vessels, as was supposed by Ruysch.
   He also examined the spleen after it had been 
 150 Holler and the French Anatomists on the Spleen,

 injected with  wax,  according to the  manner of
 Ruysch, and believed not only that the pulpy mat-
 ter remained uninjected,  but that Ruysch himself,
 in  his  own preparations, removed this substance,
 supposing it to exist for the mere purpose of con-
 necting 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 consisl
 entirely of vessels, but was an additional and dif-
ferent structure.
  He also suggested,  that as the  brain   and  the
muscular fibres were so covered by blood vessels in
the injected preparations  of  Ruysch, that  they ap-
peared to be  composed entirely of vessels,  when in
fact they  consisted of a different substance, so  the
pulpy substance of the spleen was covered or ob-
scured by the blood vessels which passed  through
it, without  constituting its whole substance.
  He confirms the account  of Malpighi respecting
the Whitish Vesicles or Follicles; and states, that
in a majority of cases they are not to be discovered
without  a particular preparation ; but that  they  are
generally made obvious by long maceration of  the
spleen in water.  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
 Desault did not admit the existence of  the transpa-
 rent bodies ; although he believed  that the pulpy
 substance of the spleen consisted of cells which re-
 sembled those of the cavernous bodies of the penis.
   Boyer, whose descriptions of 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 oh
 serves, that the best method of examining them is to
 place a very thin slice of the spleen between the eye
 aud 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 
 15&     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. Hew-
 son,* after stating that the organ was extremely vas-
 cular, so that when injected it appeared  like a mere
 congeries of  vessels, makes this unequivocal asser-
 tion—that there  are  innumerable cells  dispersed
 throughout the whole  substance of it, which are so
 small that they are only to be discovered by the  aid
 of a microscope ; and are to be seen after steeping a
 thin piece of  spleen, the blood vessels of which have
 been minutely 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 a  beautiful  network  on  each cell;  and  that
these cells are sufficiently distinguished  from  the
irregular  interstices  of the  cellular substance, by
their round figure and their great regularity.
  Mr.  Kverard Home, in his papers on the struc-
ture and uses of the spleen, confirms the account of
the vesicles in this organ; and adds, that these vesi-
 cles are occasionally seen in a distended  and  in a
 contracted  state.  That  when  distended  they  are
twice as large as when  contracted, and are  distin-
guishable by the naked  eye; whereas, when con-
tracted, they  require a magnifying  glass  to  be dis-
tinctly  seen.   These observations  appear to have
been made upon quadrupeds.*
  Professor Soemmering appears to unite in the ge-
 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 1808. 
 Questions relating to the Structure of the Spleen, iod

   There  are therefore two questions not perfectly
 decided respecting the spleen.
   First.  Whether its general structure is simply
 vascular,  or whether there is any other structure,
 either cellular or more  substantial, which composes
 its general 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 positive 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 vesi-
 cles, although denied by Ruysch, and neglected by
 the British Anatomists 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  Anatomists, but  also by Hewson and
 and Home among the British.
   The sentiments of physiologists  respecting the
 functions  of the spleen, are more discordant than
 those of anatomists respecting its structure; although
 the subject has been considered by many authors  of
 great ingenuity.*

  * See M.Lieutaud. Elementa Physiologic.
  Hewson's  Experimental Inquiries, vol. III.
  Dr. Rush. Medical Museum, vol. III.
  Haller. Elementa Physiologist, torn. vi. pag. 414
Vol. IT.
20 
CHAPTER IV.
  OF HIE URINARY ORGANS, AND THE GLANDULAi:
                    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 arc 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 Glandulx Renales are  described with the
urinary organs, on account of their contiguity to the
kidneys; and to avoid a derangement of the natural
order of description they are considered first.
  The urethra pertains to the  organs of  generation
as well as to the  urinary organs, and  can be des
cribed most advantageously with them.

                    SECTION I.

             Of the Glandulx Renales.

   These are two small bodies, situated on the  psoas
muscles, one on each side of the spine, behind the pe-
ritoneum 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.         153

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  appro-
priated to them, as the spleen has, but receive small
branches from  several contiguous sources; viz. from
the  arteries of the diaphragm, from the cceliac 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
anatomists since that period.   They exist in a great
number 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. Haller found it in sixteen cases out of nineteen. 
156               The Kidneys.
liar texture, which is uniform, and not granulated
or composed of acini; and they are covered by a thin
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
lumbar  vertebrae.   They rest principally upon the
psoas and  quadratus lumborum muscles, and their
position is oblique; the concave edge presenting in-
wards and forwards, the convex edge backwards,
and the upper extremity approaching nearer  to the
spine than the lower.
  The Right 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  Left 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
glandulae 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 iq
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.
15;
  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 membra-
nous  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 sqon 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 length-
ways, 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 cortical, is
rather more pale in colour and  softer in consistence
i.han  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- 
 ±5&     »         The Kidneys.

 pillae 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 sub-
 stance,  and continue  their aborescent  ramifications
 until they have arrived very near the exterior surface.
 They arc 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 ac-
 curately 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 inclosed 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 papillae 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 pa-
 pilla, but lies loose about the other parts of it. Each
 infundibulum  communicates,  at its apex, with the
 pelvis of the kidney.
   The Pelvis, as has been already mentioned, is  a
 membranous  sac which terminates in the ureter, ex- 
 Cortical and Tubular Portions of the Kidney.  15b

terior to the  kidney.   This  sac generally divides
itself, in the fissure of the kidney, into three large
irregular branches, each of which very soon  termi-
nates in  three or four of the infundibula above de-
scribed.   That portion of the sac which terminates
in the ureter, 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
vascular corticle substance : for Ruysch,  and aftei
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 compres-
sing the papillae.  On  this account the tubes have
been called tubuli uriuiferi.
   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 tabulated  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
 semilunar ganglion, formerly mentioned. They form
 a plexus round the blood vessels, and go with them
 into the gland.
  The kidneys have internal aud external absorbent
 vessels,  although the  external  vessels  are very
 small.  These absorbents  pass through glands in
 the lumbar region to the thoracic duct.
  The proper coat of the kidney is said, by some
 anatomists, to consist of two  laminae; 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 in-
 closes, and may be easily peeled off.   It is reflected
 inwards  at  the fissure  of  the kidney, 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 aud 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 cellular membrane,  to the 
Structure of the Ureters.
iui
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 trian-
gle with it.
   The ureters  are said  to have  three  coats.  The
exterior appears 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 coat 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 irrita-
tion.  The passage of a small  urinary  calculus can
be traced from the pelvis of the kidney to the blad-
der, by  the exquisite pain and the spasmodic affec
tions which it often excites.
Vol. II.
21 
162         Situation of the Bladder.
                   section  in.

              Of the Urinary Bladder.

   The urinary bladder is a large sac, of a muscular
and membranous structure,  which occupies the an-
terior 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 or 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 seeu 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. Pa-
ris, April, 1819.  Colles' Surgical Anatomy, Dublin, 1811, for a
more minute account of this membrane.  En 
Situation of the Bladder.
1(53
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 blad-
der.
   In females the vagina and uterus  are situated be-
tween the bladder and rectum ; so that the connexion
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  rec-
tum, 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 perito-
neum.  It also follows that when the bladder is ex-
tended into the abdomen, and  rises  above the brim
of the pelvis, that part  of it which presents  anterior-
ly, and is in contact with the abdominal muscles, is
without a covering 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 raucous.
  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
thickness, but are thin in some places, and in others
are collected in fasciculi.  They run in  every direc-
tion :  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 exte-
rior.  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 con-
traction, might  prevent the escape of  urine ; this
sentiment,  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 distention, 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 has 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
inferred, that the surface  of this coat was formed by
the epidermis; and some respectable authors have
supposed that they had seen cases  in which portions
of the epidermis of the  bladder had separated and
been  discharged :  but these  appearances are very
equivocal, and  it  is by no means  certain that  an
epidermis exists there.*
   The fasciculi of fibres of the muscular coat occa-
sion this  coat  to  appear very  irregular,  but these
irregularities correspond exactly  with the arrange-
ment of the fibres of the  muscular  coat.
   When the internal coat 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  raucous  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 coagu-
lable matter, in consequence of inflammation, often  forms crusts,
that may be mistaken for  sloughs of  the  integuments,  although
those integuments remain entire. 
166
Mucous of the Bladder.
   Notwithstanding that the sources of this mucous
 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 it 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
 endued with a great degree of sensibility.
  It is evident that the essential parts  iu 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
putrefactive process deposits a substance which appears to be cal
careous. 
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 anteriorly 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 French 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 re-
mark which is very worthy of attention, viz. that it is very subject
to enlargement in old people, forming a tumour which impedes the
discharge 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
    cellular membrane exists  between it and the rectum
    ip males, and the vagina in females.
      The upper  part of the  bladder is connected wTith
    tha 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, aiid  gradually diminishes  as it  ap-
    proaches  the  umbilicus.  In a few instances it  has
    been  found  to be hollow.  In its progress to  the
    umbilicus 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
    hypogastric  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 Abdo-
    men 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 ap-
pear 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 ves-
sels  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
      bladder is very sensible; 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 accompa-
      nies these complaints, the frequent recurrence of pa-
      roxysms, and their duration, are taken into view, there
      seems  reason to believe that none of the painful af-
      fections of the human race exceed those which arise
      from certain diseases of the bladder.  Happily these
      diseases are not very common.
        The function of the kidneys is to secrete 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 cxcrementitiou?
fluid, which contains many substances in solution that
are constantly found in it, and many others that arc
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 nu-
merous.  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 Ani-
mal Chemistry, vol. 2d, page 363; and also Thomp
son'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 Vesiculae
Seminales and the Prostate Gland,  which are si-
tuated  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 up-
per and posterior part  called  Epididymis, and is
connected to parts within the cavity of the abdomen
by a thick cord, which proceeds to it through the ab-
dominal ring.  Each testicle also appears to be con-
tained in a sac, which is suspended by this cord and
covered 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 thinner and more delicate.  The superior de
 licacy of this portion of  the skin is evinced by the
 great irritation produced by the application of sti-
 mulating 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 bulfcs 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 Raphe.
  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
scrotum  be inverted, and  this substance examined
in a strong light, many fibres will appear superad-
ded to the common cellular structure; and sometimes
their colour can  be  distinguished to be red.  It is
not asserted that this will  be uniformly the case;
but certainly 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 6crotum 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
example, 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 chamber
be cool,  a motion of the  scrotum will take place,
almost equal to the peristaltic  movements of the in-
testines.
  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 aud
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 
 1^74 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
 Cremaster Muscle.
  The artery above mentioued is called the Sperma-
 tic.  It commonly arises from the front of the aorta,
 very near its fellow, at a small  distance below the
 cmulgents : 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 hypo-
 gastric, which  passes  to the spermatic cord along
 the vas deferens.
  The  branches  of the spermatic vein are much
 larger than those of the artery: several of them pro-
 ceed 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
 epididymis.  In their course up the cord they rami-
 fy,  and again  unite, so as to form  a  considerable
 plexus, which is  called the  Corpus Pampiniforme,
 and constitutes a considerable part of the volume of
 the spermatic cord.
   As they  proceed  upwards they unite into a few 
lymphatics and Nerves of the Spermatic Cord. I7n

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
numerous, 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 accompany the spermatic  vessels, and  in  all
probability enter the body of the testis and the epi-
didymis.  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 incloses the testicle  as  the pericardium
incloses 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 body
 of the testis up the cord, and is  oval or pyriform.—
 This sac is so reflected from the body of the testicle
 that there is a place on the upper and back part of
 that body at w hich the  blood vessels enter it, with-
 out 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  laid open, the testi-
 cle 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  inclosure in a very firm coat called
 Tunica Albuginea.  Upon the  upper and posterior
 part of it is the protuberant substance, called Epididy-
 ?nis, which is less firm, being exterior to the tunica
 albuginea.   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
inclosed, 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 Epidydimis
  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
fiattish.
  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 oue 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 albugi-
nea 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 epidydimis which is not in
contact with the testicle, and also those surfaces of
the epidydimis 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. II.            23 
178 Tubuli, Septa and Blood vessels of tlte Testicle.

to consist of a  soft pulpy substance of convoluted
threads, of a yellowish  brown colour, which is di-
vided into separate portions by very delicate septa,
attached to the  internal surface of  the tunica albugi-
nea at the posterior part of the testicle.   After ma-
ceration, 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 cau be per-
ceived 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  having been dis-
covered : but at the same time it ought to be observed,"
that these tubes have  not yet been injected from the
blood vessels.   Some ingenious anatomists have in- 
 Blood vessels and Structure of the Testicle, fyc. 179

jected the artery going to the  testicle so successfully,
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 Recta.
These vasa recta unite with  each  other  and form a
network on  the back <5f the testis,  within the tunica
albuginea, which  is called Rete Testis.   From this
network 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  Coni
 Vasculosi.  The number of  these corresponds  with
the number of the  vasa  efferentia, aud  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 epididy-
mis 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 
180         Course of the Vas Deferens.

Vas Deferens, and continues on the back of the tes-
ticle and at the inner  side of  the epididymis to the
spermatic cord.* f
  A small solitary vessel or duct, has been observed
by  Haller, Monro, aud 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
considerable thickness.  The  internal  coat forms a
soft surface, analogous to that of the mucous  mem-
branes :  the external is firm,  and its texture resem-
bles that of cartilage.  Owing  to  the  small  size of
the cavity, the internal coat  has  not  been  separated
from the external.


  * 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 ac-
count of the plate exhibiting this structure, and the explanation of
it, which he published in the Philosophical Transactions of Lon-
don, for 1749. This plate has been  republished by the  second
Monro, in  the Literary  and Physical Essays of Edinburgh, and
also in  his  Inaugural Thesis. Haller  has likewise republished 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 further than this ; but
Monro and Hunter soon  after succeeded so as to fill a  considerable
portion of the body of the testicle with mercury, injected by the vas
deferens.
   f In  Mr. Charles Bell's Anatomical collection in London, there
is a preparation  by his assistant, Mr.  Shaw, in  which the tubuli
testis  are completely injected with quicksilver and unravelled.  I
 saw also in Leyden, one nearly as successfully executed by Profes-
 sor Sandifort.—Ed. 
           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 it  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 vesiculae 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 vesiculae 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 approach each other more rapidly, they pene-
trate  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 Vesiculx Seminales and the Prostate Gland.

   The  Vesiculx  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  Vesiculx Seminales.

 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 vesiculae seminales are laid open by an
 incision, they appear to consist of cells of a conside-
 rable 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 caecum, in a closed extremity.—
From  this tube proceed from  ten to fifteen short
 branches, which are closed iu the same  manner.—
All these tubes are  convoluted so as  to assume the
form of the vesiculae 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
 convoluted, when cut into, will exhibit the  appear-
 ance of cells, as in the present instance.
  This convoluted  tube,  composing the  vesiculae
 seminales,  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 Vesiculx Seminales.     183

time into the vesiculae  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  reser-
voirs of semen, and analogous to the gall bladder in
their functions, until  the late  Mr. J. Hunter pub-
lished his opinion  that  they were not intended to
contain semen, but to secrete  a peculiar mucous sub-
servient to the purposes of generation.
   He states the following facts in support of his  opi-
nion.
   A fluid, very different from semen, is  found after
death in the vesiculae seminales.
   In persons who have lost one testicle, a consider-
able time before death, the vesiculae  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
secretion of the testes, is referred to the testes, and
not to the vesiculae 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-
nut, but 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 chesnut of  this  part of America. 
 184       Prostate Gland.—The Penis.

 The basis of this body is posterior, and its apex
 anterior;  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 vesi-
 culae 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 urethra and neck of the bladder.
Its  consistence is very firm and dense,  resembling
the induration of scirrhus rather more than the ordi-
nary texture of glands.
  This  gland receives small  branches from  the
neighbouring blood vessels, and has  no artery of
considerable 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 can be
 seen in the  substance of the gland,  which perforate
the urethra, and open on the sides of the caput gal-
linaginis 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 in.

                  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, which
 is rounded at one extremity and bifurcated at  the
 other. 
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 to compose 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 underside of the penis,
 to its anterior extremity, invested by this third  body,
 which is therefore called  Corpus Spongiosum Ure-
 thrx.
   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 be-
 tween the  neck of the bladder and the commencement
 of the  corpus spongiosum, which is  not covered by
the corpus spongiosum.  This is called the membra.-
nous part of the urethra.
  The penis, therefore, consists of  two oblong bo-
 dies of a cellular structure, which originate separate-
ly,  but unite together  to form  it; and of the urethra,
which  joins  these  bodies immedately 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 co-
vered 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 the
bones.  Iu 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 vein :
and below  there is a much deeper groove, in which
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
their course;  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  ap-
pears as if formed  by a  number  of laminae and of
filaments, which proceed from one part of the inter-
nal surface of the penis to another, and form irregu-
lar cells.   It has been compared to  the lattice-work
in the interior of bones; and it is suggested by M.
Koux, 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 de-
stroyed by placing the preparation in a corroding
liquor, the wax which remains shows that the mem-
branes 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. Jno. Hunter says on this subject, " That the cells of thte
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 muscular.
  In the horse, the parts composing the cells of the penis appear
evidently muscular to the eye, and in a horse just  killed, they con-
tract upon being stimulated."—Ed. 
188        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 urethrae.  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 occu-
pies  the great groove formed by the corpora caver-
nosa on the lower side of the penis, and continues to
the orifice above mentioned.   At  a small distance
from the prostrate gland the spongy substance which
invests it commences, and continues to its termination.
After this spongy substance has arrived at the termina-
tion of the corpora cavernosa,  it expands and forms
a body of a particular figure which covers the extre-
mities of the corpora cavernosa,  and is denominated
the Glands Penis.
  The  Corpus Spongiosum  begins at the distance
of eight  or  ten lines from the  anterior part of the
prostate.  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  formed by a membrane which has some resem-
blance to the coat of the penis, but is  much thinner,
and by a peculiar spongy substance,  which occu-
pies the space between the internal surface of this
membrane and the external surface of the canal  of
the  urethra.  The membrane  and the spongy sub-
stance, form a coat to the urethra, which, with the
exception of the enlargement  before  mentioned, is
about one line thick.  After this  spongy substance
has   arrived at the termination,  its   coat  adhere?
firmly to the coat of the penis. 
       Structure of the Corpus Spongiosum.    18^

  The  Bulb,  or  first  enlargement  of the corpus
spongiosum, is oblong, and rather oval in form; it
is marked  by a longitudinal depression in the mid-
dle, which is very superficial.  It consists entirely
of the spongy substance above mentioned.
  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 prominent
part is regularly rounded, and is denominated the
Corona Glandis.
   Several small arteries  pass to this spongy struc*
ture.   The pudic artery, as it passes on each  side to
the corpora 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 thai
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 discernable in the human subject; but is
much more distinctly seen in many animals^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 con-
sists 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 extremely sensible, and  has  so  much power of
contraction, that some persons have supposed  mus-
cular fibres to exist in its structure.
  It is differently circumstanced in different parts of
its course.  While  surrounded with  the prostate  it
adheres firmly to that body, seeming to be supported
by it; and here its diameter is larger than it is far-
ther forward.  On the  lower or posterior side of
this  portion of the urethra, is an oblong eminence,
called Verumontanum, or Caput Gallinaginis, which
commences  at the orifice of the urethra,  and conti-
nues throughout the whole portion that is surrounded
by the prostate gland, terminating at the point of that
body.  The posterior extremity  of this tubercle be-
gins abruptly, and soon becomes thick and large;
anteriorly it gradually diminishes to a line, which is
sometimes  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 sur-
faces, 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, arc 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
between  tlris  gland and the  bulb,  without  invest-
ment, 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 blood vessels  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 quicksil
ver injection of the part is  certainly a very satisfac-
tory  proof  of  its  existence.*   Throughout  the
whole extent 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

   * See Med. Chirurg.—Transactions of London--vol. 10th 
 192      Mucous Ducts of the Urethra.

 a bristle, or probe of that size; but some are larger.
 It has not been  observed  that any glandular body
 immediately surrounds them, although they secrete
 the mucous  with which  the urethra is lubricated.—
 On the lower side of the urethra, near the commence-
 ment 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 puri-
form discharge which takes place in gonorrhoea.—
In a natural state they produce the mucous which is
constantly spread over the surface of the urethra, to
 defend 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 considerable distance, if it  cannot proceed the
 whole way, it sometimes  happens that the  instru-
 ment will be discharged by a steady uniform mo-
 tion, 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.
  f Sir Everard Home, whose professional opinions are of great
 weight, has lately described in the Transactions of the Royal
 Society, the appearance of the  lining membrane of the Urethra 
         Contractile Power of the Urethra.     193

   Upon the two crura of the penis, or the beginning
of the corpora cavernosa, are fixed the muscles called
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 poiut 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 bulb of the corpus
spongiosum.!

when viewed through a microscope of great powers.  From this
paper it seems that he is fully convinced of its muscular struc-
ture.—Ed.
  * See description of «« Muscles about the Male Organs of Gene-
ration. Vol. I. Part II. Chap. II.
  f The natural situation of the membranous part of the urethra,
and of the prostate gland, as well as their relative position with
respect to the sphincter ani, rectum, 8cc. can be best studied by a
  Vol. II.              25 
194     Contractile Power of the  Urethra.

