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COMPENDIUM
ANATOMY OF THE HUMAN BODY,
    Intended firinci/ially for the use of Students.
            BY ANDREW FYFE.
IN  TWO  VOLUMES.
         VOL. II.             \

THIRD AMERICAN  EDITION;
                To this Edition is prefixed,
       A COMPENDIOUS HISTOItY OF ANATOMY,
                     AND  THE
          RUYSCHIAN ART AND METHOD
Of making Preparations to exhibit the Structure of the Human Body.
                   ILLUSTRATED
 With a Representation of the Quicksilver Tray and its Appendages,
           Which are not iu the London Edition.


                PHILADELPHIA:
        PUBLISHED BY BENJAMIN C. BUZBY,
             No. 2,  North Thiril-stiect.
1810. 
 
PART IV.
      OF  THE VISCERA,

                 AND

ORGANS  OF THE SENSES.
      OF THE  COMMON INTEGUMENTS.

                  The Cuticle.

  THE Cuticle, Epidermis, or Scarf-Skin,  is a thin se-
mi-transparent insensible Membrane, which covers the
Skin, and adheres to it by small Vascular  Filaments.
  The Cuticle is readily separated from the Cutis by boil-
ing water, or by putrefaction,  and in the  living body,
by the application of blisters.
  It is not every where of the same density, being even
in the Foetus, thickest in the  Palms and Soles ; in which
parts, the thickness is  afterwards much increased by
pressure.
  The External Surface is marked by  Furrows, which
carrespond with those in the Cutis Vera.
  Upon the Surface of the Body it is perforated by the
termination of the Exhalent Vessels,—which throw out
the Perspirable Matter, and which, when  increased, is
considered by most of the modern Physiologists, as for-
ming the Sweat ;—by the ends of the Excretory Ducts,
winch are found in particular parts of the Skin ;—by the
beginnings of  the Absorbents, which  take in certain
Substances applied to the Surface of  the Skin ;—and,
by the different Hairs. 
4
   The perforations, or Pores, are most evident upon the
Palms and Soles,  and upon the  Nose, Ears, and exter-
nal parts of G; neration.
   The Cuticle covers the Skin through its whole extent
excepting under the Nails.
   From the External Surface of the Body, it is refect-
ed inwards,  to line the large Passages ;  as the Alimen-
tary Canal,  the Trachea,  the Urethra,  Vagina, &o.
   In these  Passages, however, the  Cuticle becomes
less uniform in its  texture ;  and  in some Af them, as in
the Stomach, is either a wanting, or is so much chang-
ed in structure, as to have the appearance of being so.
  From  the Surface of the  Cuticle, certain Processes
are sent into the  Skin, which  line the Passages by
which the Cutis is perforated.
  Many opinions  have been  advanced concerning the
origin of the Cuticle : the latest and nvost probable is,
that it is formed by a condensation of the Corpus Mu-
cosum, or by the Extremities of Excretory Vessels ;—
its  density,  however, is such, that no  vessels can  be,
traced in it, either by the Eye or by the assistance of
glasses.
  The Cuticle serves to protect the  sensible parts un-
der it ; and regulate the proportion of the Fluids thrown
out or taken in  by the Surface  of the Skin ;—particu-
larly to prevent too great a degree of evaporation.

                  Corpus Mucosum..

  The Corpus Mucosum has been commonly called Pete
Mucosum, from the supposition  that it  is formed of a
Mv.;o:is Net work,  and is situated  under the Cuticle
v inch it connects to the Cutis Vera.
  It is composed of the  terminations of extremely
minute Vessels passing between the  Cutis and Cuticle,
which are surrounded by a Mucilaginous or Viscid sub-
stance,  properly called Corpus Mucosum
  It is the chief cause of that variety of colour  which
characterises the natives of.different climates, and dif-
ferent people ofthe same climate, being white, or rather
of a light-grey semi-transparent colour in the European,
black in the Ethiopian, brown in  the  Asiatic, &c.
  L i» tiiicker  and  stronger in the Negro  than in the 
                          5
 white person, and can be readily separated in  the  for-
 mer into two  Layers.
   It covers every part of the Surface of the Cutis, ex-
 cepting below the Nails,  where it is a wanting ; and is
 of such a light colour in the  Palms and Soles of the
 Negro,  as to  have been supposed by  some authors to
 be deficient there also.
   Its origin has not  yet  been sufficiently  ascertained,
 nor Is it fully  determined what  particular purposes it
 serves.
   Among other purposes, however,  it contributes to
 preserve the structure of the tender Vessels, Ducts,  and
 Papill*, placed between the Cutis and Cuticle ;  and
 in the Negro, it  is  supposed to  serve as  a defence a-
 gainst the heat of the climate,  by preventing the rays
 of the Sun from penetrating the Skin.

                     Cutis Vera.
   The Cutis Vera, or Skin, properly so called,  lies im-
 mediately under the Corpus Mucosum, and gives a ge-
 neral covering to the wh  le Body.
   It is formed of Fibres intimately interwoven, and run-
 ning in  every direction, and is so plentifully  supplied
 with Nerves and Blood-vessels, that the smallest punc-
 ture cannot be made in any part  of  it, without occa-
 sioning pain and bringing Blood.
   The Blood-vessels  of the Cutis are so numerous, as
 to appear to form  almost the  whole  of its Substance,
 and are of such a  size as to be readily injected-
  It is strong and elastic, and may be elongated in e-
 very direction, after  which it  recovers its former di-
 mensions.
  It forms  the body of the Skin,  and is  that  part in
 Quadrupeds of which Leather is made.
  The outer part of it is dense and firm, the inner loose
 and gradually degenerating into the  common  Celhilar
 Substance.
  It is thicker and looser on the posterior than on  the
 anterior part of the Body, and thicker and firmer in  the
 Palms and Soles than in the  other parts of the extre-
mities.
  The colour of the Cutis  also differs in different parts
of the body, in proportion to  the quantity  of Blood in
                          A  2 
6
the extreme Vessels, and to the thinness of the Cuti-
cle.
  At the edge of the  Eye-lids, the red part of the Lips,
and margin of the Anus,  the Cutis becomes so immedi-
ately and remarkably thin, as to appear to be lost.
  Upon the Surface of the Cutis, small Eminences are
observed, called Papilla, Papilla Nervosce,  and Papil-
la Pyramidalcs ; the  term being borrowed from the Pa-
pillae of the Tongue, which  were first discovered, and
to which the name is most applicable.
  They are considered as forming the Organ of Touch,
from their being extremely  sensible ;  and from  their
being  very Vascular, they  are  also regarded  as fur-
nishing a passage to part of the Perspirable Matter.
  The Papilla are most evident in the Palms and Soles
where  they are placed in double rows upon the ridges,
which on the points of the Fingers and Toes, generally
run in a somewhat spiral and parallel direction.
  The  Ridges are supposed to defend the Papillae, and
to increase the Surface for Perspiration.
  In some places, as in  the red  part of the Lips, the
Papillae are  termed  Villi, from their  resemblance to
the pile ofVelvet.
  Various kinds of folds are observed in the Skin ; some
depending upon the form of the Cellular Substance, as
in the Hips ;  others  on  Muscular Contraction, as in
the  Fore-head ; and others on Articular Motion,  as at
the Joints of the extremities,—particularly those of the
Fingers and Toes ;—and these folds are  thinner than
the  rest of the Skin,  to allow easy motion.
  In an inflamed Skin, as in the case of Small-pox,  a
Reticular Texture of Vessels is observed, which can be'
easily injected,  and has been considered by some as the
Corpus Mucosum, and by others as an additional Cuti-
cle ;—but no such appearance  is to be  met with in the
sound  Skin.
  The  Cutis Vera serves to  cover and give form to the
Body,  it unites the different parts, and  defends them
from injury.  It forms the external Organs of Sensation
or of Touch, and gives passage to the Fluids which are
Perspired or Absorbed. 
      APPENDAGES  OF THE  SKIN.


                       Nails.

   The Nails were formerly regarded as a continuation
 of the Papillae of the Cutis',  but are now more generally
 considered as a continuation of the Cuticle.
   They are removed  along  with it by boiling water, or
 by maceration.
  " Like the Cuticle also,  they are insensible,  are re-
 newable after having been separated, and have no evi-
 dent Vessels.
   Thev  differ  from it, however,  in  structure, being
 formed of Plates, and these of Longitudinal Fibres, which
 are  closely compacted.
   They begin by a square root, a little  before the last
 Joint of the Fingers and Toes.
   When separated from the  Skin, they are transparent
 like Horn, but are coloured in the living Body by the
 Vessels of the Cutis, to which  they adhere, and  from
 which they derive their nourishment.
   They are fixed at their  roots to a semilunar fold of
 the Cutis,  and are there covered  by a reflection of the
 Cuticle,  which firmly adheres to them.
  They grow from the roots, and not from the points.
  The nails strengthen and defend the ends of the Fin-
 ders and Toes,  and thereby serve as Buttresses.
  In the Fingers they increase the power of apprehen-
 sion, being useful in laying hold of minute objects.
                     Hairs.
  The Hairs arise by roots or bulbs, which are situa-
 ted in the Cellular Substance under the  Skin.
  The Bulbs are of various shapes in different parts of
 the Body, and hate Blood-Vessels dispersed upon them
for their nourishment.
  Each of the Bulbs has to Membranes, or  Capsules,
 containing  an Oily Fluid  between them,  which gives
 colour to the Hair, and for want of which, as on ad-
 vanced life, or in certain diseases, the hair is supposed
 to change its colour, and become white.  It may be re-
                   A 3 
8
marked,  however, that the Hair, after being cut  off'
continues uniformly to preserve its colour.
  The body of the Hair consists of smaller hairs inclo-
sed in a Membrane, and is somewhat of the nature of
the Nails  Like them also, it grows only from the root.
  The use of the Hair is not yet fully known.—It serves
in general for  the ornament, warmth, or protection of
the different parts on, or near which it is placed.