   When the accelerator urinse 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 dif-
ficulty but is large enough to admit a bristle.  These
are 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, t


lateral view of the contents of  the pelvis; which  is to be obtained
by removing carefully one of the ossa innominata, and dissecting
the parts which were inclosed 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 ob-
served a fourth.-^-En.
  f There are several fascia  and ligaments about  the perineum
which should be connected with the account of its viscera.  Im-
mediately beneath the skin of the perineum is the Perineal Fascia,
a thin but strong membrane, which extends from  bone to bone, oc-
cupying the space between the anus and the posterior part of the
scrotum.  It is rather better seen in lean subjects than 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 immediately in the pe-
rineum, and drives it into the cellular structure of the scrotum.
  Immediately beneath the perineal fascia are placed the muscles;
when they are removed the bulb of the urethra may  be seen very
advantageously, extending in the middle of the perineum almost to 
Integuments 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 bo-
dy 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 quautity 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

the anus.  It is not loose and pendulous, but is attached by its pel-
vic surface to the triangular ligament of the urethra.   This liga-
ment 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 as the origins 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 lami-
nae, and Cowper's glands are placed between them. About an inch
below  the symphisis pubis a perforation is made in this ligament
for the passage of the membranous part of the urethra.
  Just below the symphisis pubis, between the two laminae of the
triangular ligament, i* 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 fascia of the pel-
vis, see Lessons in Practical Anatomy, by the present editor.—Ed. 
196         Integuments of the Penis.  .

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, forms 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
secreted 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 pro-
duces inflammation on the surface with which it is
in contact, as well as the copious secretion of puri-
form fluid.
   The distribution of 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 haemorrhoidal 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 urethra; 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 comraon 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  which 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 sacral 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 
198       „A erves.—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
pubis  and  ischium, and passing  between the  sym-
phisis pubis and the body of the penis, arrives at the
upper surface or dorsum of the penis, along which  it
continues on the outside of the veins to the glans, in
which it terminates.  In this course it sends off seve-
eral branches,  some of which terminate  in the inte-
guments of the penis.

    After an examination  of the  relative  situation of the
      muscles and blood vessels of the male organs of gene-
      ration, 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 Annota-
      iionum, lib. ii. caput xviii.  Haller has also considered
      it, and stated the opinions of several anatomists, in his
      Elementa Physiologise, 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 narts of the blad-
      der, do not render it probable that uYese parts act like
      a sphincter.  The late J. Hunter, who  paid great at-
      tention to the functions of these organs, was very de-
      cided  in his opinion that the contraction ol the urethra
      produced the effect of a sphincter of the bladder.  He
      has published some very ingenious observations re-
      specting 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 ureth-
      rse was more distinct in the horse than  the man.   In
      the fifth volume of the Lecons d'Anatomie Comparee
      of Cuvier,  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 be filled in a ereat degree with 
General Observations.
199
  rhe ramifications  of  veins, which communicate  with
  each other by such large  and frequent anastomoses,
  that they have a cellular appearance.  A similar struc-
  ture exists in the  horse, camel, bullock, deer, &c. and
  in them all these  communicating branches can be dis-
  tinguished from those which extend the whole length
  of the penis.
The corpus spongiosum urethrse, 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 very 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 ge-
neration, in order to distinguish them from the ute-
rus and ovaries, and their appendages, and also from
the canal of the vagina; which are called the inter-
nal parts.
  The bladder of urine lies above and in contact
with the vagina: the urethra is also intimately con-
nected with it.  The descriptiou 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 prominence 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-
low this.  On each side of this  orifice is a promi- 
            Labia Externa.—Clitoris.        201

nence  continued  from the mons veneris, which is
largest above, and gradually diminishes as it descends.
These prominences have some hair upon them. They
are called the Labia Externa.   Their junction be-
low is denominated  the Fourchette.   The space
between the place of their junction and the anus is
rather more than an inch in extent, and is denomi-
nated 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 less
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 uot 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 erectorcs penis.   The interior  structure of the
Clitoris 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
each other by a septum,  resembling that of the penis.
It is united to the symphisis pubis by a ligament.
  Vol. II.               26 
 20S           Nymphx.—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 Nymphx.
   The Nymphx 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,  lu 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 clito-
 ris.  It is often rather less than the diameter of the
 urethra, and is somewhat protuberant.   The orifices
 of mucous ducts are to be perceived  around it.
   The  orifice of the  urethra  is at  the commence-
 ment of the canal of the vagina.  Immediately with-
 in this  orifice is situated the membrane  denominated
 Hymen.
   The Hymen is an incomplete septum, made by  a 
The  Vagina.
203
fold or duplicature 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 Ca-
runculx Myrtiformes.

                   section n.

                  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 papillae; 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 are 
 204  Corpora Cavernosa.—Sphincter Vaginx.

 smooth. These rugae 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 rugae  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 rugae 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 fol-
licles or ducts,  which occasionally discharge consi-
derable 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 Reteformis,
and  Corpora Cavernosa Vaginx, 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 vaginae muscle, and contract the
diameter of the vagina at the place  where they are
situated.
  The transversus perinei muscles also exist in  tha
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 Tineas, 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 inclosed in a duplicature
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 cham 
 206         Ligaments of the Uterus.

 ber. The posterior surface of this septum is opposed
 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 inclosed by a pro-
 cess of the ligament or septum.   Above them, in the
 upper  edge of the septum, are the Fallopian Tubes,
 which  are ducts that commence at the upper part of
 the uterus on each side, and  proceed in a lateral
 direction for some distance, when they form an angle
 and incline downwards to the ovaries.  These ducts
 are inclosed between  the two laminae 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 Round 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.  These 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
canal is in proportion; so that this  organ is very
thick in proportion to its bulk. 
Structure and Cavity of the Uteru*.    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 differ-
ent indeed from muscle;  but  the uterus occasionally
contracts, with great force, during labour.  It is not
rendered thin by its enlargement during pregnancy,
and the blood vessels in its  texture are greatly en-
larged  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 re-
semblance to those which secrete mucous, and is ge-
nerally of a whitish  colour, abounding  with small
orifices 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 aban-
doned.  It is supposed that the colour of this mem-
brane 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,
w hich  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 oc-
dipied by the  orifice of the canal,  which  passes 
 208    Structure and Cavity of the Uterus.

 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 preg-
 nancy, this canal is gradually converted into a part
 of that cavity.
  The lower extremity  of the  neck of the uterus is
 irregularly 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
 vagina, and is commonly called Os Tincx.   As the
 anterior portion or lip is larger and more tumid than
 the posterior, the vagina extends further beyond the
 os tincae on the posterior part than on the anterior. 
      Fallopian Tubes.—Round Ligaments.   209

               The Fallopian Tubes
  Are two canals, from four to five inches in length,
which proceed between the laminae 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 their pro-
gress. This enlargement is gradual for the first half,
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 laminae
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 consists 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 longitudiual  fibres  of a red  colour to be seen
on it.
              The Round Ligaments,
   Which have already been mentioned, are cords of
  Vol.  II.              27 
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-
 minae 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 of the broad ligament, and  invested
 completely by a  process of the posterior  lamina,
 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 di-
 ameter, and is included between the laminae 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 connected 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 Uterus.
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 are 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  aud  from the hy-
pogastric arteries.
  The spermatic arteries, instead  of passing directly
down to  the abdominal ring, proceed between the
laminae of the broad  ligament, 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
opposide 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 laminae of the broad li-
 gaments, and sends branches to the edge of the uterus,
 which penetrate its texture. The branches which are
 in the texture of the uterus are very small indeed, 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 ob-
serve  a serpentine and peculiarly tortuous 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 important  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.    21S

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 III.

           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 com-
mences 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  Gradual 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 iu 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 vagiua, 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 progress
                  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
seventh month it is  very near the  epigastric region.
   For  the first six months the body of the uterus
  * It has however been asserted that they 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 gra-
dually altered, so as to compose a portion of the sac,
rather of less thickness 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 impor-
tant.
   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 Round 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 diame-
 ter,  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- 
S16   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 occa-
sionally  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
      1805, by Mr. C. Pears.   The subject lived to the  age
      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 never
      enlarged more than they are in the male  subject.—
      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 tincse were found not increased
      beyond their usual size during  infancy.  The cavity
      of the uterus was of the common shape,  but its coats
      were  membranous.   The Fallopian Tubes were per-
      vious.  " The Ovaria were so indistinct that they rather
      showed  the  rudiments which ought to  have formed
      them, than any part of the natural structure."
    Another case, which confirms the  aforesaid sentiment,
      is  related in one of the French periodical publica-
      tions.
        It  has been long known that a race of savages near
      the Cape of  Good Hope were distinguished from the
      generality of their species by a peculiarity  about the
      pudendum.  An account of this structure  has been 
Peculiarities in the Abdomen of the Foetus.  217
      given  with  some precision by Messrs.  Peron  and
      Lesueur, in  a  paper which was read to the National
      Institute 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 cover 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 jMper has not yet been published  by the Institute, but it is
referred  to by M. Cuvier in his Lecous d'Anatomie Compare>,
vol. v. page 124—Messrs.  Peron and Lesueur  were naturalists
who accompanied captain Baudin in his voyage of discovery.
   Vol. II.              28 
218    Descent of the Testicle in the Foetus.

  The Stomach appears to be more curved in the foe-
tus than in the adult.
  The Great Intestine does not extend sufficiently far,
beyond the insertion of the  ileon, to form the caecum
completely.
  The Glandulx  Renales  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 tabulated.
  The Testicles in the foetus are found above the pel-
vis, in the lumbar region, behind the peritoneum, un-
til two months  before  birth.  Thus  situated, their
blood vessels and nerves proceed from sources which
are near them; but the vas deferens, being connect-
ed to the vesiculae seminales by one extremity, is  ne-
cessarily 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
ligament, called Gubernaculum, of a conical or  py-
ramidical 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 extremi-
ty adheres to the testicle, its lower and small extremi-
ty 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.  Thejjeritone-
 uin, which adheres firmly  to the gubernacrrium  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 Foetus.
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 vessels,
&c. which  belong to  the  testicle  are  also  exterior
to it.
   The cavity formed in the scrotum, by this process
of the  peritoneum, necessarily comraunicates 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

  * These interesting circumstances respecting the original situa-
tion of the testicle, and its descent into the scrotum, were discover-
ed and elucidated by Haller, Hunter, Pott, Champer,  and several
other very respectable anatomists and surgeons. There is however
a difference of opinion, between some of them, as to the time when
the testicle leaves the 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 respect; that amongst the Hungarians, for example, the tes-
ticles often remain above the abdominal ring until near the age ol
puberty.
  The student will find an interesting description of the situation of
the testis, and its descent, in the foetus, in the " Observations on
certain parts of the Animal Economy," by John Hunter. 
220             Umbilical Vessels.
than the external iliacs.   Their main trunks are
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  duplicative  of it.
  A vein  also called  the Umbilical, which is much
larger in diameter thau 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  veiu 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 iuto  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 Alls 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 w itli 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 on 
222  Object of the Circulation in the 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 vesi-
cle, 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 pro-
ceeding along the cord to the placenta, continue from it to the ve-
sicle. The artery arises from the mesenteric, and the vein is united
to the  mesenteric branch of the vena portarum. It is probable that
these vessels commonly exsist no longer than the vesicle, viz. about
four months ; but they have been seen by Haller and Chaussier at
the termination of pregnancy. They are called Omfihalo Mesenteric
vessels. 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 Aca-
demical  Annotations  of Albinus, first book, plate i.  figure  xii. ;
and also in  the Icones Embryonum Humanorum of Soemmering,
figure  ii. 
SYSTEM  OF  ANATOMY.
PART IX.
             OF THK 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 carried 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 every
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 tiunks 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 Cava.
  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  functiou  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  discharg-
ed,  like hard tubes.  They submit to great dilata-
tion,  and elongation, when  fluids are  forced into
them, and  return to their  former  dimensions when
the distending cause is withdrawn.  This  elasticity
is particularly 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 con-
traction of the heart.  It also produces the contrac-
tion of the artery ; which takes place as soon as the
action of the heart ceases; and this contraction of
the artery necessarily 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. II.            29 
228
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 of
 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 neces-
 sary 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,
 wrhich 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 laminae,  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 laminae, according
to the  thickness of these laminae.
   The fibres which compose these laminae 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 howrever observes,
that he never could discover the direction  of the mus-
cular fibres.*
   When the  great talents  of Mr.  Hunter as  an

  • Treatise on the Blood, &c. Vol. I. p. 113. Bradford's edition. 
228 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 examine
this subject  himself, by separating the  coats of ar-
teries into  different  laminae ;  and  by viewing  the
edges of the transverse and longitudinal sections of
those vessels.  While thus engaged with this  ques-
tion, he  will read with great advantage what  has
been written 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—System
Vasculaire a Sang Rouge, 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.
German edition. Dr. Jones on the Process employed by nature for
suppressing Haemorrhage, 8cc. 
      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 la-
ceration 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 arte-
ries 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 dis-
tending 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 elastic fibres of
blood vessels, is  a question which is not perhaps
completely decided.

  * This local suspension  of arterial motion by cold, &c, applied
local I ■-, is very difiV.uk to explain ; as the action of the heart and the
elasticity of the arteries appear sufficient to account for the pulsa-
tion of the large arteries. 
 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 coutract
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 circu-
lar ; for it is not certain that there are any longitudi-
nal 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 b}r 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 Artirles.   231

arteries, it has been often 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 branch-
es have been compared to a cone, the basis  of which
is formed  by the  branches,  and  the apex of 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 ; and
when they pass over parts which are subject to  great

  * According to Brussiere the relation of the branches of the aorta
to its trunk is as 25 to 16; Helvetius reckons the orifice of the aorta
in comparison with its branches as 64 to 71. Lassus__Ed. 
 232    General Observations on the Arteries.

 distention or enlargement, as  the cheeks, they often
 meander;  and, therefore,  their  length  may be in-
 creased by straightening, without stretching them.
   Their course apppears 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 branch-
 es 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 anastamosing branches form an
 arch,  or portion of  a circle, from  which  many
 branches gooff.
  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.*

  j Malpighi and Leeuwenhoek declare, that by the aid of a mi-
 croscope, they have seen arteries terminating in the veins.  Haller
 advances formally his own experience in support of his assertion.
 Other anatomists have seen, that in blowing into an artery, the air
passed into the corresponding  veins. Nevertheless Derverney and
some others say, that a particular substance is interposed between
the extremities of these vessels.  Ruysch in his Thesaurus Anato-
micus VI. No. 73, says in  repletione arteriarum, replentur estplu-
rimum quosque venae, et vice versa, ita ut impossibile videatur pre-
cise dicere quomodo res se habeat.  Discours  sur FAnat.—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 ar-
teries.

                   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-sealed, 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 consi-
derable 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. 11.              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 > f 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 bare 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
semilunar 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 Etieme
of Paris 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.
Fabricius Aquapendente claims the discovery for himself in 1574.
Lassus.—Ed . 
         Colour of the Blood in the Veins.     235

to each other; and,  when  raised  up,  they form  a
septum in the cylindrical cavity of the vessel.   The
septum, 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 ef-
fects 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 internal jugulars.—They are placed at unequal
distances 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 IL
a PARTICULAR ACCOUNT OF THE DISTRIBUTION OF THE
                    ARTERIES.

                    SECTION I.

                Of the AORTA,*

    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 ventricle, 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 extends 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.--Eo, 
Situation of the Aorta in the Thorax and 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
situated between the two laminae of the mediastinum,
and in contact with  the left lamina,  through wlrich it
may be seen.   It descends 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
arteries 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 in the lower part
of the pelvis receive some branches from the internal iliac arteries. 
£38 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 ex-
tremities 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  have
been described in the account of  the heart.—See
p. 50.
  The arteries of the head and  of  the upper extre-
mities proceed from  the upper part of the curve in
the following manner.
  A large trunk, called arteria innominata, goes
oft* 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 call-
ed 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

co 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 inno-
minata.

        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 carotips.

        THE  COMMON CAROTIDS

Proceed  towards the head on  each side of the tra-
chea :  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 inter-
nal and external carotids.
  These arteries arc  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 oesophagus, 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 platysnu
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 ani
larynx, and the oesophagus ;  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 absorb-
ent 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 dif-
 ferent  at the commencement from what it is after-
 wards. The internal carotid forms a curve which
 projects outwardly, so as to be exterior to the  ex-
 ternal carotid, while this last proceeds  upwards,
 and rather backwards.

   THE EXTERNAL CAROTID  ARTERY
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 temporal  artery, which may be regarded as the
 continuation of  the external carotid, passes over the
 zygomatic 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 sends off to the back of
the head one which  is called  the  occipital; and,
as it proceeds upwards near the condyle of the lower
jaw,  another which  passes internally, behind the
jaw, to the deep seated parts in that direction.  Af-
ter this, it forms the temporal artery, which supplies
the forehead and central parts  of the cranium.  Be-
sides these larger  branches,  the external carotid
sends off two which  are smaller; one from near the
origin of the sublingual  artery, which is spent prin-
cipally upon the pharynx and fauces, and is  called
the inferior pharyngeal:  and another, while it is
involved with the parotid gland, which goes to the
ear; and is therefore called posterior auris.
  These arteries are distributed  in the following
manner:

        1.  The superior thyroid branch
(Domes 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.
During this course it sends off one branch  to the
parts contiguous to the os hyoides; another  to the
neighbourhood 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 vagnm, either between the os hyoides and thy-
roid cartilage, or the  thyroid and cricoid cartilages,
to the interior muscles of the larynx; and  finally
returns again to terminate  externally.
   While in the thyroid  gland this artery anasto-
moses with the  inferior  thyroid, and  also with its
fellow on the opposite side.
  Vol. II.             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 branches
 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,
 which is called, from its situation, Dorsalis Lingux.
 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  called Sublingual;  while the other branch,
the  Ranina, passes by the side of the genio glossus
 muscle to the apex of the tongue.

     3. The  facial or external maxillary,

Buns obliquely upwards  and  forwards uuder the
ninth pair of nerves, the stylo hyoideus muscle and
the  tendon of the digastric, across the lower jaw and
 cheek, towards the inner corner of the eye, in a ser-
pentine course. Before it crosses the jaw it sends off
 several branches, viz. to the pharynx, the tonsils, the
 inferior maxillary gland and the  parts contiguous to
 it. It also sends a branch towards the chin,  which
 passes between the mylo-hyoideus, the anterior belly
 of the digastric, and the margin of  the lower jaw .
 and some of  its branches continue to the muscles of
 the under lip. This branch is called the Submental.
  This artery then passes round the basis or inferior
 edge of the lower jaw, very near the anterior margin
 of the masseter muscle, and is so superficial that its
 pulsations can be readily perceived. After this turn,
 its  course is obliquely upwards and forwards. Near
 the basis of the jaw it sends off a branch to the mas- 
        Branches of the External Carotid.     243

seter, which anastomoses with small branches from
the temporal; and another which passes superficially
to the under lip aud contiguous parts of the cheeks.
This last is called the Inferior Labial.
   After the artery has passed as high as the teeth iu
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 subsiance  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 aud 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  con-
tinues in  the direction of the main trunk of the fa-
cial artery, by the side of the  nose, which extends up-
wards, sendng 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 arises posteriorly from the
external carotid, opposite to the origin of the sublin-
gual, and  passes upwards to  the basis 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 emerg-
ing from these  muscles, it  runs superficially  upon
the occiput, dividing into branches which extend to
those of the temporal artery.
  The occipital artery sends off branches to the
muscles which are contiguons 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 uuder 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

  The artery next to be described, is sometimes 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 pro-
cess.   It then ascends, in a curved direction, and
terminates behind the ear.
  In this course it sends off  small branches to the
parotid gland, aud 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 cells;
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 se-
 veral 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-examinatiou of these
 bones, and of the zygomatic fossa, &c. when he studies this artery. 
 246      The Internal Maxillary Artery.

 dyloid process of the lower jaw, and extends to the
 bottom of the zygomatic fossa ; van ing 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 ca-
 vity of the tympanum by the glenoid fissure.
   b.  It also sends oft* a small artery called the Less-
 er  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
 Great or Middle Artery  of the Dura Mater, which
 passes in a straight direction to the foramen spinalc,
 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

 (See Vol. I.  page 73.)—He ought to be well acquainted with this
 subject, if he should undertake the management of necrosis of the
 iv/ bones ; or of those fungous tumours, which sometimes originate
 i the antrum maxillare ; as well as of several other complaints. 
         The Internal Maxillary Artery.      217

called  the  Inferior Maxillary.   It passes between
the internal pterygoid muscle and  the bone, and af-
ter giving small branches to the contiguous muscles,
enters the canal in the lower jaw, in company with
the nerve.   This  caual has a very free communica-
tion 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 maxil-
lary foramen, this artery sends  oft' a considerable
branch, which  passes out and anastomoses with the
vessels on the chin, while another branch  passes for-
ward and supplies the canine and incisor teeth and
the bone contiguous 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 tuberosi-
ty of the upper maxillary bone: tbey are called the
exterior 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.
   f. 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 general-
ly small, and often irregular.
   g. An artery,  particularly appropriated to  the
cheek, perforates the  buccinator muscle from within
outwards, and generally terminates on the buccina-
tor, the zygomaticus  major and the muscles of the
lips.  This Artery of the Cheek is very irregular in 
 248      Tlie Internal Maxillary Artery.

 its origin, sometimes arising from the internal maxil-
 lary, sometimes from the deep temporal, and  some-
 times from  the suborbitary,  or from  the alveolar
 artery, to be immediately described.
   h.  The Alveolar  Artery, or  the Artery of the
 Upper Jaw, arises generally from the internal max-
 illary, but sometimes from  one of  its branches.  It
 winds round the tuberosity of the  upper  jaw, and
 sends branches to the buccinator muscle, to the bone
 and  the  gums,  to the antrum highmorianum, and
 some of the molar teeth : and also to the teeth gene-
 rally, 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-
mosing with the small ramifications of the two last
described arteries, and also of the facial artery and
the opthalmic.
  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, aud, 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.  The Pterygo Palatine, or Superior Pharyngeal,
is a small vessel; which sometimes arises from the 
Temporal Artery.            §49
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 Arte-
ry,  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
external  side of the nose; each of these branches
ramifies very minutely upon the Sehneiderian mem-
brane and its process in the different sinuses, and
also in the ethmoidal cells.

            8. The TEMPORAL  ARTERY
Is  considered as the  continuation of  the  external
carotid, 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, ruus  parallel to the
parotid duct, and  below  it.  This branch is spent
   Vol. II.             32 
                   4

 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 typanum
 by the glenoid fissure.
   While this artery is on a line with the zygomia, 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 ramifi-
 cations the course of this blood vessel is peculiarly
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
vagum 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 ca-
vity 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 ca-  /
rotid 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
cavernous sinus on the side  of  the sella  turcica, to
the anterior clinoid process;  here it again forms a
considerable 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. 
 252            Ophthalmic Artery.

   During its course from the place of bifurcation to
 its entrance into the carotid canal, the internal caro-
 tid artery very rarely sends off any branches.  In the
 canal it gives off a small twig which enters the ca-
 vity of the  tympanum;  and sometimes  a  second
 which unites with the Pterygoid branch of the inter-
 nal 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 Arte-
 ries of the Cavernous Sinus or Receptacle.
   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
contiguous nerves, to the dura mater, and the pitui-
tary 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
foramen 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
 optic  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 ob-
 lique direction, and finally passes out of  the orbit
 near  the  internal  angle.  In  this spiral course it
 sends off numerous 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
palpebral, the  levator oculi, obliquus superior, &c.;
but  these parts are often supplied  by the branches
above  mentioned.   The supra orbitar so frequently 
 254    Branches of the Ophthalmic Artery.

 gives off branches to the  muscles that  it has been
 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 ou  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  adductor 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 Sehneiderian 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 the foramina of the cribriform  plate to  the
anterior cells of the ethmoid bone, and  to the ante-
rior part of  the Sehneiderian 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 eyelid, 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 frontal
muscle and the lachrymal sac, it passes down the
side of the nose and anastomoses with the fascial
artery.
   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 vertebral artery.  From
its destination  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 of the fossa Sylvii, which se-
parates the anterior from the middle lobes of the ce-
rebrum.  In its course it divides and subdivides iuto
numerous branches which are spread upon the Pia
Mater, aud 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 which pass
 to the third  ventricle, to the fornix and  septum  lu-
 cid um, 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 anas-
tomose 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 off* the right carotid, and then, assuming the
 name of Right Subclavian, continues in the above
 stated direction. 
            The Left Subclavian Artery.       25^

   The cord of the curve of this artery, and the cord
 of the curve, of the aorta, are not in the same  direc-
 tion, but form an angle with each other.
   The position  of the  left subclavian  is  some-
 what different from that of the right.   Its  origin is
 posterior, and, therefore, the direction of the cord of
 its curve is more immediately lateral.  The curve or
 arch is also smaller.   The situation of the  two sub-
 clavians as relative to the contiguous parts, is, there-
 fore, somewhat different; but each of them  proceeds
 between the anterior and the middle scaleni muscles,
 aud 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 cervi-
 cal vertebrae,  and are inserted  into the first rib, one
 before the other,  so as to leave a considerable space
 between 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 va-
 rious 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 near their
middle;  and, continuing between the cartilages and
the diaphragm, exterior to the peritoneum, termi-
   Vol. II.           33 
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 mamma-
ry artery, or by one of its upper branches, which ac-
companies 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 thy-
roid on the same side, aud  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 vertebra.  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 transverse  process of 
         Thyroid and the Vertebral Arteries.     256

 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 In-
ferior 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
 also take a lateral direction, and are of considerable 
  260   Arteries 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 iuternal 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 Poste-
 rior 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, &c, 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
 thorax.   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
 Internal Carotid. The arrangement here alluded to is very remark-
 able. As the branches which pass off laterally from the single trunk
 of the Basilar rfrtery unite to the Internal Carotids, and the Inter-
nal Carotids are united to each other, there  is an uninterrupted
continuation of artery, which incloses a portion of space of a deter-
mined 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 others. 
          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 Cervical 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 off from the Inferior
 Thyroid, and  the other from one of the branches of
 the 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 lias 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 dissections, with a view to engravings of it, which he pub-
 lished with descriptions, in folio fasciculi.
  These fasciculi have been collected, and, with some other  en-
gravings, form a large volume, entitled icones anatomic^, 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 thf
arteries, by Dr. Barclay of Edinburgh, which I have read with
advantage, as well as a work on the muscles bv the same author. 
262    Branches that go off into the Axilla.

between the scaleni it descends  upon the first anc
second rib into the axilla.  The nerves which were
above, descend with it:  at first they are  necessarily
exterior  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 impor-
tant 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
Tfioraeicx, Mammariae Externx, tyc.
  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, send-
ing 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 internal
 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 common  trunk, which is called the Axillary
 Thoracic.

                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
posta 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 
 264            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-
 flexx.  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
 muscles and the body of the os humeri, at a small
 distance below its head.  It  sends branches to the
 capsular ligament, the periosteum of the os humeri,
 the membranes of the groove for the long head of the
 biceps, the  upper portions of the biceps and coraco
 brachialis, and some contiguous muscles.
  The Posterior Circumflex proceeds  between the
 subscapularis and teres major muscles, and contin-
 ues 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 An-
 terior.
  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 also called Brachial Artery by several writers. 
          Branches of the Humeral Artery.      265

 somewhat spiral.   The situation of the artery is on
 the inside of the biceps muscle, 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-
 dial  artery:  the  other,  which inclines obliquely
 downwards 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 con-
 siderable  branch, which is generally called the Pro-
funda Minor, to the parts contiguous to the internal
 condyle.  The ramifications of  these branches near
 the condyle frequently anastomose with small branch-
 es 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 circumflex. The profunda minor sometimes has a distino*
 and separate origin, lower down than the other
  Vol. 11.              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
 iflnastomotica.
  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 arte-
ry 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
between the supinator radii longus and the  flexor
 carpi radialis, very near to the lower end of the ra-
dius, without changing its direction materially, being
deep seated above and superficial below; it then
alters its course, and, passing under the tendons of
the extensors of the  thumb, to the back part of the 
Course and Ramifications of the Radial Artery. 267

radius, it 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  immediately  contiguous  to the artery.—
Before it turus 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 con-
tinued on  the radial or external side of the thumb,
very near to its extremity.  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 auastoraose 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, aud, 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
 another 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 INTEROSSEAL
                    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 inte-
 rosseal 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 con-
 dyle, 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, aud 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 sepa-
rately.  In this case the posterior soon perforates the
ligament.
  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
downwards towards the wrist, sending branches in
its course to the extensor muscles and tendons.
  This  vessel sometimes divides into two branches.

                The ulnar Artery.

  The  Ulnar artery proceeds among the  muscles
obliquely 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
ligament,  which seems to lie  upon it: from this  it
passes upon the palm of the hand, under the aponeu-
rosis 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 anastomosis  with that important  branch
of the radial artery, which passes up on the inside 
270            Digital Arteries.

of the thumb.  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 metacarpal bone of the  little finger, a
branch which passes between the flexor tendons and
the metacarpal bones, and anastomoses with  the Ar-
cus Profundus.  It then generally sends off a branch
to the inner or ulnar side of the little  finger ;  and af-
terwards 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,
except the inside of the  little finger and the  outside
of the index.
  These branches of the digital arteries are called
Digito Radial aud 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 in.

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 aorta 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 rami-
fications of the  trachea, and the  substance of the
lungs.   They  are not large, aud are very 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 iutercostal
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 Phi-
ladelphia, it was found that, in a very small majority of them, the
ulnar artery formed 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 rami-
fied without 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 cor-
responding side of the index.
  In a few instances also the ulnar artery was still more deficient.
and the radial was proportionally extended. 
 272   Oesophageal 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 Oesophageal 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 oeso-
phagus.   They occur in succession, and sometimes
are five or six  in number.  They also send twigs to
the contiguous parts,  and the  lowermost often  de-
scend to  the stomach.

            TJie 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 ra-
mified 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, aud then proceed  forward,
between  the internal and external  intercostal mus-
 cles, in a superficial but large groove, which is ge-
 nerally to be  found on  the interior margin  of  the 
Intercostal Arteries.
273
lower surface of the rib.*  There is necessarily a
difference in the length of the right and left intercos-
tals,  owing to the position of  the  aorta, which is
rather on the  left of the spine.   In consequence of
this circumstance, the oesophagus 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
proceeds 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, which  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 \\ ith
those of the internal  and external mamillaries, 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 ike 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
 appendages; 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 contigu
 ous 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 comraon  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 Cceliac Artery.    215

 ternal and external branch.   Each  of them  Gene-
 rally sends branches to the cardia or oesophagus, to
 the glandulse 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 stomach, 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 horizon-
 tal, when the body is erect.
  The main trunk of this great artery is so remark-
 ably 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 Co-
 ronary, 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, un-
 til it approaches near to the pylorus.  In this course
 it sends branches to the oesophagus, which frequently
 inosculate with the oesophageal arteries.   It also fur-
 nishes branches to the cardia, which partially sur-
 round 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 stomach, and anastomose with those ramifica-
tions of the splenic artery, called Vasa Brevia.
  It continues on the lesser curvature  between the 
 276              Distribution of

 laminae 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 Portm,
 in which it generally divides into two branches.  In
 this course it very frequently sends oft*  an artery to
 the pylorus, which ramifies about  the  small extre-
 mity 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 sto-
mach, from the pylorus towards the great extremity,
 between the laminae of the anterior portion of the
 omentum,  and  distributes  its ramifications  to both
 sides of the stomach, 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 large. 
                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

              Tlie 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 considera-
 ble size, to the Pancreas.  It also sends one branch
 to the left extremity of the stomach,  which  arises
commonly from the main trunk, but sometimes from
the ramifications, which are soon  to be mentioned.
This branch, which  is called

        The GASTR1CA inferior sinistra,

Is sometimes,  but not often, very  large : Its course
is from left to right.  It is  situated between the
laminae 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 mention-
ed anastomose 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 ra-
 mifications,  four  or five branches pass  to the large
 extremity of the stomach, and ramify there, commu-
 nicating with the  vessels already described.  These
 arteries  have received great attention from physiolo-
 gists, and are denominated Vasa Brevia.

      The SUPERIOR 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 laminae 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 penetrate the spleen.
  j See Vol. II. page 115. 
       and the  Inferior Mesenteric Arteries.    279

 Colica.  From  the  convex side of the curve, the
 superior   mesenteric  seuds off the  important
 branches which pass between the laminae 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 oft* 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 iutestine; 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 injected.*

    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 colon, to which the branches
of the superior mesenteric do not extend.
  This artery arises between the origin of the einul-
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 lie
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 hae-
morrhoidal artery, soon to be  mentioned.

     The EMULGENT or RENAL Arteries
Are the large vessels which pass from the aorta  to
the  kidneys.  They arise between the superior and
inferior mesenteries, one on each side; and proceed
in a direction which is nearly rectangular 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 glandulx 
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
 angle 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 penetrate  the  upper and back  part of the
 tunica albuginea.
    Vol.  II.              36 
£82            Spermatic Arteries.
      The Spermatic Arteries in the Female,
Instead of passing to the abdominal ring, proceed
between  the  laminae 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 ligaments.  Those which are on the op-
posite  sides  of the  uterus,  anastomose  with each
other and with the branches of the hypogastric ar-
teries.
  The lumbar  regions are  supplied  with arteries,
which originate, like the  intercostals, from the pos-
terior part of the aorta between the  thorax and pel-
vis.  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 mus-
cles  of the lumbar regions, and the  abdominal mus-*
cles. 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 arc"
spent upon the contiguous parts, and inosculate with
the arteriae sacrae 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 oft* 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 des-
cends  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
muscles 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  denomination 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 vessel is very
different. The  internal iliac generally divides into
two great branches: theGluteal, which passes through 
 284   Smaller Branches of the Internal Iliac.

 the sacro sciatic notch, and ramifies on the exterior
 and upper part of the os ilium: and the Ischiatic,
 which passes downwards on the outside of  the tu-
 berosity 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 uear  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
                 lleo 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 iliacus interuus
muscle, and is spent on the contiguous parts.
  There are also two or three small arteries called
             Arteria Sacrm 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.   283

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 hemorrhoidal, 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 interims  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 Hemorrhoidal,
 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
 artery is spent upon that part of the rectum, which
 is above and in contact with the sphincter.  It sends
 branches to the prostate  and vesiculae 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 laminae of the broad ligaments
 to the cervix uteri, and penetrates the texture of that
 organ.  The size of this  vessel varies with the va-
 rying 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  maxiraus.  It  is principally  spent
 upon these muscles,  and sends branches  to the con-
 tiguous 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 origin, it commonly sends off a considerable
branch, the  Arteria  Pudica,  which  also  passes
downwards:  it then continues its  course as  above
mentioned, 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.