   Sebaceous Ducts or Follicles, and Miliary Glands.
  The Sebaceous Follicles derive their  name  from the
Fluid they contain becoming like Suet, after acquiring
a certain degree of consistency,  or being inspissated by
stagnation.
  They are seated under the Cutis, and are  found in
greatest  abundance in those parts which  are exposed
to the air,  or to attrition ; as in  the Nose, Ears,  Nip-
ples,  Groins,  and external parts of Generation.
  The Sebaceous or Miliary Glands, are so called from
their  contents, and from their resemblance  to Millet
Seeds, and are seated in the Axilla.
  Other Miliary  Glands are described by Authors as
being placed under the Skin over the  whole surface of
the Body, and as serving for the secretion of Perspira-
ble Matter ; but they are not demonstrable to such a
general extent; and the Sweat is considered as being
derived from another source.
  These Follicles and Glands secrete  a fluid which serves
to lubricate the Skin, and defend it  from the inclemen-
cy of the weather, or from the effects of friction.

  Membrana Cellularis, or Tela Celluloisa, or Reticular,
                 or Cellular Substance.
  This is generally considered as one of the Integu-
ments,  though common to these and to the other parts
of the Body.
   It is composed of a fine web,  formed of many Mem-
branes joined  irregularly together,  and these made up
of Cells, which communicate freely with  each other
wherever they are found.
   It is very elastic, may be drawn out to a considerable
extent, after which it suddenly recoils, and may be con-
densed or compacted to a great degree. 
9
  It lines the Skin, covers the Muscles in general, and
enters in between their dif/erent Fibres;—is an univer-
sal covering to all  the other parts, and even enters into
the composition of almost every one of them.
  It is thickest where the  parts are most  exposed to
pressure,  as in the Hips. Palms, and Soles.
  The different Cells of which it is composed, are con-
stantly moistened by an  Interstitial Fluid, and in many
parts of the Body are filled with Fat.
  It has little or no sensibility, can be handled freely,
or cut or punctured without giving pain.
  It serves to connect parts to each other,—but so as
to prevent  them  from  growing together;—it covers
them, supplies'them with sheaths to move in, and con-
tains the Fat.
      Corpus Adiposum,  Adeps, Finguedo,  or Fat.
  The Fat is lodged in the common Cellular Substance,
l-.u* wiihout communicating with it, and is  made up of
\i;.:.scs composed of small Vesicles containing the Fat,
and these are surrounded by  a net work of Blood-ves-
sels,  from which the Fat is supposed to  be secreted,
without the intervention of Glands.
  The resides are not found to have any communication
with each other, nor have  any Execretory  Dvicts yet
been  perceived in them,—the I at being supposed to
transude from the Cells.
  It is of different consistency in different parts of thebody:
In the living Body it is generally fluid, though in some
parts it approaches to a solid, and is altogether of this
nature in  the dead Body.
  In the Bones it forms  the  Marrow,  which has been
formerly described.
   The I at is chiefly situated immediately under the
 Skin, and covers almost the whole Surface of the Body.
 It is  also  found between the different Muscles and Fi-
 bres of Muscles,—within the Orbits, and in the Cheeks,
 in the Substance of the Mammae, and about the Heait.
   It abounds in the Abdomen, about the Kidneys, Loins,
 Omentum, and  Mesentery ;—and in the Joints it forms
 the Substances  called  Glands of the Joints,  already
 mentioned.
   The  Fat is a wanting in the Scrotum, Penis, and Eye-
                           A 4, 
10
 Lids,  and is fuund only in  small  quantity in the Fore-
 head,  or about the Joints, where,  from its  bulk,  it
 would have been inconvenient.—It is also a  wanting in
 the Substance of the Vicera situated in the great Ca-
 vities of the Body ; as the Brain, Lungs, Liver, Spleen,
 Kidneys, &c.
   The Fat serves to lubricate every part of the Body to
 which it is connected, and facilitates the action of the
 Muscles.  It fills  the Interstices, so as to give form
 and smoothness, and guard against pressure- It serves
 also as a reservoir of nourishment.
                Panniculus Carnosus,
           Described by the Ancients as an
                Additional Covering.
  This is a general Covering found in the Quadruped,
and formed by  a  thin  Subcutaneous Muscle, which
serves to agitate the Skin.
  It is found only in certain parts of the Human Body ;
as in the Forehead, where it is formed by the Occipito-
Frontalis Muscles; and in the Neck,  where it is form-
ed by the Platysma Myoides.
OF THE  BRAIN.
  The term Brain is applied to the whole of that Mass
which, with its surrounding Membranes,  fills the Ca-
vity of the Cranium  j and is larger in Man, in propor-
tion to the size of the body, than in any other animal.
  The Membranes of the Brain were called Meninges
and Maters by the Ancients, from an idea that thev
gave birth or origin to all the other Membranes of the
Body.
  They consist of the Dura Mater, Tunica Arachnoidea
and Pia Mater-
  The Dura Mater, named  from  its being of a firmer
texture than the other  two  Membranes,  incloses the 
II
Brain and all it s Appendages, and lines  the different
parts of the  Cranium.
  It is composed of one Membrane, which, in several
parts, is div isible by .maceration into two, or even more
layers of Fibics.
  The texture of the Dura  Mater is very dense.   It is
the thickest and strongest Membrane of the  Body, and
is composed of Tendinous-like  Fibres, which  have a
shining appearance, particularly  in its inner Surface.
In many parts these Fibres run in a variety of direc-
tions, and decussate each other at different angles.
  The Dura Mater adheres every where to the Surface
of the Cratuum, in the same manner as the Periosteum
adheres to the Bones  in the other parts of the Body ;
but it is more firmly connected at the Sutures and Fo-
ramina than elsewhere ; and so much  more  firmly in
Child-en than in Adults, that in separating it from the
Cranium,  it  is apt to bring along with it some  of the
Fibres of the Bone to which it is attached.—In  the A-
dult, the separation of the Bone from the Membrane is
less difficult, in consequence of many of the Fibres be-
ing obliterated.
   The inner Surface of the Dura Mater,  which is re-
markably smooth, is in close contact with the  Brain, but
adheres only where the Veins go into the Sinuses,—and
is lubricated by a Fluid discharged through its Vessels,
which guards the Brain from danger, according  as  it
may be affected by the different states of Respiration.
   The Dura Mater serves as a defence to the Brain, and
supplies the place of a Periosteum to the  inside of the
Bones of the Cranium,  giving nourishment to them,—
as is evident from numerous drops of blood  which ap-
pear after removing the Skull-cap.
   From the inner side of the Dura Mater, Processes are
sent off, which divide the Brain into certain  parts, and
serve to keep it steady, viz.
   I. The Fai.x, Superior Longitudinal Process,  or Sep-
tum Cerebri, which is formed by a doubling of the Du-
ra Mater, and is situated between the Hemispheres of
the Brain.
   It begins at the  middle of the Sphenoid, and  Crista
 Galli of the Ethmoid Bone, and runs along the upper
 and middle  part of the Head, adhering first to the Fron- 
12
 tal, then to the joining of the Parietal, and afterwards
 to the middle of the Occipital Bone.
   In its passage it becomes gradually broader, extends
 from the Cranium to near the Corpus  Callosum, and
 terminates behind in the middle of the Tentorium.
   It runs from behind forwards in a straight direction,
 and has some resemblance in shape to a Sickle or Scythe,
 from which circumstance it has obtained  the name of
 Falx.
  Between the under edge of the Falx and Base of the
 Cranium, there is a large Space, of an oval form, occu-
 pied by that part of the  Brain which is common to the
 two Hemispheres.
  The Falx supports the Tentorium, and prevents the
 two sides of the Brain from pressing upon each other.
  II.  The Texi oun m Ceuebelli.op TransverleSep-
 tum, or Lateral Processes of the Dura Mater.
  The Tentorium  is continued laterally from the Falx,
 is connected behind to the inner Transverse Ridges and
 Grooves of the Occipital Bone, and at the fore and outer
 Edges, to the Ridges and great Angles of the  Temporal
 Bones, and terminates at the Posterior Clinoid Process
 of the Sphenoid Bone.
  Between the middle and inner edges of the Tentorium
 and Posterior Clinoid Process of  the Sphenoid Bone,
there is a large Notch,  or Foramen Ovale,  where  the
Brain and Cerebellum are united, or where the  Tuber
 Annulare is chiefly situated.
  The  Tentorium keeps the Falx tense and forms a. floor
 or vault over the Cerebellum,  which prevents the Brain
 from pressing upon it.
  III.  The Falx  Minor, or Septum Cerebelli, which is
placed between the Lobes of  the  Cerebellum.   It de-
scends from the under and back-part of the r~lx in the
middle of the Tentorium, adheres to the inferior Lon-
gitudinal Spine of the Os Occipitis, and  terminates in-
sensibly at the edge of the Foramen Magnum of that
Bone.
  Besides ihe Processes of the Dura Mater already de-
scribed, there are four of inferior consideration, two of
which are situated at the sides of the Sella Turcica and
two at the edges of the Foainir.a Lacera.
  Several other Processes pass out at the different open- 
13
ings of the Cranium, to be connected to the Pericrani-
um, or to accompany the Spinal Marrow and Nerves \f
These of the last description shall be afterwards taken
notice of.
  The Arteries of the  Dura Mater are derived  partly
from the external Carotids* and partly from the internal
Carotids and Vertebrals.
  The Veins of this Membrane are of two kinds.   One
set of them, like  the Veins in other parts of the Body
accompany the Arteries ;—the others are termed Sinuses
and differ  from Veins  only in this,  that they are of a
triangular figure, and inclosed in a doubling of the Dura
Mater, which is so tense over them, as to become affect-
ed  in consequence  of  the pressure ..from surrounding
parts.
  In the bottom  of the Sinuses  are small Transverse
Chords termed Chorda Wilisii, which may add a little
to their strength, and  assist  in preventing them from
being too much distended.
  The Sinuses serve to carry the blood from the Brain,
and convey  it to the Veins of the Neck, for which pur-
pose they are properly fitted,  their covering from the
Dura Muter giving them  strength, and their frequent
communications preventing congestion.