              The pudica interna,
As has been just mentioned, is often a branch of the
ischiatic artery, but sometimes originates immediate-
ly from the internal iliac.  It proceeds downwards
and inwards, diverging from the ischiatic, and pass-
ing between the two sacro sciatic ligaments to the
interior side of the tuberosity of the ischium, whence
it continues on the inside  of the crus of the os ischi-
um  and  pubis  until it approaches the  symphisis,
when it generally divides into three branches, which
arc spent upon the organs of generation, from which
circumstance the name of this artery is derived.
   One or  more branches  from it  also pass to the
lower part of the rectum  and sphincter ani, and arc
called the Lower Hemorrhoidal 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 be-
tween 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 se-
 cond branch, which passes to the back of each crus,
 and, proceeding along it, parallel to its fellow, ter- 
 §88 External Iliac.—Branches of the External Iliac.

 minates in the glans  penis: in this course it sends
 branches  to the elastic coat, to the integuments, and
 to the prepuce.   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
 distributed through the internal structure of the cor-
 pus 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 Poupart's ligament, it  is imme-
diately  anterior to the  psoas  and  iliacus  internus
muscles 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
downwards 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 oblique.  It passes between the peritoneum
and the abdominal muscles, behind  the spermatic
cord, and  the round ligament 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
 parietes 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
 epigastric,  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 Pouparfs  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
ro 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 internal
 side of the bone; after it has passed the perforation,
 it  is  on the  posterior  side of  it.   After passing
 through.the tendon of the abductors, it is denomina-
 ted 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  gastroc nemii  muscles,  at  the lower
 edge of  the poplitcus muscle, it divides into the an-
terior tibial  and the comraon trunk of the peroneal
 and posterior tibial arteries.
  The femoral artery, soon after emerging  from
Poupart's ligament,  seuds off very small branches to
 the inguinal glands, and other contiguous  parts.  It
 also sends off the

                External Pudics
 Which are two or three small arteries that are gene-
 rally spent upou 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. £91

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  com-
monly is a branch of the profunda,  as above stated.
It passes uuder 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 up-
per and back part  of the thigh, and the parts con-
tiguous to the joint; while the other descends in the
course of the rectus femoris muscle, and some of its
ramifications 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 tro-
chanter.  Its ramifications are expended on the upper
portions  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 abductor muscles, and are expend-
ed 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 off 
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 ramifi-
 cations  extends into the  vastus internus  muscle;
 some of them follow the  tendon of the  adductors,
 and ramify about the internal condyle.
   Several small branches go off from the great artery
 soon after it passes through 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 sev eral 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
arid Inferior External Articulary Arteries.
  The  Superior Internal  artery perforates the teu-
 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 con-
 dyle, and ramifies minutely  on the outer side of the
joint.  Its  superior  ramifications anastomose   with
 those of the descending branch of the external cir-
 cumflex, 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 
Arteries of the Leg.
293
internal head of- the  gastroc nemius 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 gastroc nemius and the plantaris
muscle, and  continues under  the external lateral
and the capsular ligament.   It is distributed on the
external  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  gastroc nemii.  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 descends.
  The branch sent off anteriorly, is called  the An-
terior 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, passes
 down close to the interosseous ligament,  with the ti-
 bialis 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 an-
 kle 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 aud 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 iuferior  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
 outwards 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,
 called Metatarsea, which generally arises about the
middle of the foot,  and passes obliquely outward
 and forward, 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 aud 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
 rather obliquely  inwards,  between the gastroc ne-
 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  Tibiae,
 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 situatiou, 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. 
A     TABLE
fT« fee page 297.]
EXIUBITING THE  DISTRIBUTION OF  THE BRANCHES OF  THE AORTA.
which UK spent upon the substance of the Heart.
  The COMMON  TRUNK
Of the Right Subclavian an
   Right Common Carotid.
At the Curvature,
the side of the trachea, and <
divide at  the upper edge of
the thyroid cartilage, into
•ted to  the  exterior  of  the
head, and the upper parts of
the neck.  It gives off
[The Tongue.  Sublingual Gland.  The Pirn
The inferior PhW, {£ £tfi£SS£? ""•

The Occipital      -     The posterior part of the Cranium externally.
_.  _  4  .   ...   \ The cavity of the Tvinpanum.
The Posterior Auricular J Pam contiglloU510 the external Ear.
                      ("The Superior and Inferior  Maxillary bones.
_.  ,      ...   -ii      ] The Fauces. The  Pterygoid muscles.  The
The Internal Maxillary  ^ PaIale   T|ie Dura Mater.  The Interior of the

                      c The anterior and lateral parts of the Cranium,
                      £  externally.
The Temporal
The Ophthalmic Arterj-, to the Eye and its appendages.
The  Anterior Artery of<T,   ttnterior portion of the Cerebrum.
      the Brain        I
The  Muldle  Artery of I The middle, and part  of the posterior portion
      the Brain        £  of the Cerebrum.
           f,  ..   r Anterior portion of the
The  Internal  Mam-}  parietes of the Thu
  -iary, to the
The Vertebral
The LEFT SCJBCL.iiy.LX.
Each of the Subclavian* is the first portion of the great artery of the
  Upper Extremity of its respective aide.
totlic-<  tcr
■ .;  ■-  -
 x.  TheMammx.
 'helium.  The pos-
      portion of the

Between the  cui
  ture and the great <
  Bifurcation,
                                                                                              The Inferior Thyroid $ Thvroid Gland.   Tra
                                                                                                   to the        t   chea.  (Esophagus.  <
                                                                                              The  Superior Inter-5 Some of the Intercostal  1
                                                                                                   costal, to     ?       Spaces.
                                                                                                                (Muscles,  Glands,  and
                                                                                              The Cervical, to thc<   Nerves, &c.  on the
                                                                                                                C   Neck.
                                                                                                                f Muscles of the Ncct.
                                                                                              TheScapulary,totlie^Do. on the dorsum of
                                                                                                                C  the Scapula


                                                              To the Trachea and substance of the Lungs.
                                                              To the (Esophagus.
                                                              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.
                                                              Glandule Renales.
                                                              The Kidneys.
                                                              The Testicles.  The Ovaries.
                                                              The left portion of the Colon, and the Rectum.            ,
'Lumbas-AHeHa   -""     .--                         Muhcks on the loins and the abdomen.  The spine and the spinal canty.
The kiodlx sacral                                             "Which is spent upon the Sacrum, Coccyx, and Rectum.
 The AXILLARY
s the next portion of
 the artery  of  the
 upper extremity. It
 gives off
The Thoracic and  the External
  Mammary arteries,
To the Pectoral and other mus-
  cles on the anterior part of the
  thorax and shoulders.

    The Scapulary Artery,
To the muscles about the sca-
  pula and the posterior part of
of the Os Humeri.
The Profunda Humeri
At the Elbow it gives off
Branches to the muscles in it:

A recurrent branch.
A branch to the thumb.
To the n.dial side of the index.
To the arcus profundus.
 The cuts

which send off
The arcus sublimit in the palm of
  the hand, which sends *F the
  digital arteries to the sidei of
  the fingers.
K. B.  The lnttroM«l mnd tbe Ulnar
  come off from tbe Humes*!, by a com-
  mon trunk.
The Phrenic Arteries  •
CCELIAC ARTERY
SUPERIOR MESESTER1C
Capsular Arteries  -
EMULOENTS
Spermatiea -
At the great Bifurca* <
  The PRIMITIVE ILIACS,
One of which is divided on each
  side of the Pelvis into
The IUo Lumbar artery t
  The  EXTERNAL ILIAC,
The  first portion of the great
  artery of the lower extremity,
  which passes under Poupart's
  ligament to the thigh, but pre-
ously s
soff
 TThc
0^   te
 £The
The  Sacrum, internally and 1

    Cauda Equina.
  f The Bladder.
to< The Uterus.
  (.The Rectum.

  fThe Muscles on the upper and
to<   interior part of the thigh.
  (The Hip joint, &c.
                       TThe Muscles, kc. on the upper
ischiatic            to<  and the posterior part of the
                       C  thigh.


(Which is often given offCThc Organs of Generation.
    by the Ischiatic.)    j
  The CircumJUxa Ilii,
A small artery, which is
  spent upon the  iliacus
  intemus,  and the con-
  tiguous portions  of the
  abdominal muscles and
  the psoas.

     The Epigastric,
Which is spent upon the
  muscles,  and integu-
  ments of tbe anterior
  part of the abdomen.
  The FEMORAL
      Artery.
The  second portio
  of the great artery  J.
  of the lower extre-
  mity begins 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
  the muscles on the
  thigh.
  Tlit POPLITEAL,
The  third portion of the
  great artery, lies on the
  back of the thigh.
It sends off the articular

  mose with each other,
  and supply the contigu-

It divides into
   Tht .....
Which proceeds down the 1
  terior part of the leg to tne
  top of the foot, from which
  it descends to the sole.  It
  lends off
      Thei
Which is near the fibula on the
  posterior side of the interos-
  seal ligament.  It  is spent
   The rosTXRion tibial,
Which passes down behind the
  tibia and the internal ankle *
  U/the sole of the foot, where
  it divides.  It sends off
A  recurrent branch to anasto-
  mose  with  branches  from
  above.
Branches to the anterior muscles
  of the leg.
Tarsal and  metatarsal branches
  to the upper part of the foot.
The  muscles on the outside of
  the leg.
The ankle and the outside of the
Branches to the muscles.
The  medullary  artery  of the

The internal and the external
  plantar arteries, to the parts
c off from the Popliteal by 
\ 
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 men-
tioned, it anastomoses with the tibialis antica.  The
curvature, thus formed, is called the Arcus Plantaris.
   In this  course, the  External Plantar sends off
several 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 di-
vide, like the digital arteries of the hand, so as  to
send a branch to the side of each toe.  These digi-
tal arteries pass between the muscle  called Trans-
versalis Pedis and the metatarsal bones.   Near the
heads of these bones, each of  them generally sends
off two arteries  that pass upwards between  the in-
terossei muscles and the bones, and anastomose with
the ramifications from the  top of the foot.
   The External Plantar,  soon after sending off the
 the third digital artery, anastomoses with  tbe anterior
 tibial, and then continues to the junction  of the root
 of the great toe with the one next to it, when it divides
 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. 11.              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 al-
ways 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  Veins of the 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. 
 BOO  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 ;* aud a portion of it is so involved
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 lamina 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  sternomastoid  muscle, and  there sends off,
nearly at right  angles, the right subclavian vein.
After it has parted with this vein, it takes the name
of Internal Jugular, and continues to the right fora-
men 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 vertebrae.  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 con-
 siderable.
    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  vertebrae, 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 con-
venience 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 oeso-
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 pro-
 cess of the temporal bone.   The Main Trunk of the
 vertebral vein generally  sends off another external
 branch to the muscles near  the basis of the neck, and
 afterwards  enters the canal with the vertebral arte-
 ry.  While in  this canal, it generally sends off two
 branches through  each of the lateral apertures be-
 tween  the vertebrae.   One  of these branches passes
 backwards to the  muscles of the neck; and the other
 proceeds into the great spinal cavity, and commu-
 nicates 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 si-
nuses  of the brain and of the spinal marrow, as well
as from the muscles of the  neck, into the subclavian
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  exernal  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 common-
 ly 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 de-
 rived 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 general-
 ly larger on one side than the other.* This dilatation
 occupies the fossa at the foramen lacerum.  After
 passing through the aforesaid foramen, the  internal
jugular terminates in the lateral  sinuses of the  dura

  * 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 dis-
 tention.
  It also often appears that the general arrangement of the exteri-
or vein is different on the two sides of the head and neck.
   Vol. IT.             39 
306
The External Jugular.
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. 1. p. 316.)  Into these si-
nuses the  very numerous  veins  of the  rtepia ma
open, proceeding to the sinuses in a direction the-
reverse of that hi  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  arteryj 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
internal jugulars, is continued into the lateral sinuses, and extends
throughoutal 1 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.
  f See the account of this fissure in vol. i. p. 63.
  % The Vasa Vorticosa  of the choroides are one of the excep
tions to this.  See vol. i. p. 356. 
                     \
General Account oj the Great Vein of the Arm. 307

rior  and a posterior, nearly of equal size.   More
frequently  one of them  is  much smaller  than  the
other.   In li majority of cases, the principal external
jugular goes off near the junction of  the internal ju-
gular 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 oil',  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 communicates 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
distributes branches  to the side of the face and to the
forehead.   It also  very  often  sends off, near this
place,  the internal  maxillary vein, which generally
ramifies in such a manner  that its  branches corre-
spond  with those of the  internal  maxillary artery.
Veins which correspond to some of the other branches
of the external carotid artery, the lingual,  occipital,
&c. are often  sent off near this place  by the external
jugular.  They take the names of  the  arteries to
which they correspond,  and commonly accompany
them.

           The SUBCLAVIAN Vein,
Although it originates  differeutly 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- 
308  General Account of the Great Vein of the Arm.

fore or  below it to the axilla.  In  this situation it
gives 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 pec-
toral muscles : it continues superficial on the external
side of tbe 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
superficial branches.   It then continues over the ra-
dius, and inclining to the back of the fore arm, until
it arrives 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 pass-
es 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.    309

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 corre-
spond 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 lather 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 now to 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
stomach and  pylorus,  and  the duodenum.  At the
upper  and posterior edge  of the pancreas, it sends
off a very large branch  to  the spleen, which  often
passes, with slight meanders, along a groove  in the
pancreas.

              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
pancreas; and, finally, either from the main trunk
or its branches before they enter the spleen, the venae
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 of the splenic, the Vena Portarum
takes the name of

     The SUPERIOR MESENTERIC  Vein ;

 Which is larger than the splenic, and passes from 
  312 Superior Mesenteric Vein.—Emulgent Veins.

  behind the pancreas, before the transverse portion of
  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 Portal Ventralis.
 The  part which ramifies  in the liver, Vena Portce
 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 ofi"
 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, crosses
 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 princi-
 pal part enters the body of that gland ; but  some of
 the  branches go 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 external
 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 VENyE vesicales
Have such peculiarities that their ramifications re-
  Vol. II.             40 
314    Ramifications of the External Iliac.

quire particular attention.   They arise from the hy-
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
communicate with the plexus, as above mentioned, and  continue
into the 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
inward 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 sper-
matic 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
organs 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 tho 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-
flexae 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
another superficial  vein, which seems very analo-
gous 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 leg,
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 iuto 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 commu-
nicates  with that vessel, receiving the Intercostal
Veins in its course.
   In this  preparation, the Hepatic  Veins  communi-
cate 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 pulmona-
ry artery arises from the  left and most anterior part
of the  basis of  the  right ventricle, and  proceeds
thence obliquely  backwards, inclining gradually to
the left side for about eighteen or twenty lines, when
  * See note to p. 132, of this volume.
 t 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
and getting as far as it!
and subclavian of the U.w
and joined with the descending; cava. The vessels of the liver entered the heart at the
usual place, in the lower part of the right auricle.
 1820, Case Sd. The trunk formed by the junction of the internal jugular and subclavian
of the left side instead of taking its usual course, passed down vertically, before the leit
branch of the pulmonary artery and belbre the left auricle, then making a sbgnt cur *o
between this auricle and the diaphragm joined with the ascending cava.—Ed
 4 See page 59 of this volume. 
318            Pulmonary Vessels.
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 pulmonary 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 formed 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 origi-
nally the canal that formed  the communication be-
tween  the pulmonary  artery and the  aorta of the
foetus.   Each of the great branches of the pulmo-
nary artery takes a direction backwards, and to its
respective side.  It soon joins  the corresponding
branch of the trachea and the two pulmonary veins,
being  anterior to the  branch of the  trachea, and
above the pulmonary veins.  It is also invested, iu
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 me-
diastinum iu common  with these branches.  It has
beeu observed, that they differ from veins in gene-
ral, 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 consists of medullary matter, which is derived
from the brain  and spinal marrow, and is  inclosed
in a membranous sheath that appears to arise from
the pia  mater.  The smaller  the fibre, the more de-
licate 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 inclosed 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  laminae.   The exterior lamina  combines
with the periosteum, and the interior continues to in-

               * See volume I. page 333. 
320      General Structure of the Nerves.

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, invest-
ing 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, aud 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  Gene-
rale.__Fontana, "Treatise  on  the Poison of the Viper."—Reil,
v Exercitationes Anatomicx."—Scarpa, " Annotationes Academi-
csc."__Prochaska, •' De Structura Nervorum."
  I regret that it has not been in my power to procure Reil, Pro-
chaska, or Scarpa. 
              Plexuses.—Ganglions.          321

parts of the body, as  other  nerves do which arise
immediately from the brain.
   These combinations  are  denominated  Plexuses.
There are several of them in the cavities of the ab-
domen  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 simi-
lar plexus, although not so complex, 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, iu
each of the nerves, which are distributed to any organ.
Thus,  the smaller nerves of the arm that are distri-
buted  to the different  parts, are  not  to he regarded
simply as branches of any  one  of the five nerves
which  are appropriated to the upper extremity, 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 sepa-
rately 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 bv a fine
   Vol. IT.             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, aud  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 gan-
glions:  when they receive and  give off additional
branches, they  are denominated compound  gan-
glions.—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 syraphatic nerve,
throughout its whole extent, forms compound gan-
glions.
  The use of this particular structure does not  ap-
pear to be perfectly known.  It seems, however, cer-
tain, that the different fibres—(of which  the nerves
forming ganglions are composed)—are blended  to-
gether 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 fibrillar, 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.         333
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 tbe cranium and the spine, which is called
Sub-Occipital.  Twenty-nine  or thirty pair  pass
through the foramina of the spine : they are denomi-
nated  Cervical,  Dorsal,  Lumbar and Sacral, from
the bones with which they are respectively connect-
ed. There  are seven pair of Cervical nerves, twelve
Dorsal, five Lumbar, and five or six Sacral—amount-
ing, 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 gene-
rally are expressive of the functions of the different
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
*he Nervous System.  Plate xviii.
  f See London Philosophical Transactions, for 1795, Part I. 
324             Olfactory Nerves.

uuder 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
galli.   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 gan-
glion.
   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 Sehneiderian
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 sur-
face of the ethmoid bone.*

     THE SECOND PAIR, OR THE OPTIC NERVES,

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
matter, inclosed in a coat derived from the pia mater,
and has not tbe 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. Page 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 infun-
dibulum  and the corpora albicantia of  Willis  are
situated.*  Anterior to this  substance they come in
contact 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. p. §23. 
326     Fourth and Fifth Pair of Nerves.