             The Principal Sincses are,
  I. The Superior Longitudinal  Sinus, which begins at
the Crista  Galli of the Ethmoid Bone, runs along the
upner edge of the Falx, becomes gradually larger in its
progress, and terminates in the Lateral Sinuses.
  II. The  Torcular  Herophili. or fourth  Sinus of the
Ancients ; the term  Torcular is  applied to it from the
supposition that the blood  is squeezed in that Sinus as
in a Wine press.— It is chiefly formed of the Vena Ga-
leni, runs between the  Falx and Tentorium, and termi-
nates with  the former  Sinus  in  the beginning of the
Lateral Sinuses.
  III.  The  two Lateral Sinuses, which are  formed by
the Longitudinal and Torcular Sinuses, run in depres-
sions of the Occipital and Temporal Bone.-, first trans-
versely, then in  a winding direction downwards, and
terminate at the Base of the Cranium, in the beginning
of the Internal Jugular Veins. 
14
  Besides the Sinuses mentioned above, several others
Of less consideration will be pointed out in the particu-
lar  description of the Veins.
  The Nerves of the Dura Mater are so very minute, that
they have not as yet been distinctly traced, and it is
found to possess very little sensibility in the sound state.
  Upon the side of the superior longitudinal Sinus, and
contiguous parts of the Brain, there are numerous small
Granulations, of a whitish colour, called Glandule Pa-
chioni
  Besides the Granulations, there are others of the same
nnme.of a Fleshy Colour, situated on certain parts of the
outer surface of  the Dura Mater, and frequently pro-
jecting so much as to form deep pits in the Scull
  The nature of these Granulations is still unknown.—
By some they have been supposed to belong to the Lym-
phatic System.
  The Tunica Arachnoidea, named from its cob-web ap-
pearance, is  an exceedingly thin, tender, and transpa-
rent membrane, in which no vessels have been hitherto
observed.
  It is spread uniformly over the surface of the Brain,
inclosing ail its Convolutions, without insinuating itself
between any of them.
  At the upper part of the Brain, it adheres so closely
to the  subjacent Coat by line Cellular Substance, that
it can  scarcely be separated  from it; but in diffident
parts of the Base of the Brain, particularly  about the
Tuber Annulare and Medulla Oblongata, it is merely
in contact with the Membrane under it, and may readily
be raised from it by the assistance of the Blow-pipe.
  The Tunica Arachnoidea, like the Cuticle, covers and
defends the parts under it.
  The Pia Mater, named from its tenderness, is some-
what of the nature of the former covering, but is ex-
tremely Vascular.
  It covers the Brain in general, enters double between
all its Convolutions, and lines  the  different Cavities cal-
led Ventricies.
  It serves to contain  and support the  Vessels of tlie
B. ain, and aliovs them to divide into such minute parts,
as to prevent the Blood from entering the  tender sub-
stance of this Viscus with too great force. 
15
  The Arteries of the Pia  Mater, are  the same  with
those of the Brain, and  are derived from the Internal
Carotids and Vertebrals.
  The Veins differ in no respect from those of the other
Viscera, excepting in this, that they do not accompany
the Arteries.
  The Brain is divided into Cerebrum, Cerebellum, Tuber
Annulare and Medulla Oblongata.