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

           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
behind  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 tbe brain.   They proceed along the
edge of  the tentorium which they  perforate, and
passing through the upper part of  the cavernous si-
nus, enter the orbit by the foramina  lacera.  They
are exclusively appropriated to the Superior Oblique
or Trochlearis 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 generally surrounded by soft adipose matter.
  f See Vol. I. page 356.
  % See Volume I. Page 33$. 
First Branch of the Fifth Pair.     327
lion 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 ex-
pansion, but they appear  to  be  more numerous*
Round the circumference of the expansion is a sub-
stance of a brownish colour, into which the fibres
enter.   This  is  the  Semilunar  Ganglion, or the
Glangion 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 Supra Orbitar, the Nasal and the Lachrymal.
  The  Frontal  or Supra-Orbitar branch proceeds
forward in the upper part of the orbit, exterior to
the membrance 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
upwards on the head.  Some are  distributed to the 
328     Second Branch of the Fifth Pair.

anterior 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 ex-
treme 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 inter-
nal canthus of the eye, and sends twigs to the la-
chrymal 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 lotundum 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 orbi-
tar canal.  At the same place it  sends  downwards
two branches which unite together almost immediate^
ly after their origin, and, as  soon as they have uni-
ted, enlarge into a ganglion.*  This ganglion is call-
ed the Spheno-Palatine. It is rather of a triangular
figure, and lies very near the spheno-palatine fora-
men.   It  gives off a posterior branch, which passes
through the pterygoid  foramen to  the cavity of the
cranium :  some branches which proceed through the
sphenopalatine foramen to the imse, and are called
the Spheno-Palatine or Lateral Nasal Nerves: and
an inferior branch, that proceeds  through the poste-
rior palatine canal, and is called the Palatine Nerve.
  The small 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 Nerve, pro-
ceeds backwards and perforates the aponeurosis of

  * Sometimes a single branch passes downwards instead of two ;
hut it forms a ganglion in the same place.
  Vol. II.             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, which 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 al-
so proceed from these nerves to the posterior part of
the gums and the 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 tbe  roots of the incisor, canine, and
small molar teeth, each in its proper canal.  These
dental branches sometimes pass in the antrum maxil-
lare 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 under 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 Spheuoides, and
proceeds through  it.   After leaving this canal, it
passes 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
foramen, or  Hiatus Fallopii, on the anterior side of
the petrous portion of the. temporal bone, and conti-
nues, 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  ca-
nal.*  The other branch of the pterygoid nerve pro-
ceeds to the Foramen Caroticum, and passes through
it, with a twig of the sixth pair, to join the first cer-
vical ganglion of the Intercostal .A ewe.
   T heSpheno Palatine, or Lateral Nasal Nerves, con-
sist of several branches which pass from the spheno-
palatine ganglion through  the  spheno palatine fora-
men, into the nose.   Some of them are distributed
to that part of the pituitary membrane, which is above
the upper meatus, and others to the part which is im-
mediately 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.f
   The Palatine Branch proceeds, through the canal
formed by  the upper maxillary and palate bones, to
the  roof of the  mouth and tiie soft palate.  Soou 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

   • 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
 tympani.
   f  The  curious distribution of this nerve appears to have been
 known to the late John Hunter, and also to Cotunnius ; but it is mi-
 nutely described by Scarpa, and is delineated by Soemmering in his
 plate of the nose —See " Observations on certain parts of the Ani-
 mal Economy," by J. Hunter, page 219,—and also Scarpa " De Or-
 gano Olfactus." In this last are some interesting observations rela-
 tive to the ducts of Steno. 
362      Third Branch of the Fifth Pair.
 part of the membrane of the nose which covers the
 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 zygoma-
 tic 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 lower
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
 hyoideus 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 ninth pair of nerves,  and it sends  twigs to the 
The Sixth Pair of Nerves.         333
membrane of the mouth and gums, and the contigu-
ous 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 anterior foramen, it is spent upon the
muscles  and integuments  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 pro-
ceed through the  dura mater on  the  inside of the
fifth pair, and appear to pass through the cavernous
siuuses, but are inclosed in sheaths of cellular mem-
brane while they  are  in  those sinuses.   When in
this situation 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 uuite  themselves
to the  upper extremity of the upper cervical gang-
lion of the  intercostal nerve.
  The sixth pair afterwards  pass into the orbit of
the eye, each through the foramen lacerum of its re- 
 334 Composition of the Seventh Pair.—Portio Dura-

 spective side, and is spent upon the Rectus Externus
 or Abductor muscle of the eye.

          THE SEVENTH PAIR OF NfRVES
 Comprises two distinct cords which have very  dif-
 ferent  destinations ;  and have, therefore, been con-
 sidered as different nerves, by  several anatomists.
 One of these cords is  appropriated to the  interior i)f
 the  ear, and  is the proper Auditory Nerve.  The
 other is principally spent upon the face, and, there-
 fore, has been called the Facial.  They have, how-
 ever, more frequently been denominated the Seventh
 Pair,  and distinguished from  each other,  in conse-
 quence 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, vvhile  the Portio  Dura  is seen
to rise  from  the union of the  pons Varolii with  the
medulla oblongata  and  the crura Cerebelli.  The
 Portia 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  com-
 posed,  proceeds from its origin, to the Meatus Au-
 ditorius Internus of the temporal bone; aud the Por-
 tio  Mollis divides  into fasciculi, which proceed to
 the  different parts of the organ  of  hearing, in  the
 manner described in the account of the ear.*
  The Portia Dura  enters an orifice at  the upper
 and anterior part of the end or bottom  of the Meatus
* See volume I, page 336, 
        Chorda Tympani.—Pes Anserinus.    335

Auditorius Internus.   This orifice is the commence-
ment of a canal, which has  been called the Aqueduct
of Fallopius, 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 stylomastoid 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  al-
most at the end  of the canal, it sends off, in  a retro-
grade direction, a small branch which proceeds into
the cavity of the  tympanum, (entering  it by a fora-
men near  the base of  the  pyramid) and crosses the
upper part of it, near the raembrana  tympani, be-
tween the  long processes of the  Malleus and Incus.
This twig is the  Chorda Tympani: it proceeds from
the cavity, by a fissure on  the outside of the Eusta-
chian tube, to join the  lingual  branch of the fifth
pair, as has been already mentioned.*
   The Portia 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 Economy, 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 An-
 serinus.
   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-
 orbitar 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 ma-
 lar bone, &c. Some large branches pass transversely.
 They cross the masseter  muscle, and divide into ra-
 mifications 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 Vagum,
 on account of their very extensive  distribution.

 * A most minute and laborious description of the nerves of the
face was published by the celebrated Meckel, in the seventh volume
of Memoirs of the Royal Academy of Sciences of Berlin, for the year
1751, accompanied with a plate, exhibiting the side of the head, of
three times the natural size. This is republished in the Collection
Academique: Partie Etrangere.—Tom. viiij. 
    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
originates in the great canal of the spine, and, pass-
ing 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
termination of the  hyoglossus  muscle$ and after
   Vol. II.              43 
 338  Glosso-Pharyngeal Nerve.—Par Vagum.

 sending branches to the lingualis, and the various
 muscles inserted into the tongue, terminates in small
 ramifications that are spent upon the sides and mid-
 dle of  the root of the tongue, and upon the large
 papillae.

                 THE PAR VARUM
 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 aud  on the out-
 side of the  carotid,  and are contained in the same
 sheath of cellular membrane which incloses that ar-
 tery and the internal jugular  vein.  Each of these
 nerves,  soon after it leaves the cranium, gives a twig
 to the glosso-pharyngeal; that soou after it sends off
 a branch called the Pharyngeal, which unites to one
 from the accessory nerve, and  to  one or more from
 the glosso-pharyngeal, 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 Branch of the Par Vagum. 339

  The External Branch  sends twigs to  the pha-
rynx, 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 anterior 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 Recurrent 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
 recurrents 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 trom the inter-
 costal  and from the recurrent, and form  a plexus
 upon  the  anterior part of  the  vessels going to the
 lungs.  This Anterior Plexus, after sending off some
 minute branches to the cardiac nerves and the peri-
 cardium, 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 oesophagus.
   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 aie 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 of  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, tyc.  341

upon  the oesophagus; the left nerve being situated
anteriorly, and the right posteriorly.  Each of these
nerves forms a plexus so as nearly to surround the
oesophagus, as they descend on it; but the network is
thickest on the posterior side.  They pass through
the diaphragm with the  oesophagus, aud 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, aud  sometimes about the
fourth.  It enters  the cavity of the cranium through
the foramen magnum,  and proceeds upwards and
outwards, so as to join the eighth pair of nerves at
some distance from its origin, and in this course  it
receives filaments  from  the medulla 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 pass-
 ing 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 la-
      ryngeal 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  pyrami-
dalia  and the corpora olivaria.  Three or  four fa-
sciculi, 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 cel-
lular membrane, to the eighth pair,  and to the first
ganglion  of  the sympathetic, soon  after it passes
from  the  occipital  bone.  It is  either connected to
the sub-occipital nerve by  a small ramification, or it 
Ninth and Tenth Pair of Nerves.     343
joins a branch which proceeds from the sub-occipital
to the cervical, and bends round the transverse pro-
cess of  the  atlas.   It passes between the internal
carotid  artery  and the internal jugular  vein, and
crosses  the external carotid at the origin of the occi-
pital artery.   At this place it generally sends down-
wards a large branch which is called the Descendens
Noni.  Passing forwards, 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 hyoglossus mus-
cle, begin to enter in the substance of the tongue, be-
tween the genio-glossus 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 CERVICAL NERVES.
   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 medul-
la 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 hypo-
 glossal, above.  It also sends  filaments to the upper
 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 se-
parate  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 sym-
pathetic^ and a considerable ramification to the third
cervical nerve.  It also sends off some twigs to the
sterno-mastoid muscle, aud  others to join the acces-
sory nerve.  Some of  its  small  ramifications  pass
down upon the external jugular vein,  and others
unite with  the descending 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 in-
teguments  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.f—The posterior branch of this nerve is spent
upon the extensor  muscles of the head and neck.

           THE THIRD CERVICAL NERVE
Sends down, from its Anterior Branch, the principal
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 shoulder
and lower  part of the neck.   A  small Posterior
Branch is  spent upon the muscles of the back of the
neck.

  ■j- 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 TliE 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 their for-
mation ; 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 anticus;
it descends into the thorax within the anterior end
of the first rib, between the subclavian vein  and the
artery.  It sometimes  receives a twig from  the fifth
cervical 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
rie;ht proreeding  in a more perpendicular direction.
When they arrive at the diaphragm, they divide into
many ramifications, which  have a radiated arrange-
ment, and terminate on the fibres of that muscle, both
on the upper and lower surface.   Some fibres from
each nerve are continued downward, and communi-
cate in the  abdomen with fibres from the intercostal.

THE FOURTH, FIFTH, SIXTH, AND SEVENTH CERVICAL
                    NERVES,
May be comprised  in  one description.   They pass
off successively from the Medulla Spinalis, between
the. vertebrae, 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
intercostal nerve, and a few small branches  to  some
of the contiguous muscles.  They are arranged and
combined so as to form the network, now to be de-
scribed,  which is called the Brachial or Axillary
Plexus; and,  in the formation of this plexus,  they
are joined by the first dorsal nerve.

          The BRACHIAL PLEXUS

Extends from the lower part of the side of the neck,
into  the arm-pit.   It commences in the followiug
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  down-
wards, divides also  into two branches, one of which
unites with the uppermost branch that proceeds from
the uniou of the fourth and  fif h,  and the other with
the lowermost, aud  they all proceed downwards.
  The seventh cervical is joined by the first dorsal,
which proceeds upwards, aud 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
downwards, they divide, and their branches again
unite.  The axillary  artery, which passes in the
same direction,  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 Cuta-
 neous; Hie  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
becomes more superficial; and continuing among the
tendons of the  flexors  of the fingers, it gives off a
branch  which is principally spent upon the integu-
ments of the palm of the hand.   This great nerve
passes with the tendons under the annular ligament;
and immediately 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 subdivide so as to send a ramification to
each side  of the thumb, of the index, and of the mid-
dle 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 branch-
es 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 Superficial divides into two principal branch-
es, an external and an internal.  The external pass-
es under the aponeurosis palmaris : and,  after send-
ing a branch to combine with one from the median,
and some twigs to tbe contiguous muscles, it  subdi-
vides 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 fiuger.
  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
muscles.
  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 which terminate in
the integuments.   It then proceeds downwards  be-
tween the supinator radii longus and the brachialis
interuus.  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
radialis longior; it soon after divides into 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 aud 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 back-
wards 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. 
353
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 medulla spinalis
by two fasciculi of fibres—one from each of its late-
teral 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 anterior 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
tbe ramifications  tp the sympathetic; and also a 
     General Account of the Lumbar Nerves.   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, aud combines there with a branch of the cuta-
neous nerve, being distributed to the internal and pos-
terior 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 L UMBAR Nerves.
  There are five  pair of these nerves.   The first of
them passes off between the first and  second of  the
lumbar  vertebrae, 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 canda equina ; the  other
four pair are formed by the canda equina.
  They commence by anterior and posterior fascicu-
li, which are united at a ganglion.   From this gan-
glion, anterior and posterior branches go offj which
are very different in size, the anterior being the lar-
gest.
  The posterior branches are distributed to the mus-
cles of the  back.   The anterior send 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. II.            45 
354    Lumbar Nerves.—Lumbar Plexus.

            THE FIRST LUMBAR NEUVE
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 oft' 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 iu
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 TA/r^lumbar nerve.  From
this union of the second and third nerves,  a branch
called the Cutaneous 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 are sent off the Obturator Nerve, which passes
through the aperture in the membrane that closes the
foramen thyroideum ; the CruralNerve, 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 accession
from above, descends into the pelvis, and unites with
the sacral nerves.

  • The external spermatic often comes off from the first lumbal
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 Cutaneous  Medius, the  Obturator, and the
Crural J\erve.
  The Cutaneous Medius which  arises  from the
union of  the second and third nerves, as has been
already observed, proceeds downwards, and frequent-
ly adheres to the crural nerve, for  a short distance,
near Poupart's ligament, but soon leaves it, and de-
scends on the inside of the thigh, supplying the in-
teguments 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 out-
side 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  Cutaneous.—They are
distinguished by the terms Cutaneous 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, the sartorius,
and the gracilis.  Among these nerves there  is one,
called the  Saphenus, 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 integuments 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.f  The uppermost of the anterior branches

  * The sixth pair, when they exist, proceed in a groove in the os
coccygis.
  f The ganglions of the fourth and fifth nerves are extremely
small and not so hear the foramina as those of the others. 
        Sciatic Plexus.—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
formation 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
compose 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
lowermost of  these a branch descends on the thigh.
   The Pudic Nerve, which  is  appropriated to the
 organs 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,  aud divides into
 two  branches—an  inferior  and a  superior.  The
 inferior passes between the  erector penis  and the
 accelerator urinae 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 
 358    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 sending branches  in  its course to the
 integuments generally, and  to the prepuce.
  In females,  the  Inferior Pudic Nerve proceeds
 along the external labia pudendi to the mons veneris,
 sending 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  uerves unite in the sciatic plexus to
form the great nerve of the  lower 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 exter-
nal.   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 ouiy 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. Iu 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 muscles  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, contiuues down the thigh,  between
the  tendons of the flexors, behind the  great blood
vessels, and of course exterior to them. 
 360      Distribution of the 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 gastroc nemii,
 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
 Artery ; 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 Tibix, or Saphena  Externa,  which
 parses down behind the gastroc nemii, and gradual-
 ly inclines externally,  so that it  is situated  on the
 external  edge of the tendo  Achillis, soon after the
 commencement of that tendon, and  proceeds behind
 the external ankle, near the outer side of the foot, to
 the smaller toes; distributing branches to the conti-
 guous parts.   In its course on the back of the le^,
 it sends off a branch which  unites  with  one of  the
 superficial ramifications of the fibular nerve, and  de-
 scends 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 network 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 aud External Plan-
tar Nerves.
  The Internal Plantar Nerve proceeds  forwards,
 along side of the tendon of the long flexor  muscle of
tbe 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 ra-
mifications.
  The External Plantar Nerve proceeds with  the
external plantar artery towards the external 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 corre-
sponding sides of these toes.   The third branch pro-
ceeds more deeply in  the foot, from the  external to-
wards 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 ramifi-
cations of the pterygoid branch of  the upper maxil-
lary 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
form  a network 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 Superior Cervical Ganglion  of the  Sym-
  Vol. II.              46 
362     First Ganglion, and other Cervical

pathetic Nerve, and from  it the nerve descends, be
hind the Par Vagum, 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 caro-
tid artery, at its bifurcation, and are joined by twigs
of the PortioDura and the Glossa-Pharyngeal nerves.
From  these united twigs proceed very small ramifi-
cations, which accompany several branches  of the
external carotid artery, aud some of them pass down
with the Common Carotid.
  This superior ganglion also  furnishes small twigs
which accompany the Glosso-Pharyngeal to 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  oesophagus, 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 vertebrae 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 Gang-
lion.   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
vagum 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  Plexus, or Plex-
uses, which is situated about 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  down-
wards on the carotid artery.  After passing beyond
the ganglion, 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  Car
diac Plexus, to which it contributes largely.
  The third cardiac nerve of the right side is called
the Inferior, or the Small Cardiac Nerve.  It origi-
nates 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 coronary
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 branch-
es 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.  Rei-Q 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 cardiac 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 proceed  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  ar-
ranged around them that, by some anatomists, they
have been said to form plexuses, which  have been
denominated Coronary.
   The Sympathetic Nerve, as has beeu 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 direction,
along the spine, exterior to the pleura, to  the inferior
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  medulla 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, and 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 network, 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
vertebrae, 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  sepa-
rately into the cavity of the abdomen :  it then gene-
rally 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
coeliac 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 irregu-
lar  forms, and very different from each other in size,
as well as form.  Those  formed by the splanchnic
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 network 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 cceliai
*ind 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 networks of nerves ex-
tend upon the great branches of the  artery  to the or-
gans 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 network,  denominated   the  Hepatic
Plexus, extends upon the Hepatic Artery, and from it
to the Vena Portarum ; and accompanies those ves-
sels 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
network, which extends *o 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 laminae of the mesentery.  In this course it sends
branches, with the arteria colica dextra, to the trans-
verse portion of the colon.   Between the laminae of
the mesentery, it  sends ramifications with all  the
branches of the artery, to the small  intestines gene- 
Abdominal Viscera.
369
rally;  to the coecum,  and the right  portion of the
colon; as well as to the mesenteric glands.
  From the lower part of the solar plexus a network
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 raraifi*
cations combine with those of the hypogastric plexus.
  The, Emulgent Artery is attended by nerves, which
are arranged like a network 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 sub-
stance 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 its inferior part, some new fibres,
which, after joining some others from one of the lum-
bar 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 fol-
lowed 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 network
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
6ide by many ramifications  from the third lumbar
nerves, which  thus form a  plexus  of  considerable
extent, that sends nerves to the bladder, rectum, and
vesiculae  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.
   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 vertebrse  and  tbe  psoas muscle, and  a
 ganglion is generally formed at the place where they
join the nerve.
   In  its descent on the  lumbar vertebrae, the  Sym-
 pathetic sends off several nerves that unite  to the
 network 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 in-
 ner side of the  great foramina: here it  also forms gang-
 lions, and communicates with the sacral nerves, and
 likewise with  the hypogastric plexus.  It terminates
 on the os coccygis, where its minute  fibres join those
 of the  opposite side.

  * Although the testicle receives nerves which are derived from
 the Sympathetic,  the penis and other external parts of the organs
 of generation do not: the nerves which accompany the pudic arterv
 being derived from those which unite to form the great Sciatic. 
SYSTEM  OF  ANATOMY.

             PART XL
           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 intestines ;
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 re-
maining  absorbents, or  those of the  Right Upper
Extremity, and the Right Side of the Head, 8£c. also
form a trunk, which terminates  in the corresponding
part of the Right Subclavian Vein.
  The absorbent vessels of  the middle  size, which

  * Discovered at Leyden in  1650, by Olaus Rudbeek, and at Co-
penhagen in 1651, by Bartholine.—Ed. 
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 yalves 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, originat-
ing from opposite sides of the vessel.
  The absorbents are generally somewhat dilated on
the side of the valve which is next to their termina-
tion,  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 liues
 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 senti-
 ment respecting the structure of these organs, j

  * See his work on the Structure and Physiology of Fishes, p. 34.
  f Mr. Abernethy states, that the mesenteric gland of the Whale
consists of large spherical bags, into which a number of the lacteals
open. Numerous blood vessels are ramified on the surfaces of these 
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 absorb-
ents which accompany the blood vessels.

cysts; 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 I.

    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 network 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
network, 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 ou
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, incliue 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 ab-
sorbents proceed also from  the buttock and lower
part of  the back, from the lower  part of the abdo-
men, the perineum, 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 artery.  The last, often passes through  an
aperture in the interosseal ligament, about one third
of the distance from the ankle to the knee, and ac-
companies the fibular artery, while the anterior tibial
artery is joined 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
intimately 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, vvhile 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 tbem.   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  ves-
sels 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
vessels, aud 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,
aud 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, fyc.

of the great branches, which unite to form the thora-
cic 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 epidi-
dymis,  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 accom-
pany the absorbents of  the testicle to the lumbar
glands;  but those which are superficial  enter  the
upper 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  ibsorbents
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  ab-
dominal ring with  the round ligament; and others
proceed to the inguiual glands. 
     Absorbents of the Pelvis and the Kidneys.  381

                   SECTION  n.