                     Cerebrum.
  The Cerebrum is situated in the upper part of the Cra-
nium, which it completely fills.
  It is divided into two halves, termed Hemispheres,
which are separated from each other by the Falx.
  Each of the Hemispheres is of an oval form, or they
somewhat resemble an egg cut into two  longitudinal
halves.  The inner sides are flat,  the" upper and outer
parts convex, and the under Surface irregular.
  The under Surface is  divided into two Anterior, two
Lateral, and two Posterior Lobes, or Processes.
  The Anterior Lobes are situated in the fore-part of the
Base of the Cranium.
  The Lateral or Middle lobes, are lodged in the Fossae
formed by the Temporal and Sphenoid Bones.
  The Posterior Lobes are placed over the Cerebellum,
and are separated from it by the Tentorium
  Between the Anterior  and Lateral Lobes, there is a
Furrow formed by the Anterior Clinoid Processes of the
Sphenoid Bone, which  has been termed Fossa, or Fis-
sura Magna Sylvii.
  The Surface of the Brain  is  divided into many turn-
ings or windings, termed Circumvolutions, which run in
various directions, and are of different sizes and lengths
on different  parts of the Bi-ain.
  The Circumvolutions are  every where  connected to
the  Pia Mater by an infinite number of small Vessels,
—called by  Ruysch, Tomentum Cerebri—which run in-
to the substance of the Brain ;  as may be readily seen,
upon separating the Circumvolutions a little from each
other.
  Between the Hemispheres a white Substance is ob-
served, called Corpus Callosum, from its being  a little
firmer than  the rest of the  Brain.—It goes across the 
16
Brain, under tne Falx, and is merely a continuation of
Medullary Substance, running horizontally, and joining
the two sides of the Hemispheres to each  other.
  In the middle of the Corpus Callosum there is a lon-
gitudinal Raphe, with a Medullary Cord on each side,
from  which  many  transverse  streaks issue.   These
Cords, like the Corpus Callosum itself, become gradu-
ally broader towards the posterior extremity.
  An horizontal  Section, a  little above  the middle
height of the Brain, or upon a level with the Corpus
Callosum, shews the  division of the  Substance of the
Brain into outer or  inner, or Cortical and Medullary
parts.
  The outer Substance  is termed Cineritious, from its
being of a greyish or ash colour,—though a little tinged
with brown ;—and Cortical, from its surrounding the in-
ner part of the  Brain, as the Bark does the  Pith of a
Tree.
  It is termed by some Authors Glandular, and by o-
thers Secretory, from a supposition that a Fluid was se-
creted in it.
  The Cineritious Substance covers the Bratn in general,
and enters deep between its Convolutions, of a soft
consistence, and composed of numerous small Vessels
carrying red  Blood  ; but it is uniform, and without any
appearance of a Fibrous texture.
  The inner Substance  is termed White or Medullary,
and is considered as giving origin to the different Nerves.
It has been by  some called Excretory, having been sup-
posed to be formed of hollow Tubes continued from the
Vessels of the Cortical  part ;—but no Cavities have
ever been observed  in the soft Fibres of which it is
composed.
   It is  greater in quantity, and somewhat firmer in tex-
ture, than the Cineritious Substance, and is so intimate-
ly connected as to appear to be a  continuation of it___
The soft Fibres or  streaks of the Medullary Matter,
run in general  in a  parallel and transverse direction.
   In many parts of  the Cineritious Substance, Medul-
lary Matter appears ; and, on the contrary, in different
 parts of the Medullary  Substance,  Cineritious Matter
 is found ; the two being frequently blended together in
 the form of streaks.  See Monro on Nervous System. 
17
      The Centrum Ovale of Vieussetts.   This is the Medul-
    lary Substance of the Brain, forming a kind of Nucleus,
    which is seen after removing the Cineritious Substance,
    and all the Medullary parts mixed with it, which lie
    between the Cortical Convolutions.
      To obtain a proper view of the  Centrum Ovale, the
    Nucleus ought to be cut  in such  a manner as to pre-
    serve the Corpus Callosum, and the same convexity
    with that of the general convexity of the Brain.
      The Centrum Ovale  forms an arch or  roof over the
    two Lateral Ventricles ; and the under part of this roof
9   which is smooth  and uniform, constitutes the upper
    part of these Ventricles.
      Vieussens considered the Centrum Ovale as the great
    Dispensatory of the Animal Spirits.
      The Ventricles of the Brain are four in number, two
    of which are called Lateral.
      The four Ventricles have their  sides  contiguous to
    each other, are ehiefly  formed of Medullary Matter,
    and are lined with  a continuation of the  Pia Mater,
    which differs from that covering the  exterior surface of
    the Brahl, in having fewer vessels dispersed upon it.
      They are  constantly moistened  by a  Fluid, which
    prevents their opposite sides from  adhering  to  each
    other.
      The use of the Ventricles,  like many other parts of
    the Brain, is still unknown.
      The Lateral, formerly called Superior Ventricles, are
    situated in the  Hemispheres, one in each, and run ho-
    rizontally in the same direction with the Hemispheres
    themselves.
      They are of an irregular form, lying under the  Cen-
    trum Ovale, and have each three winding corners,  com-
    pared to Ram's Horns, which are therefore called Cor-
    nua.
      The Anterior Cornua are separated only by the Septum
    Lucidum.
      The Posterior Cornua, called also Digital Cavities, are
    at a considerable  distance  from each other, but ap-
    proach nearer at their pointed extremities ; while the
   inferior Cornua, the  beginning of  which  is seen, run
    downwards and forwards,  and terminate in the Lateral
    Lobes of the Brain. 
18
   In each of the Posterior Cornua there is an Elonga-
tion,  which terminates in a  point, and is called Ergo,
by the French, from its resemblance to the Spin  of a
Cock ;  or Hippocampus Minor, from its similarity to,
and connection with, the substance termed  Hippocam-
pus Major.
   In the fore-part,of the bottom of the Lateral Ventri-
cles, are two large Eminences, called Corpora Striata,
which become gradually narrower,  and  recede from
each other at their posterior extremities.
   The Structure of these is Cineritious externally, and
mixed with Medullary Striae within, some of which form
large  Transverse Medullary  Arches, and others run
more  in a straight direction.
   Between the posterior parts of  the Corpora Striata,
are situated the Thalami Nervorum Opticorum, which
have a roundish form and  Medullary Surface,  and are
of a Striated appearance within, but the Striae are less
distinct than in the Corpora Striata.
   Upon tiie Surface of these Bodies, there are small
Eminences or Tubercles, some of which  are placed up-
on their superior, and others upon their inferior extre-
mities.
  The inner parts  of the Thalami  are flat and contigu-
ous, and above  they are so closely connected as to form
one continued Surface, called Commissuri Mollis of the
Optic 1 iialurni
  The posterior parts of the  Thalami turn downwards
and outwards, after which they are elongated, to form
the two white Cords, called Tractus  Optici.
   In  the Groove between the Corpora Striata and Tha-
lami,  there  is a Medullary Band  on each side, called
CentrumSemicii culare Geminumo/"Vielssens,or T<enia
Semieirculurit tf litL.LL.nii., or simply Taenia.
   0\er  the   Tliala.ni  is placed the  Choroid Plexus,—
named from its being composed of a Chorus of Vessels
and Membranes.  It is a tine Vascular Web, consiting
of small ramitications of Arteries and Veins, connected
by Hie Pia  ?/Iater, and spread'upon the  Surface ol the
Tliahuui, and some of the adjacent parts.
  Tue Choroid Plexus frequently contains numerous
rou.id Gi.obu;es, resembling Hydatids which have been
considered by some Authors  as L) mphatic  Glands. 
19
     Under the Raphe of the Corpus Callosum, is placed
   the Septum Lucidum, which, when viewed laterally, is
   observed to be broad before, curved at its edge, and
   to become gradually narrower towards its posterior ex-
   tremity.
     It is connected above to the Corpus  Callosum, be-
   low to the Fornix,  and  forms a distinct partition be-
   tween the lateral Ventricles.
     It is formed of two  Cineritious and Medullary La-
   mina:, more or less separated from  each other at their
   fore-part, by a small  Cavity, called Fissure, or Fossa
   of Sylvius, or  Sinus of the  Septum Lucidum, which,
   however, does not communicate with the Lateral Ven-
   tricles, though  in some subjects it reaches a consider-
   able way backwards, and, as well as the other Cavities
   of the Brain, has been found full of water in  Hydroce-
   phalous cases.
     Under the Septum  Lucidum is placed the Substance
   which has been  compared in shape to a  Vault by the
   Ancients, and from that has obtained the name of* For'
   nix.
      The Forrix is merely a continuation  of the  Corpus
   Callosum, and forms a sort of hollow Ceiling, with four
   Pillars called Crura, or Cornua, from their winding di-
   rection, of which there are two anterior and two pos-
   terior.
     The two Anterior Crura are short, run close together,
   and become enlarged at their inferior parts  'The two
   Posterior Crura are  long, considerably distant from each
   other, and form  Curvatures which correspond with the
   course of the  Inferior Cornua of the  Lateral Ventri-
   cles.
     That part of the  Crura Fornicis lying in the Inferior
   Cornua of these Ventricles, forms thin oorders, getting
   the names of Corpora Fimbriata ;  but, according to the
   Vic D'Azyu, they are more property  termed  Tania
'   Hippocampi, from being united with the great Hippo-
(,  campus.
>j    'I he body of the  Fornix is narrow anteriorly, and be-
   comes considerably broader behind, where it u incorpo-
   rated with the Corpus Callosum.
     The under Surface of the posterior part of the body
   of the Fornix, is impressed with numerous transversa
        v 01..  11 ■              u 
20
and oblique Lines, which have been called Psalterium,
or Lyra, from some resemblance they bear to the an-
cient musical instruments of these names.
  The body of the Fornix is  joined above to the Sep-
tum Lucidum  : below  it is  connected to the 1 halami
Optici,bya Vascular Membrane, called Tela Choroidea,
which spreads over the Thalami, and unites the Cho-
roid Plexus of the Lateral Ventricles.
  The Pedes Hippocampi,  Great Hippocampus, or Cor-
nua Amvionis,—named from  a supposed resemblance
to these parts,—are two Medullary  Eminences,  which
arise from the sides of the posterior extremity  of the
Corpus Callosum, and are situated in the inferior Pro-
longations of the Lateral Ventricles.
  They run through the whole extent  of the Prolonga-
tions,  first behind, then at the outer part of the poste-
rior pillars of the  Fornix, and are so intimately connect-
ed with them, that they have been considered by some
Authors as forming part of the  Pillars themselves.
  They are small at their origin, from which they con-
tinue to increase to their farther extremity.
  Like the greater part of the Ventricles, they are co-
vered externally with a Medullary Lamina ;—internally
they are found to consist of Medullary and Cineritious
Laminae, of a convoluted appearance.
  At the inner edge of the Pedis Hippocampi, there is
a plaited, serrated, or indented Margin, which, in the ge-
nerality of Quadrupeds, is much larger,  in  proportion
to the size of the  Brain, than it is in  Man.—The resem-
blance, however,  to the human kind, in  the structure
of this particular  part of the Brain,  is more striking in
the Ape than in any other Quadruped.
  In the bottom of the  Lateral Ventricles, behind the
anterior Crura  of the  Fornix,  and before the mee'.ing
of the Choroid Plexuses of these Ventricles, below the
anterior part of the  body of  the Fornix,  and over the
forepart of .the third Ventricle, there is a H»ie, of an
ccal form, by which the  Lateral Ventricles communi-
cate freely with  eacli  other.    See Monro's Obs. on
Nerv. S.xt. 1T83.  and Treatise on the Brain, 1797.
  After dividing  and turning buck the Fornix, another
communication from the above passage is found, called
Foramen Commune Antarrut,  Vul'ja,  or Iter ad Irfundi- 
21
bulum ; but properlv, Iter ad  Tertium Ventriculum, or
Passage to the third Ventricle.
   Between the Commissura Mollis of the Optic Tha-
lami, and  Substance called Pineal  Gland,  there is  a
small passage termed Anus, or Foramen Commune Pos-
terius, which has been  supposed by  some  Authois to
form a communication between the  bark-part of the
third Ventricle and  Lateral Ventricles; but it is com-
pletely shut up by the Tela Choroidea, and  also by the
Fornix, which adheres closely to this membrane.
   The Third Ventricle is in form of a deep Fissure, pla-
ced between the inner ends of the Thalami  Optici, ha.
vingfhe Commissura Mollis of these Thalami situated
above, and the Crura Cerebri below, and the bodes of
the Thalami on each side.
   The Infundibulum is a  passage of considerable size,
of a Cineritious and Medullary structure, which leads
downwards and forwards,  gradually  contracting, and
becoming solid  at its  under end, where it  terminates
in the Glandula Pituitaria, and thus, contrary to the o-
pinion of the Ancients, preventing the passage of any
Pituitous Fluid from it to the Nose.
   The Glandula Pituitaria is of an oval form, about the
size of a Field-bean, lodged  in the Sella Turcica, and
surrounded by a doubling of the Dura Mater.
   On the outside it is of a brownish colour, being form-
ed of Cineritious Matter ; it is whiter within, where it
is mixed with Medullary  Substance.
   The Glandula Pituitaria  was formerly supposed to
absorb a Fluid  from  the Infundibulum, and  transmit it
to the  Nose.   It has been already mentioned, however,
that the Infundibulum  is impervious ;  and the real use
of this Gland, as well as  of the other Tubercles of the
Brain,  seems still unknown.
   At the fore-part of the  third  Ventricle,  and  imme-
diately before the Anterior Crura of the Fornix, there
is a  white  .Medullary  Curd, which  runs transversely
through the Corpora Striata, and has the name of Com-
missura Cerebri Anterior.
  At the back-part of the third  Ventricle,  and under
the .oot of the Pineal Gland, there is another Cord si-
milar to the former,  but siiorter, called Commissura Ce-
rebri Postei ior.   The Commissura Cerebri assist in uni- 
                         22
ting the two sides of the Brain to which they are fixed.
  From the under and back-part of the third Ventricle,
there is a Passage which leads to the fourth, under the
name of Iter ad §hiartum Ventriculum Canalis  Mcdius,
or Aquxductus Sylvii.
  After the posterior part of the Fornix, and  the Tela
Choroidea to which it adheres, have  been removed,
there appears at the back-part  of the third Ventricle,
behind the Thalami,  and over the  Iter a Tertio  ad
Qiiartum Ventriculum, the Nates and Testes, or Tuber-
cula Qjiadrigemina, and Pineal Gland.
  The Nates, or Tubercula §>uaJrigemina Anteriora, are
placed uppermost, and are of a rounder form than the
Testes,or Tubercula ^uadrigemina Posteriora,—which lie
immediately below the former.—The Testes are broad-
er from one side to the other than from top to bottom,
and of a white colour.
  A longitudinal Section shews the Tubercula to  be
covered externally with  a thin Medullary Lamina, and
to be  Cineritious within.
  In Man they are more nearly or an equal size than
in Quadrupeds, as in the Ox, Sheep, &c. in which the
Nates are large, round, and  of a brown colour, and the
Testes small and long.
  Over the Nates and  under the back-part of the For-
nix is placed a small body, of  a Cineritious nature, a-
bout the size of a Garden-Pea, and of a Conoid figure,
called Glandula Pinealis, from its resemblance in shape
to a Pine or Fir Cons.
  In consequence of being always present, and seldom
found in  a diseased state, it has  been celebrated by
Des Cartes, as being, according to his supposition,
the Seat of the'Soul.
   The Pineal Gland is  fixed at  its root to the  Commis-
sura Cerebri Posterior, and  sends  out two  long Medul-
lary Peduncles, or Foot-stalks to be fixed to the upper
and inner side of the Thalami  and to the anterior Cru-
ra of the Fornix.
   Near, or in the Substance of the Pineal Gland, small
Calcareous Concretions are sometimes found, called by
Soemmering, Acervulus Cerebri, from their  being  ge-
nerally found collected in a heap.
   They do not appear to be  the effects of disease ;  nor
are they met with till after the age of Puberty. 
23
                     Cerebellum.
  The Cerebellum is situated in the inferior Fossae of the
Occipital Bone, under the Posterior Lobes of the Brain,
and is separated from these Lobes by the Tentorium.
  It is somewhat of a roundish  form,  though a little
broader from one side to  the other  than from before
backwards   It is only about a fifth or sixth part of the
size of the Cerebrum, and  much simpler.
  It is divided behind by the Fal\ Minor into two Lobes
or Hemispheres, but has no separation above like the
Brain.
  Its Surface is divided into numerous Circumvolutions,
which form arches,  decussating each  other in many
parts, at sharp angles.
  The Circumvolutions run chiefly in a Lateral direc-
tion, and are formed of Laminae,  with  deep Sulci be-
tween them, into which as in the Brain, the Pia Mater
insinuates itself, which may be readily seen by  making
a puncture into the Arachnoid Coat, and blowing  in air
till it distend the Cellular Substance, and separate the
Coats from each other.
   It has two middle Eminences, called  Appendices Ver-
nniformes, from their resemblance to Earth-worms, one
of which is situated anteriorly and superiorly, the other
interiorly and posteriorly.
  Each of the Lobes of the Cerebellum is  again divid-
ed into Monticuli or Lobules, which have different names
according to their relative situations, connections with
other parts, &c. They vary a little in the different  Sub-
jects, but are best distinguished  from the direction of
their Convolutions.
  The Substance of the Cerebellum  consists of Cineri-
tious and Medullary Matter, as in the Cerebrum ; but
the Cineritious hears a greater proportion to the Me-
dullary in the former than  in the latter.
   When the Cerebellum is cut in a vertical direction,
the Medullary part is then found to bear a striking re,
semblance  to the branching of the shrub called Ar-
bor Vita, from which  circumstance it has obtained the
name of this shrub.
   When cut in slices nearly parallel to the Base of the
Brain, the Medullary Substance  appears  in Luininx,
                       B  2 
24
 corresponding to those of the Surface of the Cerebel-
 lum ; and when cut to a considerable depth, there is a
 Centrum Medullare uniting the Lateral Lobes as in the
 Brain.                                     ^   .
   Between the  Cerebellum ; the under part of the Tu-
 her Annulare, and upper part of the Medulla Oblonga-
 ta, the Fourth Ventricle is situated, which extends from
 the Eminences  called  Testes to the posterior inferior
 Notch of the Cerebellum.
   A little lower than the Testes, the Ventricle becomes
 wider, and  forms an angle behind, from which again  it
 contracts, and  becoming narrower  and pointed below
 like a  writing pen, is called  Calamus Scriptorious.
   Over the  under  end of the  Aquaeductus Sylvii, and
 upper part of the fourth Ventricle, there is a thin Me-
 dullary Lamina, called  Valvula, but properly  Velum
 Vieussenii.
   At the  sides of the  Velum Vieussenii there are two
 Medullary tracts, called Processus ad Testes, or Column*
 Valvula Vieussenii.
   The under end of the  Ventricle  is  found to be shut
 up by  its Choroid Plexus, which prevents any commu-
 nication between this cavity and that of the Spine.