   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 hypogastric,  or
some of the contiguous plexuses.
   The Absorbents of the Womb are extremely nume-
rous; 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 sper-
matic 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 through 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
filled 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 th«
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 structure
of the intestines, and originated from their external
surface, as they do in other  parts  of the abdomen ;
while the  principal part of them are appropriated 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 laminae of the mesentery.
  Branches of these  different absorbeuts are fre-
quently 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
account 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 laminae of
the mesentery to  glands  which are also seated  be-
tween those laminae.   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 nume-
rous in that part  of the  meseutery which is nearest
to the spine.  They are  almost always at some dis-
tance from  the intestines.  They appear to be pre-
cisely like the absorbent  glands, in other places.
  These absorbent vessels, in their course frequent-
ly divide into branches ;  which sometimes go to the
same gland, sometimes to different glands, and some-
times unite  with  other absorbent vessels.  As they
proceed,  they  frequently enlarge in  size.   When
they have arrived near  the spine,  they frequently
form three or four trunks, and sometimes one or two;
which proceed in the course of the superior mesen-
teric artery, until they have arrived near to the aorta.
Here they either  pass  into the thoracic duct, or de-
scend and join the trunks from the inferior extremi-
ties, to form the thoracic duct.   The  absorbents of
the great intestines are not equal iu 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, proceed 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 other 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 se-
veral 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-
Axe of considerable size,  and form three  divisions.
The 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
origin of the coeliac artery.  The second arise also
on  both sides of  the stomach, and pass  to the left
extremity  of the great curvature to unite  with the
absorbents of that side of the great omentum.  They
then proceed with the lymphatics of the spleen and
pancreas, 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 human 
Absorbents of the Liver.          385
subject;  notwithstanding chyle  has been found  in
the absorbents on  the stomach  of  dogs,  and some
other animals.  It ought, however,  to be remember-
ed, 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 vis-
cus.  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 trunk, or trunks,
formed by  these vessels, either pass up between the
laminae of the mediastinum, and terminate in the up-
   Vol. II.              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
areas 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 considera-
ble numbers from the interior of the liver through the
portae.  They accompany the biliary ducts and the
great blood-vessels of the organ ;  and, after passing
through several glands, near the vena portarum, ter-
minate in the thoracic duct, near the commencement
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;
jbut they differ greatly from those of the liver, in this
respect, that the superficial vessels are remarkably
small in the human subject.
  Mascagni  however asserts, that when the blood-
vessels of the spleen are injected with size,  coloured
with vermilion, these absorbents will be filled  with
colourless size.
  In the spleen of the calf the superficial absorbeuts
are  remarkably* large. 
  Absorbents of the Pancreas.—Thoracic Duct. 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 numerous,
and also large.   They accompany the splenic  arte-
ry; 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 Absoi'bents 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 vertebrae.
  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 con-
siders it a vein  for the nourishment of the thoracjp viscera. Ed, 
 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, iu
the upper part of the thorax, as above mentioned;
and is then  so near the left lamina of the mediasti-
num, 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, iu 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 minute-
ly injected.
   Mascagni observes, that the superficial vessels are
very visible when any  fluid  has been effused  into
the cavity of the thorax ; or wheu  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 the Lungs.
child;  in which case the air passes rapidly into
them.
   The deep-seated absorbents accompany the blood-
vessels and the ramifications of the bronchiae. They
pass to the dark coloured glands, which are situat-
ed on the trachea  at  its  bifurcation;  and on  those
portions  of the  bronchiae 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
numerous, 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 Glandulx
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. 
393      Absorbents of the Head and Neck.
                   SECTION I.

     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
obtained, respecting the extent,  or  arrangement of
the absorbent 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.   Ou the
occiput  they pass  down, inclining towards the ear,
and continue behind it to the side of  the neck; be-
hind 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 tbe 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 fingers, 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 extremi-
ties are continued 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 5
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 aud
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
middle 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  euter into  the
glands there;  those which are deep-seated, joining
the. deep-seated vessels.  The  absorbents  of  the
mammae pass to the same glands;  and  when they
are affected, wijh 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

rious 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 exa-
      mined 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  Academy of Sciences a short time before the meetings of that
body were suspended. It was published by  M. Fourcroy,  in  La
Medicine Eclairee par les Sciences Physiques, vol. iii.  An extract
from M. Fourcroy's publication may be seen in the 19th chapter of
the first volume of Dr. Currie's " Medical Reports on the Effects of
Water," &c, in which is also contained a statement of the Doctor's
own 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.t
    ^.bout the  middle of the  last century, it was generally
      believed  by anatomists,  that absorption was performed
      by the veins.  Tim doctrine seemed to be established
      by the experiments of Kaaw Boerhaave, which are re-
      lated, with many other  interesting statements, in his
      work entitled *' Perspiratio  Dicta  Hippocrati," &c,
      published at Leyden, 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 Thesis  of Dr. Rousseau was published in 1800.   Those of
Drs. Klapp and Daingerh\ Id in 1805.  Dr. Mussey publishedin the
Third Supplement to the Medical and Physical Journal of Dr. Bar-
ton, in 1809.  Dr. Stewart published in 1810   Additional observa-
tions by Drs. Klapp, Rousseau and Smith, are published in the Phi-
ladelphia Medical Museum, vol. i. new series.
  •f 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-
       have is  of course  supposed  to have been mistaken;
       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; which he has
       observed to take place to a great degree.
     In the year 1809, a  memoir was presented to the na-
       tional institute of France by Messrs. Magendie and
       Delile, 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
jn  Mammiferous Animals."  A translation of it was published in the
Medical and Philosophical Register of  New York,  and in several
Other periodical 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 circumstanced,
      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 intro-
      duced into the intestine while all its connexions  with
      the body were entire.  This experiment, they assert,
      was repeated several times, without any difference 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 undivided.
      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  manner.  There  was,
      therefore, no communication between 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  occa-
      sioned the death of the animal: its deleterious effects
      commencing about four  minutes after  its  application
      to the foot.  This experiment appears to prove deci-
      dedly that the blood is the vehicle by which poison,
      when applied to the extremities, is carried to the body;
      although  it may not determine  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 Pro-
fessor Chapman's Medical and Physical Journal for February 182,.
No. 10.—Ed. 
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 poison, 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 exhibited
       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 com-
       pletely ascertained by  the  experiments  and obser-
       vations of Hunter, Cruikshank,  Mascagni,  &c, say
       further, that,  in  their opinion, the  above  mentioned
       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 Sangidferous
       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 respecting 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 iu
      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 the Medical and Physical Sciences, No.  6, in a report of
a Committee of the Academy of Medicine, signed by Doctors Law-
rence, Harlan, and Coates, of this city.—And a continuation of the
same will be found in No. 10, of the same Journal, signed by Doc-
tors Lawrence 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 Lawrence is no
more.—Ed . 
APPENDIX.
                 OF 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
exceeds it in quantity.
  The  solid part  which  thus appears  upon the
spontaneous  separation of the blood, is denominated
Crassamentum or Cruor: the fluid part is called Se-
rum.
  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 complete-
ly  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, aud appears to
be very lightly tinged with a greenish yellow colour;
but  it  is very often  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 quautity 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,  aud 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  iu

   * See Hewson, Vol. I. p. 139.—I suspect that some particular
 management is necessary in the use of rennet.
   ■j- In hisResearches on the Blood communicated to the Royal So-
 ciety of London in  1812, and  republished in the Eclectic Reper
 tory, for April 1813. 
            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 (theterm applied to the last mentioned fluid) con-
 tains no gelatine; but that, with a minute quantity
 of albumen, it consists of a large portion of an animal
 matter, which is different either from gelatine or al-
 bumen,  being unlike either of them in its chemical
 qualities.

                THE CRASSAMENTUM

 Is rendered very different in it!*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 animal,
 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 adhe-
 ring 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 appearsf to have all the chemical properties
 of the fibrous  matter of  muscular flesh.   It also re-
 sembles the gluten of vegetables, being soft and elas-
 tic. 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 M^dico-
Chirurgical Transactions, Vol. II, republished in theEclecti. Re-
pertory, for October 1812.
  f By the experiments of Mr. Charles Hatchett, published iu the
London Philosophical Transactions for 1800. 
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 conditions,
it does not take place at all.*
  In a majority of dead subjects the blood  is found
more or less coagulated in the  veins ; but  in some
subjects it is found without coagulation.   It is as-
serted that it does not coagulate in subjects who have
died suddenly, in consequence of anger, lightening,
or a blow on the stomach.

             THE COLOURING MATTER.

  When the blood vessels iu 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
Transactions.!

  * See an Inquiry into the Properties of the Blood, by the late Wm.
Hewson : and Experiments by his son, T. T. Hewson, in the Eclec-
tic Repertory, J.in 1811.—See also a Treatise on the Blood, &c. by
the late J. Hunter.
  f Among the aiost distinguished of these observers were Father
de la Torre, Haller, Hewson, Fontana, Spalanzani, J. Hunter Ca-
vallo.
  Some short accounts of Leuwenhoeck's original observations on
the blood are to be found in the Philosophical Transactions of Lon- 
             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 than 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

 don, for 1664, in the fasciculi which are numbered 102 and 106.   A
 more full description is contained in Boerhaave's Academical Lec-
 tures 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 ob-
 servations by the Rev. Father himself. The letter and the observa-
 tions are published in the 55th volume of the Transactions of that so-
 ciety.
  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, Brad-
 ford'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, Vincentius 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
appeared more like rust of iron  than iron filings.
  He  believes the  seat of this iron to be in the
 colouring matter of the blood,  as neither  the serum
nor fibrine  appeared to contain it.  According to his
 calculation, 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 ex-
pressed  on this subject  by several physiologists,
and especially 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 opi-
nion  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, in 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
alkali,  if the colour has been  destroyed by an acid.
The  colour  of  blood,  on the contrary, when once
destroyed, 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 former
 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 iu 1812, relates  many ex- 
408   Appendix.—Structure of the Glands.

periments which were made on the colouring matter
of that fluid, with acids, alkalies, astringents, &c. &c.
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 insure 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
derived from the blood vessels is called secretion.
  A structure of this kind seems  to exist in very
different 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 diffused on some  very extensive surfaces.  The
gastric liquor, a most  important secretion, is proba-
bly discharged from vessels which open,  like exha-
lents, on  the internal surface of the stomach; and
not from any circumscribed  bodies, which are  gene-
rally denominated 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 ; but 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
Sehneiderian 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 he
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 gland-
ular 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-
cunx.
  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 suc-
cessively diminish.   The smallest of these are de-
nominated  Acini.  Each of them is connected by a
  Vol. II.             52 
 414     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 texture,
 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 execretory ducts without the intervention of any
 cavity or follicle ;  that the small bodies, which had
 been supposed to contain  follicles  or cripae,  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.     410

  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
criptse, 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 be-
lieved 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.
He supposes that glands contaiu a great number of
•See Experimental Inquiries, vol. ii. p. 178. 
412     Appendix.—Structure of Glands.

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, iu 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-
mified 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 com-
monly taken up by the absorbent vessels of the kid-
neys ; for in two  cases iu which he found the ab-
sorbent vessels obstructed, a diabetes existed, which
he considered as the effect of the inactivity of the ab-
sorbents.   He  asserts, that  in the liver,  pancreas,
mammae,  and  also in  the  salivary  and  lachrymal
glands, the  minute arteries and veins are also distri-
buted upon the surfaces of cells ; and that very small
canals arise from these cells, and unite to form the
small branches of the excretory 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  wonderful
       effect upon the fluids which pass through them.  It re-
       mains yet to be ascertained why one structure forms
       saliva and another bile;  or why so  much apparatus
       should be necessary for  the secretion of milk, when
       adipose  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 divided, se-
       cretion will cease,  notwithstanding the continued cir-
       culation of the blood.  From this, he thinks, that se-
       cretions 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 separating 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 electrical power, which can be
       employed for that purpose ? &c.
           See  the London  Philosophical Transactions, foi
              1809, Part Il.t

   * The late Dr. W. Hunter, in his Medical Commentaries, (p. 40,)
 avowed his belief, that the fluids, which appear occasionally in the
 various cavities of the body,  transude through the coats of the blood
 vessels.  Mr. Hewson (Experimental Inquiries, Vol. II. Chap. 7.]
 suggested several reasons for  dissenting from  this opinion ; but
 Mascagni has endeavoured to support  it.—See a long notu to the
 above mentioned section  of his work, page 74.

   f Mr. Wollaston has also published a small paper on this subjec'
 in the Philosophical Magazine, Vol. 3i 
 
                  GLOSSARY,*

EXHIBITING THE DERIVATION OF CERTAIN ANATOMIQAL
                        TERMS.
                           A.

ACETABULUM. The cavity which receives the head of the
  thigh-bone;  from acetum vinegar: so called, because it re-r
  presents 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 otpoj extremity,
  and a/tttt the shoulder.
Anastomosis. The  communication  of vessels with  one ano-
  ther; from «r« through, and yo/*« mouth.
Anatomy. The dissection of the human body; from «»«, and
  i-ijuto to dissect.
Anconeus. A muscle; so called from «>»6iv  the elbow.
Aorta. AepT» from; *** air, and *»§«« to keep.
Aponeurosis. A tendinous expansion;  from  ««■«, and Mi/pov 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  ccttoqvu to proceed
  from.  A  synonyme of process.
Arachnoides. A net-like membrane ; from ap«^v» a spider, and
  «//o; likeness.
Artery. From «ug air, and n%w to keep ; because the ancients
  supposed that air only was contained in them.
Arthrodia. A species of connexion of bones; from  «p0po« to
  articulate.
Arytsenoides. The name of two cartilages of the larynx; also
  applied to some muscles of the larynx; from «pvra<v* a fun-
  nel, and «t<foc 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 asf*y***t 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 «tx«k» to sustain, be-
  cause it sustains the head.
Azygos. A term applied to parts without a fellow, from * priv.
  and £i"yes a yoke, because it has no fellow.

                            B.
Bursa.  A bag; from /3vp<r«: generally  applied  to the bursse
  muscoafe.

                           C.
Cancelli. Lattice work; generally applied to  the  reticular
  substance in bones.
Cardia.  The superior opening of the stomach ; from **p$/« the
  heart.
Carotid. The name of some arteries of the neck and head from
  iiapo* to cause to sleep ; for, if tied with a ligature, the  ani-
  mal was said to be affected with coma.
Carpus. Kaphas j the wrist.
Claviculu. The clavicle or collar-bone, a diminutive of elavia
  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 *x«» a bed, and ttJot likeness ; from their
  supposed  resemblance to a couch.
Clitoris.  A part of the  female pudenda, enclosed by the labia
  majora; from kUiu to enclose or hide.
Colon. The first of the large intestines; from *«\oy, quasi koixov,
  from *o/xoc hollow.
Coracoid. From xog«£ a crow,  and uhs 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 *.otuM the name of an old measure, and «/cfos re-
  semblance? resembling the kotule.
Cranium. The skull; *p««oy, quasi *«p«/oy, from %«p« the head.
Cremaster.  A muscle so called ;  from *gi/*a« to suspend, be-
  cause it suspends the testicle.
Cribriform. From cribrum a  sieve, it being perforated like a
  sieve. 
                       Glossary.                   41*

Cricoid. Annular, round like a ring; from x$«t»c a ring,  and
  tt}o5 likeness.
Cuhoides.  A bone of the foot;  from *wCot a cube, and  «»<Toe
  likeness; because it resembles a cube.
Cuneiform. Some bones arc 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 ««foc resemblance.
Diaphragm. The muscle  which separates the thorax from
  the abdomen;  from <T/«<j>f«tJ» to divide.
Diarthrosis. A moveable connexion of bones; from A«g*go« to
  articulate.
Digastric. From «f/c twice, and y*s*z a belly ; having two bel-
  lies.
Diploe. The spongy substance between the two tables of the
  skull; from c/WAo* to double.
Duodenum. The first portion of the small intestines ; so called
  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 iftfyu* to bud
  forth.
Enarthrosis. An articulation of bones; from «in, and a^flgo* a
  joint or articulation.
Enteric. Belonging to the intestines; from wt^ot an entrail or
   intestine.
Epidermis. The scarf or outermost skin ; from «n upon, and
   £iqt*.K the skin.
 Epididymis. The small oblong body which lies above the tes-
  ticles;  from tin upon, and frfvptK; a testicle.
 Epigastric. The superior part of the abdomen ;  from «*•< upon,
   and >*«T>i£ the stomach.
 Epiglottis. A cartilage of the larynx so called; from %*t upon,
   and v\«it?ic the aperture of the larynx, being situated  upon
   the glottis.
 Epiphysis.  A portion of bone growing upon another bone, but
    Vol.  II.                53 
418
Glossary.
  separated from it by a cartilage: from iwi upon, and q>uu to
  grow.
Epiploon. The membranous viscus of the abdomen, which co-
  vers the intestines, and hangs to the bottom of the stomach;
  from tiwrxta to swim upon.
Ethmoid.  From ifl^ec a sieve, and n/of resemblance; being per-
  forated 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. Tafyxm, a  knot in the  course of a nerve.
Gastrocnemius.  The muscle which forms the thick of the leg;
  from >*$*f a belly, and k»»^» the leg.
Genio. Names compounded with  this word belong to muscles
  which are attached  to  the chin, as genio-glossus—genio-
  hyoideus, &c; from >«s<ov the chin.
Ginglymus. An articulation;  from yiTyhv^t a hinge.
Glenoid  cavity.  From >x»v» a cavity, and »/<foe resemblance.
Glosso. Names compounded with this word belong to muscles
  which are attached to the tongue; as glosso-pharyngeus—
  glosso-staphilinus, &c; from ywvva the tongue.?
Glottis.  The  superior opening  of the  larynx at the bottom of
  the tongue: from yxur\* the  tongue.
Glutseus. The name of a muscle; from >x«toc the buttocks.
Gomphosis. return?,  a species of immoveable connexion of
  bones; from ycp.<poe a nail, because one bone is fixed in ano-
  ther bone like a  nail in a board.

                           H.
Helix. The outward circle of the  ear; from uum to turn about.
Hepar. The liver.  'Hw«g an abdominal  viscus.
Hyaloid. From i3*xoC  glass, and afot likeness; the capsule of
  the vitreous humour of the eye is so called, from its trans-
  parent and glassy appearance.
Hymen. The membrane situated at the entrance of the virgin
  vagina;  from  y>>iv Hymen, the god of marriage.
Hyoides. A bone of the tongue, so called from its resemblance
  to the Greek v;  from v, and  mfot resemblance. 
Glossary.
419
Hypochondriurn.. That part of the body which lies under the
  cartilages of the spurious ribs; from i** under, and x6'^{«c
  a cartilage.
Hypogastric. The lower region  of the fore part of the abdo-
  men ; from «V» under, and y«c»£ the stomach.

                            I.
Reon. A portion of the small intestines; from #«Xt» to turn j
  being always  convoluted.
Ischium. The part of the os innominatum upon which we sit;
  from^e-^wa 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 let-
  ter x; from x, and t/2os resemblance.
Larynx. The superior part of the windpipe; x<*{«;>£ the larynx.

                           M.
Masseter. A muscle of the face, which assists in the action of
  chewing; ftetaraofxcu  to chew.
Mastoid. From /t*«*o$ a breast, and u<fot likeness;  shaped like
  a nipple or breast.
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 /u«<ro$ the middle, and «t«^o» 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 /uiroj the middle, and *oxo» the colon.
Metacarpus. That part of the hand between the carpus and fin-
  gers ; from /u«t« after, and x«^ot the wrist.
Metatarsus. That part of the foot between the tarsus and toes;
  from pnx after, and  Tago-oj the tarsus.
Mylo. Names compounded with this word belong to muscles
  which are attached near the grinders, as mylo-hyoideus, &c. J
  from /ukAi; a grinder  tooth.

                            0.
 Odontoid. Tooth like;from o3*catooth, and ufrtresemblance.
 (Esophagus. The canal leading from the pharynx to the sto-
  mach ; from o,« to carry, and <?«>«• to eat; because it carries
   the food into the stomach. 
42Q
Glossary.
Olecranon.  The elbow, or head of the ulna; from «x««? the cu-
  bit, and xgavot 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 af*ot the shoulder.
Omoplata.  The scapula or shoulder blade; from «/*os the shoul-
  der, and  ir\*Tvt broad.
Osteology.  The doctrine of the bones; from o$io» a bqpe, and
  Xoytc a discourse.

                           P.
Pancreas.  A viscus of the abdomen ; so called from its fleshy
  consistence ; from km  all, and Kgtat flesh.
Parenchyma.  The  substance  of some of the viscera was so
  called, from va^nuu to pour through.
Parotid Gland; from *«g« near, and owe the ear; because it is
  situated near the ear.
Pelvis. A bony cavity  shaped  like a basin ; from wixuc a basin.
Pericardium.  The membrane which surrounds the heart; from
  ittft around, and xagJ1** the heart.
Pericranium.  The  membrane  which covers the bones of the
  skull;  from *•«§/ around, and x{««o» the cranium or head.
Periosteum. The membrane which surrounds the bones ; from
  Ttg* around, and  oy»o> a bone.
Peristaltic motion of the intestines;  from «*^us-xx«, to contracL
Peritoneum. The membrane lining the  abdomen, and cover-
  ing its  viscera; from jn^nwa to extend around.
Phalanx. The bones of the fingers and toes are called pha-
  lanxes, from  their regular  situation,  like a <fK,\*y%, or ar-
  rangement  of soldiers.
Pharynx. A membranous bag at the end of the mouth ; ttrro t*
  <pi£«n, because it conveys the food into  the stomach.
Phrenic or  diaphragmatic nerve, p^mc  the diaphragm ;  from
  (ppi 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 ; *-Xft/g« the side.
Plexus.  A kind of net-work of vessels or nerves ; fromplecto
  to weave together.                               * 
Glossary.
421
Psoas. A muscle so called; from 4<>« the loin, being situated
  in the  loins.
Pterygoid process. From <T?#gi/£ a pen or wing,  and ««T»« 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 w*xo« to guard an entrance, because it
  guards as it were the entrance of the bowels.

                             R.
Raphe. A suture; from p*w7«  to sew.
Renes. The kidneys, «*o r* fuv, 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 pepSoc
  a geometrical figure,  whose sides are equal but not right-
  angled,  and f<<f«j a likeness.
Rotuta.  The knee-pan ; a dim. of rota a wheel, from its shape.

                             S.
 Sacrum. A bone so called; from sacer sacred, because it was
   oiA;e offered in sacrifices.
 Salvatella. 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; are  t* <r««vy«//«, 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-helix;
   from  aK*<t» a little boat  or skiff.
 Scaphoides.  A bone of the carpus,  so called from its resem-
   blance to a skiff; from  cr*«<p» a skiff, and ti<rc( likeness.
 Sclerotic.  A term applied  to  the outermost  or hardest mem-
   brane of the eye; from  <ne*»>{oa to make hard.
 Sesamoid bones. From rmrtun a grain, and »/<P« likeness; from
   their resemblance to the semen sesami.
 Sigmoid. Parts are so called from their  resemblance to the
   letter 2;  from S, the letter Sigma, and «//«c likeness.
 Sphenoid. From <r<j.»y a wedge, and  u«fos 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
   <r<piyyu to shut up.
 Splanchnic. From ffjrxay;tvo«> an entrail. 
422
Glossary.
Symphysis. A connexion of bones;  from cv^va to grow to-
  gether.
Synarthrosis. A connexion of bones; from <rw with, and «pfl^ot
  a joint.
Synchondrosis. A species of union of bone3 by means of car-
  tilage; from e-i/v with, and x^^fs a  cartilage.
Synneurosis.  A species of connexion of bones by means of
  membrane ;  from rw» with, and «vpe$ a nerve; 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 cut with, and a-atf flesh.
Systole. The  contractile motion  of the heart and arteries;
  from ewnxxa to contract.
                          T.
Tendon. From Tf/»« to extend.
Thorax. ©«g«|. The breast or chest.
Thyroid. From 0</gioc a shield, and «//oj likeness; shaped like
  a shield.
Trachea. The windpipe, so called from its roughness; from
  rt*xv< rough.
Trochanter. A process of the thigh-bone, so called from rgo^ot
  a wheel.
                          U.
Ulna. A name for the cubit; from axtm the cubit.
Ureter. The canal which conveys the urine from the kidney
  to  the bladder;  from *$ov urine.
Urethra. The passage through which the urine passes from
  the bladder; from «jo» the urine.
Uvea. The  posterior lamina 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 mid-
  dle of the soft palate: so called from its resemblance to a
  grape. A dim. of uva a grape.
                           V.
Valves. From valvse folding doors.
Vertebrse. The bones of the spine are so called ; from verto to
  turn.
                           X.
Xiphoid. So called from the resemblance to a sword; from
  £«j>o; a sword, andwfos likeness.
                           Z.
Zygoma. The cavity under the zygomatic process  of the tem
  poral bones; from £«>oj a yoke. 
ALPHABETICAL INDEX TO VOLUME II.
	Page		Pasre
Aorta 50 & 236		Artery, internal maxillary245	
Adhesion of lungs	73	mammary257	
Abdomen	82	intercostals supe-	
regions of	86	rior	260
contents of	85	interosseal	267
situation of vis		intercostals infe-	
cera	87	rior	272
Acini of liver	132	iliac primitive	282
Arteries, structure of	226	internal	283
Artery, axillary	262	ilio lumbar	284
aorta thoracic	270	iliac external	288
abdominal	274	internal plantar	296
adipose	281	ischiatic	286
anastomotic	292	lingual	242
anterior tibial	294	lumbar	282
basilic	259	middle of brain	255
bronchial	270	mammary exter-	
carotid	239	nal	262
external	240	mesenteric supe-	
internal	250	rior	278
callous	256	infe-	
cervical	261	rior	279
circumflex	564	occi-	
cceliac	275	pital	244
capsular	280	ophthalmic	252
circumflex of ili		oesophageal	271
um	289	obturator	285
ofthig	h-291	pharyngeal infe-	
emulgent	280	rior	243
epigastric	288	phrenic	274
facial	242	pudic internal	287
femoral	289	external	290
gastric	275	profunda femoris	290
right	276	perforating	291
left	277	I popliteal	292
gluteal	286	posterior tibial	295
humeral	264	peroneal	ib.
hepatic	276	plantar external	296
heemorrhoidal	285	radial	266
innominata	238	stylo-mastoid	245
VOL. II.	a		
 
11
INDEX.
Artery, subclavian       256
       scapular superior 260
                internal 263
       spiral            265
       splenic          277
       spermatic        281
       sacral  middle    28
              lateral     284
       thyroid superior  241
               inferior   258
       temporal         249
       ulnar            268
       uterine          286
       vertebral         258
Arterial system, plan of  l297
Abdominal viscera, nerves
  of                    368
Absorbents, structure of  371
           of lower ex-
             tremity    376
           of  abdomen   S81
           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
Coecum
Colon
Corpus pampini forme
Corpora cavernosa
Corpus spongiosum
Canal of urethra
Clitoris
Canalis arteriosus
Cava
Coronary veins
  4
118
119
174
186
188
190
201
220
299
ib.
Chorda Tympani	335
Crassamentum	403
Duodenum	IU
Ductus communis	141
Dartos	173
Ductus venosus	220
Descending cava	300
External nose	2
Eustachian tube	11
Epididymis	177
Fauces	28
Foetus, thorax of	69
heart of	ib.
lungs of	ib.
abdomen of	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
Glandulee renales        154
Ganglions               321
          ofGasser      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
 division of     109 
INDEX.
iii
Intestines), small	110	Nerves, lumbar	353
Integuments of penis	195	laryngeal superior 339	
Ilium	113	maxillary inferior 332 ^ *	
		superio	r3i9 »•*
Jejunum	113	musculo cutane-	T*
		ous	348 :«#
Kidneys	155	median	ib.
		ninth pair	340
Larynx	31	olfactory 6.	3:3
arteries and nerves		optic	324
of	35	opthalinic	327
Left auricle	55	obturator	355
ventricle	56	par vagum	338
Lungs	65	recurrent	339
Legallois on heart	79	radial	350
Liver	128	sixth pair	n r» ^
ligaments of	130	seventh pair	334
Labia externa	201	sacral	356
Lacteals	389	sciatic	358
Mouth	14	sympathetic	361
Mamma;	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			
		(Esophagus	94
Nose	1	Omentum	125
nerves of	8	Orifice of urethra	167
Nerves of liver	136	Ovaries	210
Neck of the bladder	167		
Nerves, structure of	319	Parotid gland	25
accessory	347	Pharynx	37
of arm	348	Pleuree	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	246	Pancreas	141
dorsal	352	Prostate gland	183
eighth pair	336	Penis	184
fourth pair	325	Prepuce	196
fifth pair	Sv6	Placenta	221
fibular	359	Plexuses	321
glosso-pharyngeal 337 internal cutaneous 351		pulmonary	340
		brachial	347
 
IV
INDEX.
Plexuses lumbar	354
f- cardiac	366
solar	367
Rima glottidis Right auricle ventricle	34 52 53
Rectum	122
Round ligaments	209
Sehneiderian membrane	5
Sinuses of nose	12
Soft palate Salivary glands Submaxillary gland	17 25 26
Sublingual gland Saliva	ib. ib.
Sabatier on foetal circula	-
tion	75
Stomach	96
lymphatics and nerves of	103
Spleen	145
Scrotum	171
Serum	
Spermatic cord	173
Tongue papillae of blood vessels of	18 20 23
nerves of	24
Throat	28
Tonsils	29
Thyroid gland	37
Thorax	41
Trachea	62
Thymus gland Tunica vaginalis	69 175
albuginea Testicle	176 177
descent of	218
Thoracic duct	387
Uvula	17
Urinary organs Ureters	154 160
Urinarv bladder	162
Urethra of male         188
        of female        202
Uterus                  205
      changes of, in preg-
         nancy          214
Umbilical arteries        219

Venae cavae               61
Valve of colon           120
Vena Portarum          134
Vessels  of liver          133
Vas deferens            180
Vesiculee seminales      181
Vagina                  203
Veins, structure of       233
      distribution of    298
Vena azygos            301
Veins, axillary           308
      anomalies of      317
      basilic            308
      cephalic           308
      Cava inferior      309
      capsular          312
      circumflex        314
      external  jugular   306
      emulgent         312
      external  iliac      314
      epigastric         315
      external  saphena  316
      femoral           315
      hepatic           311
      hypogastric       313
      intercostal superior 303
      iliac primitive      313
      jugular internal    304
      lumbar           313
      middle sacral      ib.
      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 XIX.

       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 malee. L, The os maxillare superius. M, Its nasal
 process.  N,  the ossa nasi.  O, The os unguis,  P, The maxilla
 inferior.   Q, the teeth, which are  sixteen in number  in each
jaw. R, The seven cervical vertebrse, with their intermediate
 cartilages. S, Their  Transverse  processes.  T, The twelve
 dorsal  vertebrae, with their intermediate  cartilages.   U, The
 five lumbar vertebrse.  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 niche, 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 o£
 the sternum, q, The middle piece, r, The under end, or car-
tilage ensiformis. s, The clavicle, t, The internal surface of
 the scapula,  u, Its acromion, v, Its coracoid process,  vv,  Its
 cervix.'x, The glenoid cavity, y, The os  humeri, z, Its head
which is connected to the glenoid cavity.  1, Its internal tu- 
 2     Explanation of the j-tu^.i ,*/ ^s^r .. «*■».

 bercle. 2, Its internal tubercle.
 long head of the biceps muscle  01  me arm.  •*, me internal
 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; composed of os
 naviculare, os lunare, os cuneiform, os pisiforme, os trapezi-
 um, 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 trochanter  major. 26,
 trochanter minor,  27, The internal condyle. 28, The external
 condyle. 29, The rotula.  30, The tibia. 31, Its head. 32, Its
 tubercle. 33, Its spine. 34, The  malleolus internus.  35, The
 fibula.  36, Its head. 37, The malleolus externus. The tarsus is
 composed of. 38, The astragalus ;  39, the os calcis; 40, The
 os naviculare; 41, Three ossa, cuneiformia, and the os cu-
 boides, 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 osfrontis. B, The lateral part of the os frontis> which
 gives origin  to part of the temporal muscle. C, The superci-
liary  ridge.   I),  The superciliary hole  through which the
frontal vessels and nerves pass.  EE, The orbitar processes.
 F, The middle of the transverse suture.  G, The upper part of
the orbit. H, The foramen opticum. I, The foramen lacerum.
K, the inferior orbitar fissure.  L,  The os unguis. M, The ossa
nasi. N, The os  maxillare superius. O, Its  nasal process. P,
The  external orbitar hole  through which the superior maxil-
lary  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 spon-
giosum superius. V, The  os  spongiosum inferius.   W, The
edge of the alveoli, or  spongy sockets for the teeth. X, The
maxilla inferior. Y, The  passage for the inferior  maxillary
 vessels and nerves.
            Fig.  3. A Side-view of the Skull.
   A, The os frontis.  B, The coronal suture.  C, The os pa-
 rietale. U, An arched  ridge which gives origin to the temporal
 muscle. E, the squamous suture.  F, The squamous part of the
 temporal bone: and farther forwards, the temporal process of
 the sphenoid bone. G, The zygomatic process of the temporal
 bone. H, The zygomatic suture.  I, the mastoid process of the
 temporal bone. K, the meatus auditorius externus.  L, Theor-
 biter plate of the frontal bone, under which  is  seen  the trans 
 
 
      Explanation of the Plates of Osteology.     8

verse suture. M, The pars plana of the ethmoid bone. N.The
os unguis.  0:, 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 malae.  W, The lower jaw. X, Its
angle. Y, The coronoid  process.  Z, The condyloid process
by which the jaw 13 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.  H, 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  angular process. D, The internal angular process E,
The nasal process.  F, The superciliary arch. G, The super-
Ciliary 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 ethmoid bone.
G, The passage from the frontal sinus. H, The opening which
receives the cribriform plate of the ethmoid bone. I, The ca-
vity which  lodges the fore part of the brain.  K, The spine to
which the falx is fixed.  L, The groove which lodges the su-
perior longitudinal sinus.
                       Plate XX.
          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. H, The palate plates of the superior maxillary bones.
I, 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 fifth 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. 
« 
      Explanation of the Plates of Osteology.     5

Fig. 6. The External Surface of the Osseous Cirole, which
         terminates the meatus auditorius 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 auditorius 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.
   AA, The temporal processes. BB, The pterygoid process-
 es.  CC, The spinous processes. DD, The anterior clinoid
 processes. E, The posterior clinoid process. F, The anterior
 process which joins the ethmoid bone.  G, The sella turcica
 for lodging the glandula pituitaria. H, The foramen opticum.
 K, Th6 foramen lacerum.  L, The foramen rotundum. M, The
 foramen ovale. N,  The foramen spinale.
     Fig. 16. The External Surface of the Os Sphenoides.
   AA, The temporal processes. BB, The pterygoid process-
 es.  CC, The spinous processes. D, The processes 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. 
 6     Explanation of the Plates of  Osteology.

     Fig. 17 The External View of the Os Ethmoides.
   A, The nasal lamella. BB, l he grooves between the nasal
 lamella and ossa spongiosa superiora. CC, The ossa spongiosa
 superiora.  DD, The sphenoidal cornua. See Fig.  16. E.
     Fig. 18.  he 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 eth-
 moidal cells.  D, The right as planum. EE, The  sphenoidal
 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 condyloid
 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
sinuses. GG,  The course of the two lateral sinuses.   H, The
foramen magnum. II, The posterior condyloid foramina.
                      Plate XXL
           Fig. 1. A Side-View of the Skeleton.
  A A, The ossa parietalia.  B, The sagittal suture. C, The oa
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.
O, 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,
Oppnings between the vertebrse for the  passage of the spinal
nerves. U,  The under end of the os sacrum. V, The oscoc- 
^M*'--
£&*■>

>-V
s ST

> V
v/
c»^ 
 
Explanation of the Plates of Osteology.
7
cygis. W, The os ilium.  X, The Tanterior spinous processes.
Y, The posterior spinous processes. Z, Ischiatic niche, 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 each 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,  : he
three ossa cuneiforma. 1, 'I he os cuboides. 2, The five meta-
tarsal 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, Vhe 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 xygoma, made by the joining  of the zygomatic
processes  of the os temporum and os inalfe. H, ^hepars squa-
mosa of the os temporum.  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. 0, 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.  S, 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 laternal
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 foramen incisivum, 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 palatinum posterius, for 
 8      Explanation of the Plates of Osteology.

 the palatine vessels and nerves. H, The os maxillare superius
 of the right side. I, The os malae. K, The zygomatic process
 ot  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,  l'he 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 in-
 ferior horizontal ridge of the occipital bone, ff, The superior
 horizontal ridge, which is opposite to the crucial ridge where
 the longitudinal sinus divides to form the lateral sinuses, ggg,
 The lambdoid suture,  h, The left squamous suture,  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  inner
 edge, where they join each other.
      Fig. 5.  The posterior surface of the Ossa Nasi.
  AA, 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 or-
 bitar hole. E,  The opening into the nostril.  F, The palate-
place.  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.
Fig. 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.      9

between which  and B is the cavity of the nostril.  G, The
palate-plate.  H. The orbitar part of the os palati.  I, The na-
sal plate.  K, The suture which unites the maxillary and palate
bones. L, 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
ethmpidal 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,  i he  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 In-
                         ferius.
  A,  The anterior part.  B.The hock-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 palate
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
                            R 
10      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 maxillary
and palate bones.  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, The
beginning of the inferior maxillary canal of the right side, for
the entry of the nerves and blood vessels. G,The termination
of the left canal.  H,  The two dentes incisores.  I, The dens
caninus. K, The two small molares. L, The three large mo-
lares.                                              "■
        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 an-
terior dentes molares.  9,10,11, The posterior dentes 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 XXI.
  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
ends 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.
  The spine of the scapula,  b, The acromion,  c, The infe-
rior angle, d, Inferior costa.  e, Cervix, f, Glenoid cavity co-
vered with cartilage for the arm-bone,  gg, The capsula liga-
ment of the joint,  h, Coracoid process. \, the broken  end of
tbe clavicle, k, Its extremity joined to the acromion. 1, A li-
gament 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
ligament including the head of the radius. 
	