       UNDER SURFACE OF THE BRAIN.

   Near the  middle of  the Base of the Brain, and be-
 tween its Lateral Lobes  there are two  small, round,
 white  bodies, termed Eminentia Mammitares,  or Cor-
pora Albicantia,  Medullary  without, Cineritious within,
 mistaken by some Authors for Glands.
   In the Corpora Albicantia, \arious Medullary  Strata
 terminate, which come from different parts of the Brain.
   Immediately before  the  Corpora  Albicantia.  two
 large white  cords are observed, called Crura, or Pedun-
 euli Cerebri, ov Crura Anteriora Medulla Oblongata, which
 arise from the Medullary Substance of the Brain, and
gradually approach  each other in their course, till they
unite with the Tuber Annulare.
  Their Surface  is flat  and  composed  of  distinct Me-
dullary Fibres;  internally they are composed of a Mix-
ture  of Cineritious and  Medullary Matter the former
at  which being of a  darker colour at one particular part 
25
tk-an in any other of the Brain, has been termed Loius
Niger Crurum Cerebri.
  Between the Crura Cerebri  and Corpora Albicantia,
there is a Cineritious Substance, called  Pons Tarini,
which joins these two bodies of the opposite sides to-
gether, and assists in forming  the bottom of the third
Ventricle.
  From the Medullary part  of the Cerebellum, which
forms the Trunk of the  Arbor Vitae two white cords a-
rise, under the name of  Crura  Cerebelli or Crura Postr-
riota, or Pedunculi Cerebelli- which unite with the Crura
Cerebri, to compose  the  Tu,';er Annulare, or Pons Varo-
lii, so named from forming a  Ring or Bridge over the
Crura.   This ring is intimately incorporated with, and
formed by these Crura.
  The Tuber Annulare is situated over the back-part of
the body of the Sphenoid and Cuneiform Process of the
Occipital Bone.  Many  transverse streaks run on its
Surface, and it is divided into two lateral parts by a
longitudinal depression,  occasioned by the situation of
the Vertebral Artery.
   At the. fore and back parts of the Tuber, are the Fo-
ramina Caca Anterius et  Posterius, the former placed 'be-
tween the third, and  the latter between the sixth Pair
of Nerves : These two Foramina penetrate only a  little
way at the edges of  the Tuber, and receive a Plexus
of Vessels.
  In the Substance of the Tuber, there is much Corti-
cal Matter, which is  formed into Stria, running in dif-
ferent directions.
  Continued from the Tuber, there is alarge Substance
in form of an inverted Cone, which extends to the Fo-
ramen Magnum of the Occipital Bone, under the name
of Medulla Oblongata.
  Upon the Surface  of the Medulla  Oblongata, two
small Eminences appear,  which run longitudinally and
contiguous to each other, and from their shape have the
name of Corpora PyramidaIia, or Eminent* Pyramidales.
  Between the Corpora Pyramidalia, there  is  a deep
Fissure, into which  the  Pia   Mater penetrates, and
where Blood vessels pass into the  interior part of the
Medulla.
   At the outside of  the former Eminences, are two  o-
                       B  3 
                        26
thers, somewhat of the form of Olives, from which they
are termed Corpora Olivaria, or Eminent* Olivares.
  More externally than  these, are two other Eminen-
ces, less evident than the former, which have been des-
cribed by some Authors by the name of Corpora Pyra-
midalia Lateralia.
  The Medulla Oblongata is divided into two lateral
portions, by an anterior  and posterior Fissure, and the
two portions are formed of Medullary Matter without
and a large proportion of Cineritious Matter internally,
and joined together by Medullary F'ibres.
  The Brain is the Grand and Primary Organ of Sense,
with which the mind is supposed to be most immedi-
ately and  intimately connected, and from which the
Nervous Influence is found, by experiment, to be com-
municated to all the other parts of the Body.

                 Origin of the Nerves-
  The Nerves arise from the Medullary  parts of the
Brain, some in solid Cords, others in separate Threads
which afterwards unite  into Cords ;  and have  their
name in numerical succession, according  to their situ-
ations, beginning  anteriorly.
  The First, or Olfactory Pair of Nerves, arise from the
back-part of the  posterior lobes of the Brain, and run
towards the Crista Galli of the Ethmoid Bone, over
which each  forms a brownish  coloured Bulb,  from
whence numerous small Nerves are sent off.
  The Second Pair, or Optic Nerves, are  the continua-
tions of the  Thalami Optici.  They  are united imme-
diately before the Infundibulum, and form an intimate
intermixture  of  parts,  and again separate previous to
their  passing into the Orbits.
  The Third Pair arise  by numerous' Threads,  which
are soon collected into Trunks.
  The Fourth Pair, which are the smallest Nerves of
the Body, arise behind the Testes, and have a long and
winding course.
  The Fifth Pair, which are the largest Nerves in the
Brain, have each an anterior small, and a pos.<•: ior
large Fasciculus,  which arises from the side or the Tu-
ber Annulare.
  The Sixth Pair, arise  from the beginning of the M<- 
                        27
dulla Oblongata,  where it joins the Tuber Annulare.
Eaeh of the Nerves of this Pair has a small Thread at
its inner part.
  The  Seventh Pair arise from the beginning of the la-
teral parts of the Medullary Oblongata, and are divided
on each side into a Portio Mollis, and Portio Dura.
  The  Eighth Pair arise by small  Fasciculi from the
Corpora Olivaria.
  The  Ninth Pair of Nerves also arise by small Fasci-
culi, a  little below the former, from the Corpora Pyra-
midalia.
  The  origin of the Nerves will be described at great-
er length in a subsequent part of the Volume.
                OF THE  EYE.