	Uw ^
v/   o
7\    msagB^      .)

 
 
      Explanation of the Plates of Osteology.    11

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 cuneiform,  f, The os
pisiforme. g, Trapezium,  h, Trapezoides. i, Capitatum. k,
Unciforme.  1, The four metacarpal bones of the fingers.- m,
The first phalanx,  n, The second phalanx, o, The third pha-
lanx,  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 Semilu-
 nar Cartilages of the Joint of the Knee, and some Ligaments.
  a, The strong ligament which connects the rotula to the tu-
bercle of the tibia.  bb,The parts of the extremity of the tibia,
covered with cartilage,*which appear within  the  semilunar
cartilages, cc, The semilunar cartilages, d, The two parts of
what  is called the cross ligament.
Fig. 7. '! he 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, on 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.
Fig.  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 cuhoides. 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, 
12   Explanation of the Plates of Osteology.

The metatarsal bones of the great toe. r, Its first—s, Its <p-
co \d joint.
Fig. 10. The Inferior Surface of the two large Sesamoid Bcnes,
            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
tendon-, nerves, and blood ves-els.  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, TThe 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. flf, The posterior sides of 'g) the thyroid cartilage, hh,
Its superior cornua.  ii, Its inferior cornua. k, The cricoid
cartilage. 11, The arytenoid cartilages,  m, The entry into the
lungs, named  glottis, n, The epiglottis, oo, The superior car-
tilages  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 they are formed. 
 
 
     Explanation of the Plates of the Muscles.   13



   EXPLANATION OF PLATES XXIII and XXIV.

                    PLATE XXIII.
  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-fron-
talis. C, Attolens aurem.  D, The ear. E, Anterior auris. FF,
Orbicularis  palpebrarum. G, Levator labii superioris alaeque
nasi. II, Levator anguli oris.  I, Zygomaticus minor. K, Zy
gomaticus major.  L. Masseter. M, Orbicularis oris. N, De
pressor labii inferioris. O, Depressor anguli oris.  P, Buccina-
tor.  QQ, Platysma inyoides.  RR,  Sterno-cleido-mastoidieus.
S, Part of the trapezius.  T, Part of the scaleni.
   Superior Extremity.—U, Deltoides. V, Pectoralis major.
W,  Part  of the latissimus dorsi.   XX, Biceps flexor cubiti.
YY, Part of the brachialis externus. 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
internus.  c, Pronator radii teres, d, Flexor carpi radialis. e,
Part of the flexor carpi ulnaris. f, Palmaris longus. g, Aponeu-
rosis palmaris.  3, Palmaris brevis.  1,  Ligamentum carpi an-
 nulare. 2 2, Abductor 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 subli-
 mis 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, Coracobrachial is. qq, The long
 head of the triceps extensor cubiti. rr, Teres  major, ss, Sub-
 scapularis. tt.Extensoresradiales. u, Spinator brevis. y, The
 cut extremity of the pronator terres. w, Flexor sublimis per-
 foratus.  x, Part of the flexor profundus,  y, Flexor pollicis
 longus. z,  Part of the flexor pollicis brevis. 4, Abductor mi-
 nimi digiti. 5, The four lumbricales.
   Trunk.—6, Serrated  extremities of  the serratus aoticua
 niajor. 7 7, Obliquus externus abdominis.  8 8, The linea al 
14   Explanation of the Plates of the Muscles.

ba.  9, The umbilicus.   10. Pyramidalis.   11 11, The sper-
matic cord.  On the left side it is covered by the cremaster.
12 12, Pectus abdominis.  13, Obliquus internus. 14 H, &c.
Intercostal muscles.
  Inferior Extremities.—a a, The gracialis. bb, Parts of
the triceps,  cc, Pectialis.  dd. Psoas  magnus.  ee,  Iliacus
internus.  /,  Part of the glutaeus medius.  g, Part of the glu-
taeus minimus,   h,  Cut extremity of  the  rectus cruris,  i i,
Vastus  externus.  k, Tendon of the rectus cruris. It,  Vastus
internus.  * Sartorius muscle.  ** Fleshy origin of the tensor
vaginae faemoris 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 cru-
ris,  p, Crureeus.   qq, The tibia, rr, Part of the Gemellus,
or gastrocnemius externus. sss, Part of the soleus or gastroc-
nemius internus. I, Tibialis anticus. u, Tibialis posticus, vv,
Peronaei muscles, ww, Extensor longus digitorum pedis, xx,
Extensor 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 Platysma
  myoides have been taken off.
  a, The frontal muscle, b, Temporalis and temporal artery.
c, Orbicularis palpebrarum,  d, Levator labii superioris alse-
qui nasi,   e, Levator anguli oris,  f, Zygomaticus.  g, De-
pressor labii inferioris.  h, Depressor  anguli oris,  i, Bucci-
nator,   k,  Masseter.  11, Parotid  gland,   m, Its duct,  n,
Sterno-cleido-rnastoideeus.  o, Part  of  the trapezius,  p,
Sterno-hyoidaeus.   q, Sterno-thyroidaeus.   r, Omo-hyoideeus,
f, Levator scapulae, tt,  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  palpebree superioris.   d,  Tendon   of the orbicularis
palpebrarum,  e, Masseter.  f, Buccinator,  g, Levator an-
o-uli oris,   h, Depressor labii superioris alseque nasi,   i, Or-
bicularis oris,  k, Depressor anguli oris.  1, Muscles  of the
os hyoides.   m, Sterno-cleido-mastoidseus.
Fig. 4. Some of the Muscles of the Os Hyoides and Submax-
                      illary Gland.
  a, Part  of  the  masseter muscle,  b, Posterior head of the
digastric,   c, Its anterior  head,   dd, Sterno-hyoidaeus.  e,
Omo-hyoideeus.  f,  Stylo-hyoidseus.  g, Submaxillary  gland
in situ. 
 
*     1
4-    « 
     Explanation of the Plates of the Muscles.   15

        Fig. 5, The Submaxillary Gland and Duct.
  a, Musculus mylo-hvoidgeus. b, Hyo-glossus.  c, Submaxil
lary gland extra situ, d, Its duct.

                      Plate XXIV.
  Fig. 1, The Muscles immediately under  the common te-
guments on the posterior part of the body, are represented on
the right side: and on the left side the Mvscles 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-
goidaeus internus.
  Trunk.—Rightside. FFF, Trapezius seu cucularis.GGGG,
Latissimus dorsi. H, Part of the obliquuis exteraus abdominis.
  Trunk.—Left side. I, Splenius. K,  Part of the complexus.
L, Levator scapulae. M, Rhomboides.  NN,  Serratus posticus
inferior. 0, Part of the longissimus dorsi. P, Part of the sacro-
lumbalis.  Q,  Part of the semi-spinalis dorsi. R, Part of the
serratus anticus major.  S, Part of the obliquus internus ab-
dominis.
   Superior Extremity.—Right side.  T, Deltoides.  U, Tri-
ceps extensor cubiti.  V, Supinator longus. WW, Extensores
carpiradialis longior and brevior.  XX. Extensor carpi ulnaris.
YY, Extensor digitorum communis. Z, Abductor indicis. 12 3,
Extensores pollicis.
   Superior Extremity.—Left side, a, Supra Spinatus.b, In-
fraspinatus, c, Teres minor, d, Teres major,  e, Trjceps exten-
sor cubiti. f f, Extensores carpi radiales. g, Supinator brevis.
h, Indicater. 1 2 3, Extensores  pollicis.  i,  Abductor minimi
digiti. k, Interossei.
   Inferior Extremity.—Right side.  1, Glufaeus maximus.
m, Part of the Glutaeus medius.  n, Tensor vaginae femoris. o,
Gracilis, pp, Abductor 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, Peroneeus longus and brevis. y, Tendons
of the flexor longus digitorum pedis;—and underthem *flexor
brevis digitorum pedis, z, Abductor minimi digiti pedis.
   Inferior Extremity.—Left  side, m, n, o,pp, q, r, s, /, v, w
iv, x x, y, z, Point the same parts as jn the right side,  a, Pyri-
formis. b b, Gemini, cc. Obturator* internus. a, Quadratus fe-
moris.  e, Coccygaeus.  /, The short head of the biceps flexor
cruris, gg, Plantaris. h, Popliteeus. i, Flexor longus pollich
pedis. 
16   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 sublimis; which are performed bv 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
peroeaeus 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, Accele-
rator urinae. h, Corpus cavernosum urethrae.
             Fig. 5. 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 XXV, XXVI  and XXVIL

                      Plate XXV.

Fig. 1. Shows the Contents of the Thorax and Abdomen In
                         situ.
   1, Top of the  trachea, or wind-pipe.  2 2, 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.  17 17,  The
jejunum and ilium. 18, The spleen. 

G
 
 
      Explanation of the Plates of Osteology.    it

Fig. 2, Shows the organs subservient to the Chylopoietic Vis-
        cera,-   with those of Urine and Generation.
  11,  1 he 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 kidneys.
7, The aorta descendens.  8, Vena cava ascendens. 9 9, The
renal veins covering the arteries. 10,  A probe under the sper-
matic vessels and  a bit of  the inferior mesentric artery, and
over the  ureters.   11 11, The ureters.  12 12, The iliac ar-
teries and veins. 13, The rectum intestinum. 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 utu'er 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. H, The sto-
mach. KK, Venae and arteriae gastro-epiploieee, dextrae and
sinistra. LL, Venae and arteriae coronariae ventriculi. M,The
spleen.  NN, Mesocolon, with its vessels.  000, Intestinum
colon. P, One  of the ligaments  of the colon, which is a bun-
dle of longitudinal muscular fibres. QQQQ, Jejunum and ilium
RR, Sigmoid flexure of the colon with the ligament continued,
and over. S, The rectum intestinum. 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 Right Auricle  cut open to show the Foramen  Ovale,
   or passage between both Auricles.
   a, The right ventricle,  b, The left ventricle, cc, The outer
 side of the  right auricle stretched out.  dd,  he posterior side,
 which forms the anterior side of the septum, e, '! he foramen
 ovale, with the membrane or valve which covers the left side.
 f, Vena cava inferior passing through,  g, A portion of the di-
 aphragm.
 Fig. 5. Shows the Heart and  Large  Vessels of aFcetus at the
                         full time.
    a, Th^left  ventricle, b, The right ventricle, c, A part of
 the right auricle,  d, Left  auricle, ee, The right branch of the
 pulmonary Artery, f, Arteria pulmonalis.  gg, The left branch
 of the pulmonary arterv,with a number of its largest  branch-
 es dissected from the lungs, h,  i he  canalis arteriosus, i. The
 arch of the aorta, k k, ■ he aorta descendens. 1, The left sub-
 clavian artery, m, The Left carotid artery, n, The right carotid
                             C 
18    Explanation of the Plates of the Muscles.

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  XXVI.

  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 artery.
G, The mosculus gastrocnemius.  H, The tibia. I, The tendon
of the musculus tibialis antrcus.  On the outlines,  a, A lym
phatic vessel belonging  to the top  of the foot, b, Its first di-
vision into branches,  c, c,  c, Other divisions of the  same lym-
phatic vessel, d, A small lymphatic gland, e,The lymphatic
vessels which lie  between  the skin and  the  muscles of the
thigh,  ft', Two  lymphatic   glands  at the  upper part of the
thigh below the groin, gg,  Other glands, h, A lymphatic ves-
sel  which passes  by  the side  of those glands without com-
municating with them ; and bending towards the inside of the
groin  at (i,) opens into the  lymphatic gland (k.) 11, Lympha-
tic glands in the groin, which are  common to the lymphatic
vessels of the genitals and  those  of the lower extremity, m,
n, A plexus  of lymphatic vessels  passing on the inside  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 out-lines j
 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.    19

deep-seated lymphatic vessel passes,   d, The lymphatic ves-
sel passing under a small part of the soleus,  which is left at-
tached 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
lymphatic vessel passing with the crural artery, through the
perforation 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 ca-
va superior. DDDD, The subclavian veins. E, The beginning
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 exter-
nal iliac  arteries,  g, d,  The musculi psoae.  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,  bb, The lymphatic vessels  of the lower ex-
tremities passing under Poupart's ligament,  cc, A plexus of
the lymphatic 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 con-
tained in that cavity, next ascends and passes behind the iliac
arterv to {g.)f, Some lymphatic vessels of the left side pass-
ing over the upper part of the os sacrum; to meet those of the
right side,  g, The right  psoas, with a large plexus of lympha-
tics lying on its inside,  hh, The plexus lying on each side of
the spine,  ii i, Spaces occupied by the lymphatic glands, k,
The trunk of the lacteals lying on the  underside of the supe- 
20  Explanation of the Plates of the Muscles.

rior mesenteric artery. I, The same dividing into two branch-
es, one of which passes on each 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 pe-
netrating the thorax,  p, Some lymphatic vessels joining that
duct in the thorax,  q, The thoracic 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 lym-
phatic vessels passing upon the trachea from the thyroid gland
to the thoracic duct.
                     PLATE  XXVII.
Fig. 1. Represents the Under and Posterior Side of the Blad-
                     der 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 vericula 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 ureth-
rse. i, Urethra,  k.  Septum penis. 11, The Septum between
the corpus cavernosum urethra 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 the os sacrum.  1,
Its fundus.  2, Its cervix, bb, The fallopian or uterine tubes,
which open into the cavity of the uterus;—but the other end
is open within the pelvis, and surrounded by c c, The fimbriae.
d d, The ovaria.  e, The os internum uteri, or  mouth of the
womb, f f, The ligamenta rotunda, which  passes without the
belly, and is fixed to the labia pudendi. gg, The cut edges of
the  ligamenta lata, which connects  the uterus to the pelvis.
h, The inside of the vagina,  i, The orifice of the urethra, k,
The clitoris surrounded by (1,) The praeputium. mm, The la-
bia 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 tbf 
 
Plate .XX V1U
C,. /-W.IJ- 
     Explanation of the Plates of the Muscles.   21

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,  h h, Some rectilineal
ducts which send  oft' the vasa deferentia.  i i, The substance
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
inclosed 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, inclosed in the tu-
nica albuginea.
         EXPLANATION of PLATE XXVIII.
  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  transversale.  s, Exten-
sores  carpi radiales.  t, Latissimus dorsi. u, Anterior edge of
the serratus anticus major, vv, The  inferior part of the  dia-
phragm,  w w, Its anterior edge cut. xx, The  kidneys,  y,
Transversus abdominis, z, Os ilium.
 Inferior Extremity.—a, Psoas magnus. b, Iliacus internus.
c,  The fleshy origin of the tensor vagina femoris.  dd, The os-
sa pubis cut from each other, e,  Musculus pectineus cut from
its origin./, Short head of the triceps abductor femoris cut. g,
The great head of the triceps, h, The  longhead cut.  i, Vastus
internus. k, Vastus externus.   /, Crureus.  m,  Gemellus, n,
Soleus. o, Tibia, p, Peroneeus longus.  q, Peronaeus 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,  ' he
left carotid artery, F, The common trunk which sends off the 
 22   Explanation of the Plates of the Muscles.

 right subclavian and right carotid arteries. G, The carotis ex-
 terna.  II, Arteria facialis, which sends off the coronary arte-
 ries of the lips. I, Arteria temporalis profunda. K, Aorta de-
 scendens. LL, '■ he iliac arteries,—which sends off MM, The
 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 jugularis
 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
 artery. 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, 'I he  cutaneous arch of veins on
 the fore part of the foot.  19, The vena tibialis antica, cover-
ing the artery.  20, The vena profunda femoris, covering the
artery. 21, The upper part of the vena saphena  major. 22,
The femoral vein. 23 23, The iliac veins.  24 24, Vena cava
 inferior. 25  25, The renal veins covering the arteries. 26 26,
 The diaphragmatic veins.
          EXPLANATION of PLATE XXIX.

  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 vertebrse, with their immediate cartilages.
LL,  &c. The five  lumbar vertebrse, with their intermediate
cartilages. M, The os sacrum. N, The os coccygis. 
 
 
      Explanation of the Plates of the Muscles.    £3

  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 occuli ;  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
opthalmic, goes to the orbit, supplies the lachrymal gland,  and
sends branches out to the fore-head 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 mollis,  is spent upon the  internal
ear. '1 he 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 accesorius, which is spent upon the ster-
nocleido-mastoidaeus and trapezius muscles.  12 12, 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. 14 14, The third cervical nerves, which,
after sending  off (15  15, &c.) the phrenic nerves to the di-
aphragm, supply the muscles and teguments that lie on the
side of the neck and top of the shoulder.  16 16,  I he 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.  17 17,  'I he 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 'he
teguments and muscles ef the inferior extremity. 19 19,  The 
24  Explanation of the Plates of the Muscles.

sacro-sciatic, or posterior crural nerve, formed by the two in-
ferior lumbar,  and three superior of theos 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 cceliac
plexus, formed bythe 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 ge-
neration 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 oblong-
ata.  F, The corpus olivare, in the  side of the medulla ob-
longata. G, The medulla oblongata. H, The  medulla spinalis.
  Nerves.—1 2 3 4 5 6 7 8 and 9, Pairs of Nerves.  10 10,
Nervus accessorius, which comes from-—11, 12, and 13, The
three first cervical nerves.
          EXPLANATION of PLATE XXX.

  Figure 1,  Shows the Lachrymal Canals, after the Common
Teguments 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 la-
chrymal 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, b b b b, The tunica choroides adhering to the inside of
the sclerotica, and the ciliary vessels are seen passing over—
c c, The retina which  covers the vitreous humour, d d,  The
ciliary processes, which were continued from the choroid coat-
e e, The iris,  f, The pupil. 
**
 
 
      Explanation of the Plates of the Muscles.  25

  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 attolens palpebral superioris. e, Attollens oculi. f, Abduc-
t°r* 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 which the trochlea or pulley is fixed through
which,—d, The tendons of the trochlearis pass,  e, Attollens
oculi. f, Adductor oculi. g,  Abductor oculi.  h, Obliquus in-
ferior, i, Part of the superior maxillary bone to which it is fix-
ed, 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 superior-
is.  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 fron-
tis cut. M, The crista galli of the ethmoid bone.  N, The
posterior part of the sphenoid  bone.  0, Transverse spinous
process ot 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 of which are
minutely filled  with wax.                             .
   AA, The cut edges of the upper part of the cranium.  B,
                            D 
26  Explanation of the Plates of the Muscek.

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 the ear. f, The cavitas innominata. g, The
scapha. h, The concha,  i i, The parotid gland,  k, A  lym-
phatic 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,
  meatus auditorius, tympanum with its small bones and Eus-
  tachian 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 substance
                     of the Tongue.
  a a,  The tip of the tongue, with some of the papillae mini-
ma, b, The root of the tongue, c, Part of  the membrane of
the tongue, which covered the epiglottis,  d  d, Part of the
musculusUyo-glossus. e,The lingualia. f, Genio-glossus. gg.
Part of the rtylo-glossus. 
 
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