   The Eyes, which constitute the Organ of Vision, are
 situated in the Cavities of the Orbits, and are surround-
 ed by several parts, some of which protect them from
 injury, and others assist in the performance of their va-
 rious motions.
   The Orbits are formed of two  Cones, situated in the
 fore-pat of the  Cranium, with  their Apices  behind
 their Axes in an horizontal situation, and  their Bases
 turned obliquely outwards.
  Each of the Orbits is formed of different Processes
 of the following Bones, viz.
  The upper part of each Orbit, by the Orbitar Plate
of the  Frontal  Bone ;—the inferior, by  the  Orbitar
 Plates of the superior Maxillary  and Malar Bones ;—
the internal, chiefly by the- Orbitar part of the Os Un-
guis  and Pais Piana of the Ethmoid Bone ;—the exter-
nal, by the Orbitar Plates of the Sphenoid and Malar
Bones ;—the posterior, by  the  Sphenoid and  Palate
Bones ;—and the anterior edge of the Orbit,  by the
 1 lontal, superior Maxillary, and Malar Bones.
  The cavities of the Orbits are lined with Productions
                     B 4 
28
of the Dura Mater, which  pass  out at the Foramina
Optica and Lacera, and,  at the  anterior edges of the
Orbits, join the Periosteum of the Face,  where they
supply the place of Ligaments of the Palpebrac.
                     Supercilia.
  The Supercilia, or Eye-Brows,  which are peculiar t»
the Human species, are the arches of Ha<r situated up-
on the Superciliary Ridges of the Frontal Bone.  The
Hairs are -placed  obliquely, with their roots  towards
the Nose, and the Arches elevated a little above the
rest of the Forehead, by a considerable quantity of Cel-
lular Substance lying under the Skin.
  They are moved in different directions by the action
of the Frontal Corrugator, and Orbicularis Palpebrarum
Muscles.
  They are intended partly for ornament, and partly as
shades over the eyes, thereby preventing them from
being injured by extraneous Matter, or by too great a
quantity of light.  They also assist in expressing the
passions of the Mind.
                     Palpebrtc.
  The Palpebra, or Eye-lids, are chiefly composed of a
doubling of the Skin, inclosing part of the  Orbicularis
Palpebrarum Muscle, and the Cartilages called Tarsi,
and forming angles at their outer and inner extremities,
termed Canthi, or Corners of the  Eye.
  The Upper Eye-lid is one which moves principally in
closing or opening the Eye, the under moving only when
the Eye-lids are shut with uncommon  force.
  The motions of the Eye-lids  are performed bv the
action of the Orbicularis andLevator Palpebrarum Mus-
cles.
  The Eye-lids serve  as curtains or Veils, to defend
the Eyes  during sleep : They likewise  prevent them
from being injured  by extraneous objects, or by too-
much light. By their frequent motion  thev increav-t|,e
secretion of the Tears, apply them proper! v to the Sur-
face of the Eye, and conduct what remains", after wash-
ing the Eye, to the Puncta Larcymaiia.
                       Tarsus.
  This is a thin Cartilaginous Arch, situated in the  edge 
                          29
 of each Eye-lid, that in the upper one being considera-
 bly broader than the one  below, and  each broader at
 its middle than towards its extremities.
    Their edges  are  so placed, that when the Eye-lids
 are shut, a  groove is left next the  Eye  by which the
 Tears are conveyed  towards- the  Nose —They termin-
 ate at a little distance from the inner angle of the Eye.
    They serve to keep the Eye-lids extended, allow them
 to be  accurately  applied to each  other, and prevent
'them from being collected into folds.
    Glandula Sebacea,  Ciliares, or Meibomian*,—the last
 term obtained from their being described by  Meibomius,
 —are placed between the Tarsus and lining of the Eye-
 lids, and  are formed of a series'of white lines or Folli-
 cles, running in  serpentine  directions, which  when
 viewed through a magnifier, appear like rows of Pearls,
 from which an Oily or Sebaceous Matter,  resembling
 little worms, may  be readily squeezed out through the
 Foramina or Puncta Cilaria, placed  upon the edges of
 the l.ye-lids.
    The Matter of the Sebaceous Glands facilitates the
 motion of the  Eye-lids, and  prevents their accretion
 during sleep.
                        Cilia.
   The Cilia, or Eye-lashes,  are stiff Hairs placed in the
 edges of the Eye-lids.  Those of the  upper Eye-lid are
 bent upwards, and are considerably  longer than those
 of the  under Eye-lid,  which are bent in the opposite
 direction.  In both Eye-lids, they are a wanting near the
 inner Angle.
   The Cilia prevent dust, insects,  fcc. from getting in-
 to the Eye,  and assist hi moderating the quantity of
 light sent into it, and add to the beauty of the Face.
                Glandula Lacrymahs.
  The  Glandula  Lacry malts,  called, till of late years,
 the Glandula Inntrminata Galeni, is situated upon the
 upper and outer part of the Eye, in a hollow behind the
outer end of the Superciliary Ridge of the Frontal Bone.
 It  is a Gland of the Conglomerate  kind, of a yellowish
colour, of an oblong form, and a little flatted, with one
end pointing' to the .Nos*, the otiiei- to the outer angle of
the i.ye. 
30
  Besides this, their is a chain of Smaller Glands, lying
between  the  principal Gland and upper Eye-lid, and
connecting them together.
  In the  direction of the Smaller Glands, there are se-
veral Excretory Ducts,—described  by Db.  Monro,
1758,—which run nearly parallel to, but do not commu-
nicate with each other.
  The Excretory Ducts, on account of their smallness,
are not often seen, and are difficult of injection.  They
terminate on the inner side of the upper Eye-lid, near  •
the outer angle of the Eye, and upper edge of the Tar-
sus.
  The use of this Gland is to  secrete  the Tears,  which.
are spread over the Surface  of  the  Eye  by their own
weiglit, and by the motion of the Eye-lids, for the pur-
 fiose of preserving the delicacy of the Eye, and particu-
 arly the transparency of the  Cornea.
                Puncta Lacrymalia.
  The Puncta Lacrymalia are two small Orifices placed
near the inner angle of the Eye, one in the upper, the
other in  the under Eye-lid, at the extremity of the Tar-
sus,  and opposite to each other.
   Each  Punctum is seated obliquely upon a small emi-
nence, and is surrounded with a Cartilaginous  Circle,
 which keeps it constantly open.
   The Puncta Lacrymalia  are the Orifices of two small
 canals which run in the directien of the edges of the eye-
 lids towards the side of the Nose, where they approach
 each other,  and terminate together in the Lacrymal
 Sac.
   The Tears  which remain after moistening the Eye
 are absorbed  by  the Puncta,  after the manner of Ca-
 pillary attraction, and are conveyed through their Ducts
 into the  Lacrymal Sac by the impulse of the Eye-lids.
                Caruncula  Lacrymalis.
    The Caruncula Lacrymalis is a small Gland of a red-
 dish colour of the  Conglomerate kind, situated between
 the inner angle of the eye-lids and Ball of the eye, which
 supplies Sebaceous Matter  to this part oi the eye-lids-
 and serves in  particular to separate  the Puncta Lacrv-
 mulia,  and to direct the Teurs to them while the eve,
 lids are shut. 
                          31
     Minute Hairs are found upon the Surface of this Bo-
  dy, serving to entangle objects Which get into the eye.
                   Valvula Semilunaris.
    The Valvula Semilunaris is a small  doubling of the
  Tunica Conjunctiva,  which  lies  between  the  Carun-
  cula Lacrymalis and Ball of the eye.
    It is larg r in the Ape and other Quadrupeds than in
  the Human species, and still larger in Birds,  in which,
  as well as in Quadrupeds, it is called Membrana Nicti-
  tans.
    It  is in form of a Crescent, the horns of which are
  turned towards the Puncta Lacrymalia,  and assists the
  Caruncula in  conducting the Tears to the Puncta.
               THE BALL OF  THE  EYE.
    The Ball,  Globe, or Bulb of the eye, is of a spherical
  form to collect the rays of light into  a proper Focus, and
  is surrounded behind by a quantity of soft Fat, to allow
  the eye and its Muscles to move with facility.
    The  Ball of the eye is composed  of Coats, Humours,
  Vessels, and Nerves, to be next described.
                       COATS.
                    Tunika Adnata.
   The Tunica Adnata, or Conjunctiva, named from its
 connecting the eye to the Orbit, is a reflection of the
 Skin continued from the  eye-lids over the whole  fore-
 part of the Ball of the eye.
   It adheres slightly, by means of Cellular Substance,
 to the White of the eye, but so  firmly to the Cornea, as
 to be separated from it with difficulty.
   It is  so remarkably thin, that the colour of the sub-
jacent parts shine readily through it.
  Between this Coat and the white part of the eye, there
is a quantity of loose Celhilar Substance, which is very
Vascular, and is the common seat of Ophthalmia.
  The  Tunica  Adnata supports the  Ball of the eye,
prevents extraneous  bodies from getting to the back-
part of it, and  forms a smooth covering to lessen the
friction between the eye and eye-lids.
                       Cornea.
  The Cornea,  so called from its resemblance to Horn, 
                         32
  t
is termed by many Authors Cornea LuciJa, to distin-
guish it from the Sclerotica, named Cornea Opaca.
  It forms the anterior Pellucid Covering of the eye, ia
more convex than the rest of the Ball, and is  joined to
the  Tunica Sclerotica,  like  the Segment of a small
Sphere to that of a larger one.  The convexity, however,
■varies in different persons, so as to form a short or long
sighted Eye, according as the Cornea is more or less
prominent.
  la a recent subject, it is hard  dense,  and transpa-
rent ; but after maceration in water, it becomes soft and
opaque,  and may  be readily  separated,  especially in
young Animals into a different Lamellae, the anterior
of which is the continuation of the Tunica Adnata.
  By a slight degree of putrefaction, it  may  also be
separated from the Tuiica  Sclerotica.
  In.trie Whale, the edge of the Cornea is received in-
cr a distinct Groove formed by the Sclerotica.
  In a sound state, it has no Vessels which  carry red
Blood, though such are frequently seen on it when the   |
Eye is inflamed.
   Its nerves are too small to be traced ; yet it posses-
ses exquisite sensibility.
   It collects the ray s of light, and transmits them to the
 Lye, protects  the tender parts within it, and contains
 tb,e Aqueous Humour.                                 j
                        Iris.
   The Iris, which is nam< d from being in some persons
 fif differ* nt  colours, is the only Coat which possesses
 not on.' It was considered  as  a continuation of the
 Civwoid Coat, until described by Zinn, who  shews that
 ii  is <.nb  connected to this Coat by. the medium of the
 Cifi: i \  Circle.                                       j
    It is placed at a little distance from the Cornea, be-
  eins a small way behind the junction oi that  Coat with
 'lie''9.'. lerptica, and running across, it forms a Septum,
  a lit • ic  convex anteriorly  and perforated in  the middle
  b\ a Hole, called the Pupil,  or sight of the  Eye.
    The  trim Pvpil is applied, because it represents ob-  ',
  jects no larger than a Pupilla or Puppet.                ,
    \n the  Fuitps,  the Pupil is covered with a Vascular  I
  Membrane, termed Membrana Pupiilaris, winch gene?  ; 
33
rally disappears between the seventh  and ninth month
of gestation.
   Upon  the  back-part of tha Iris, there is a dark-co-
loured Pigment, considered by the Ancients as a poste-
rior Layer of the Iris, called by them  Uvea,  fiom its
resemblance  in colour to the  Grape.
   When the  Paint is  washed off, the Iris exhibits two
sets of Fibres,—concerning which Authors have enter-
tained various opinions,—one in the form of  Radii, the
different colours of which give the diversity of colour
to the Eye ;  the other circular, and  surrounding the
inner edge of the Iris, and considered by Dr. Moneo
as the Sphincter Muscle of the Pupil.
   The Iris has also many Blood-vessels, which can be
readily injected ; and has a greater  portion of Nerves-
than almost any other part of the Body.
   It floats in  the  Aqueous Humour,  and is of such a
nature, that  upon exposure to a strong light,  or when
the Eye  looks upon a near object,  the diameter of the
Pupil is  diminished j  and vice versa.
   The different motions of the Iris are  supposed to be
excited by the  sensibility of the  Retina, and the quan-
tity of light falling upon that Nerve.
   The Iris serves to regulate the quantity of light sent
to the bottom of the Eye.
                  Tunica Sclerotica.

   The Tunica Sclerotica, which is named from its hard-
ness, is the largest and strongest Coat of the Eye, cov-
ering the whole Ball,  excepting the parts occupied by
the entrance of the  Optic Nerve behind, and by the
Cornea before.
   It is so firmly fixed to the  edge of  the Cornea, as to
have been  considered by many Anatomists as a  con.
tinuation of the same substance ; but it differs from the
Cornea in  the following particulars ; it is of a pure
white colour, is formed of Fibres running in every di-
rection, and closely interwoven with each other, is not
divisible into Layers, and may be separated from it by
art,  as has been already mentioned.
   It is thickest posteriorly,  and receives a little  tinge
on the inner Surface, from the Choroid Coat, w\th which
It, is in contact. 
34
   It gives form and strength  to the Eye, and supports
the tender parts within it.
   The Tendons of the four Recti Muscles of the  Eye
are fixed to the fore-part of the Tunica Sclerotica ; and
these, or the Cellular Vaginx covering them, have been
supposed to give an additional whiteness to the eye ; and
the part giving this whiteness has been termed Tunica
Albuginea :—But the Sclerotic Coat is every where of a
pure white, and can receive little additional brightness
from any such covering.
                  Tunica Choroides.
  This Coat derives its name from the Vessels with
which it abounds, forming  a  Chorus,- or from its sup-
posed resemblance to the Membrane called Chorion,
which surrounds the Foetus in Utero.
  The Choroides lies under the Scleroticd, and  is con-
nected to it by the Trunks of Vessels and Nerves which
pass from the one Coat to the other, and also  by a ten-
der Cellular Substance, of a brown colour, with which
the inner Surface of the Sclerotica is tinged.
  It begins at the entrance of the Optic Nerve into the
eye,  runs between the Sclerotica and Retina, nearly to
the Crystaline Lens, where it is more firmly connected
to the Sclerotic Coat than it is elsewhere, by  means of
the Ciliary Circle.
  The Ciliary Circle, or Ciliary Ligament, as it is called,
is composed of a quantity of condensed shining Cellular
Substance, which forms a white Ring connecting the
fore-part of the Choroides, and the root or outer Mar-
gin of the Lis, to the Sclerotica.
  The Choroid Coat is much  thinner and more tender
than the Sclerotic, and is one of the most  Vascular
parts of the Body, seeming at first sight to be entirely
composed of Vessels.—The greater number of those on
the outside run in  whirls:-while those  on the inside,
running nearly parallel to each other, gave rise to the
supposed existence of the Membrana  Ruyschiana.
  It is also furnished with numerous Nerves, which are
united with its Vessels by a fine Cellular Texture.
  In the human eye, the Choroides is of a dusky brown
colour,  both externally and internally ;  but the colour
varies considerably  in the eyes of different animals- 
35
   The inner Surface of this Coat, which is Villous, was
 described by Ruysch as  a Distinct Lamina, and has
 been termed by many Anatomists Tunica Ruyschiana ;
 Halle a however,  and  Ziy.v, and  many others  who
 followed them,  have demonstrated this Coat to consist
 of only one Lamina ; though in Sheep, and in some other
 animals, it appears to be double.
   Upon the inner side of the Choroides, there is a dark
 coloured  Mucus, called Pigmentum Nigrum —supposed
 to be produced from the vessels of this Coat,—which" is
 blackest and thickest at the fore-part of the eye, where
 it adheres so tenaciously as to be removed with  diffi-
 culty ; but behind it is thinner,  more fluid, and more
 easily removed : becoming gradually less  evident,  and
 almost disappearing round the Optic Nerve.
   In advanced age,  the Pigmentum  Nigrum becomes
 more diluted, and of a lighter colour;  so tiiatthe Ves-
 sels of the Choroid coat may be seen shining through the
 Vitreous Humour.
   Though Hali.er denies that  the Membrana Ruys-
 chiana can ever  be separated, in the  Human Eye, from
 the  Choroides —he retains the  name, to denote the
 black  Surface of this Cout.
   In grameniverous animals, in  fishes, and in  those
 animals which go  in quest of prey  in the night,  the
 Paint is of a light and shining colour in the bottom of
 the  eye, and is  called Tapetum.—In an entirely white
 Rabbit, the Paint is a wanting, and  the eye has a red
 colour from the  Vessels of the Choroid coat;  but  the
 redness disappears when the animal is dead.
   At the fore-part of the Choroid coat, and opposite to
 the Ciliary circle, there is a black radiated Ring, cal-
 led Corpus Ci U art, which is about the sixth part of an
 inch in breadth  towards  the Temple, but somewhat
 narrower towards the Nose.
  in the posterior portion  of the Corpus ciliare, there
 are numerous pale radiated Cailiary Stria,  but so  co-
vered with the Pigmentum Nigrum, as not to be distinct-
ly  seen till the Paint is removed.
  Near the connection  of the Corpus Ciliare with the
r</it  of the Iris, these Striae become gradually broader
and more elevated, and form about twenty white  ttica 
                         36

 or Folds, termcdProccssus Ciliares, the intervals of which
 are also covered with Pigmentum  Nigrum.
   The Processus Ciliares, which obtain  their name from
 their resemblance to the cilia of the eye-lids, are com-
 monly formed each of two or more Striae, are not all of
 an equal size, and many of them forked at their extre-
 mities.
   The Corpus Ciliare, formed of the ciliarv Striae and
 ciliary Processes, has no  appearance  of  Muscularity,
 though the contrary has been supposed, by  some Au-
 thors.  A fine injection shews it to be chiefly formed of
 a continuation of the Blood-vessels of the Choroid coat,
 the branches of which divide into such  minute parts, as
 to give the whole a Villous appearance.
   The corpus ciliare is glued to the Retina, at the fore-
 part of the Vitreous Humour,and a little behind the edge
 ot the crystaline Lens ; but the ciliary processes float in
 the  Aqueous Humour  in the posterior chamber of the
 eye at the inner side of the root of the Iris, and  may be
 readily turned back behind the edge of the Lens,  to
 which they are contiguous, but do not adhere.
   The Choroid coat, with its dark Paint, serves to suf-
 tocate the rays of light which pass  through the  Retina,
 and thereby to allow a distinct image to be formed up.
 on the bottom of the eye, and to prevent the rays from
 being reflected so as to form  a second  image.
   In these animals in which this coat or its paint is of
 a bright colour,  it acts as a mirror to reflect light, and
 make the impression stronger.

              Optic Nerve and Retina.

  The Optic Nerve,  in its passage through the Orbit,
 is  covered  by a continuation of the Membranes which
 surround the Brain.
   At the Foramen Optiaum, the Dura Mater is divided
 intorwo Lamina, one of which  assists in forming the
 Periosteum of the Orbit; the other, which is again  djw
 vided into two Laminae, furnishes a sheath to the Nerve,
 and accompanies it to the Tunica Sclerotica, to which  i
it  is so firmly connected by cellular Substance, as to.
nave induced some Authors to describe the Sclerotica #
 as  a continuation of the Dura Mater.
i 
                         37
   The Body of the Nerve is still more closely invested
 by the Pia Mater, which also forms sheaths rour*. the
 Nervous Fasciculi, and accompanies the Nerve into the
 eye.
   At  the back-part of the  Ball of the eye, and a little
 removed from the  Axis,  towards the  nose, tin Fasci-
 culi of the Optic Nerve pass through a Cribriform part
 ol the Sclerotic coat.
   The Nerve is contracted at its entrance through the
 Sclerotic coat, but immediately after its ingress, it ex-
 pands to form the Retina,—so called from  its supposed
 Reticular appearance.
   In the middle of the entrance of the Optic Nerve, the
 Artery  is seen diuding into branches, which are dis-
 persed upon the inner Surface of the Retina.
   The Keiiua advances between the Choroid coat and
 Capsule of the Vitreous  Humour,  to  the  fore-part of
 the eye, and terminates or disappears upon the anterior
 part of the edge, or  greatest diameter of the Capsule
 of the Crystalline Lens.
   The Retina is contiguous to  the Choroid coat and Cap-
 sule of  the  Vitreous Humour, but does not actnere to
 either, by Blood-vessels or otherwise, till it reaches the
 Corpus  Ciliare.
   Under the Corpus Ciliare,  the Retina is so covered
 externally, with the Pigmentum Nigrum, and aciheies
 internally  so closely totiie Capsule of the Vitreous Hu-
 mour, as to be prevented from being seen till the black
 Paint  be washed off, or till all the coats  be removed
 posteriorly, and the eye viewed through the medium of
 the Vitreous Humour.
   'The Retina is composed of a tender aud Pulpy like
 Substance, is semi-transparent, and of a light-grey co-
 lour, resembling that of giound glass.
   From the entrance of  the Optic Nerve,  to the edge
 of the Corpus Ciliare, the  Ketina is of an equal and
 uniform  Substance, and is so  easily torn ami separated
 from the edge ot that body, as to be described by many
.Authors as terminating there.          <
   Under the Str.x and Processes of the Corpus Ciliare,
 flic  Retina is thinner than  in the  posterior pan o! the
 eve, and is  so impres*id  by these budic*, as also tn
 lui\e the appearance of  Striae, which terminate in nu*
     VOL. 11.             V 
                        38
merous minute Fibres, like Nerves in other parts of the
Bodj.
  The Retina  is the seat of Vision,  and therefore the
primary part of the eye, to  which  all the other parts
within the Orbit are subservient.
                    Humours.
                  Aqueous Humour.
  The Aqueous Humour is lodged in the space between
the Cornea and Crystalline Lens.
  This space is divided into two Cavities called Cham-
bers, the anterior of which is situated between the Cor-
nea and Iris, and is the larger ot the two.
  The posterior is  placed between the Iris and Crystal-   |
line Lens, and is so much smaller than the former, that
its existence has been denied by some authors, though
it is a distinct cavity, demonstrable, not only in the
Adult, where  the  Pupil is open, but in the Foetus be-
fore the Pupil is formed.
  The Aqueous Humour is clear as  the purest Water,
but is somewhat heavier, possesses a small  degree of
viscidity, contains  a little Salt, and is about five grains
in weight
  In the Foetus, and for the  first month after birth, it
is reddish and turbid.
   When evacuated, it is quickly renewed ,- for within
forty-eight hours after it has  been let out by a puncture
tlie Cornea is observed to be again perfectly distended,  i
   It is supposed to be  secreted from the neighbouring
Arteries, particularly from those on  the fore-part of the
Ins and Ciliary Processes.
  It serves  to keep the Cornea distended, and by its  i
roundish form and pellucidity, it collects and transmits
tne ravs ot light to the uinei  parts 01 toe eye.  It like-
wise guards the Ins and Lens, and  admits of tlie mo-  \
liens of the former.
                    Crystalline Lens.
  The Crystalline  Lens, wlncu has its  name from its
resemblance to Crystal, and from us  Lenticular form,—
though a solid body, which may be moulded into various  1
shapes, has always been classed among the Humours of
tlie eye               * .
   It ib situated behind the Aqueous Humour, opposite 
                         39
to the Pupil, and the whole of its posterior parts is re-
ceived into  a depression on the fore-part of the Vitre-
ous Humour.
   Like  a common Lens, or magnifying Glass, it  has
two convex Surfaces, the anterior of which is in general
less  convex than the posterior, the two being formed
of segments of spheres of an unequal size.
   The anterior Surface, according to the experiments
of Petit, forms the segment of a sphere, the diameter
of which is between seven or eight lines, or twelfths of
in inch ; while the posterior Surface is only equal to
tlie segment of a sphere of about five lines in diameter.
   It has been observed  by Zinn,—that the figure of
the  Lens  varies  at different periods,  being in  the
Foetus almost of a spherical form, but becoming gradu-
ally Hatter on the anterior and posterior Surfaces, till
about the age of thirty, after which its form does not
appear to vary.
   As the figure,  so also the colour and consistency are
found to change at different limes of life—In the Foetus,
not only the Capsule, but the  Lens also is of a reddish
colour; but immediately after birth, they become per-
fectly transparent.—In a person considerably advanced
in years, the Lens is observed to acquire a certain de-
gree of yellowness,  which appears hist in the centre,
and afterwards extends gradually to the  circumference,
and  in extreme old age, this yellow  tinge becomes so
deep as to resemble Amber.
   An Aqueous Fluid is described as being situated be-
tween the  Crystalline Lamellae,  which is supposed to
decrease in  quantity, and become yellowish, the Lens
at the same time increasing in solidity as the person ad-
vances in life.  This difference however, of convexity,
colour,  and consistence, according to the difference of
age, is  not uniformly met with.
   The Lens becomes opaque soon after death, and ac-
quires an  additional opacity when put into spirit of
wine.
   It is composed of concentric Lamellae, laid over each
other like the coats of an  Onion.  These Lamellae, are
connected by  a fine Cellular  Substance, and are more
closely  compacted the nearer they are to the centre.
   This lamellated structure may be readily observed 
40
in the eve of an Ox, or any other large animal, but is
most evident  when the Lens l.as been macerated in
Water or Vinegar.
  When the maceration is continued for sometime, the ■
Luiullsc put on a radiated appearance, tne Radii run-
ning in a vertical manner, or issuing from the cent: e to
t'e circumference,  dividing the Surface into Isosculaf
Trim rles
  The  Lamellae were discovered by Levwf'.hoick,
to be of a Fibrous structure.   Bv a late writer, these
Fibres have been ror.s were das Muscular,—but this O-
pu-.in'i  of  the Muscularity of the Lens, seems to have
gained very  few proselytes.
  The substance of the Lens somewhat resembles half-
melted gum, is very soft and  tender on  the or.tside,
but becomes gradually firmer and tougher towards the
centre, where it forms  a Nucieus.
  The Lens is surioundcd by a  very pollucid proper
Capsule, called Tunica Aranea or Crystallina, which is*
much thicker and more  elastic than the Capsule of the
Vit eons Humour,  but adheres so  slightly,  and is so
easily lacerated, that after a small puncture is made in
it, the  Lens si art out, upon applying gentle pressure to-
the Capsule.
  The posterior part of the Capsule is much thinner,
softer, and  weaker than the  anterior ; but is quite a
jjstinct Membrane from  the  Tunica  Vitreje ;  yet  so
family  connected to it by Cellular Substann , that it is
difficult to separate them without  lacerating both the
Vitreous coat and its Humour
  Some Autlm.s describe an Aqueous Humour as seated
between the Lens and its Capsule;  while others, of ho
small respectability, deny the existence of this Humour
as well as of that which is said to be situated between
the Lamellatof the Lens.
  The Vessels of the Lens arc not to be seen in the eye
»f an Adult; but in that of a Fu-tus, Pa in found ves-
sels passing  from the Corpus Ciliaie, over the fore-part
of the  Capsule of the Lens.
  Winsi.ow afterwards observed, that  in the Foetus*
and in new-born childien, a fine injection succeeded so
well as to discover the  Vessels of the Mtmbrana Cr; s-
tttUiua and Vitiea j—and in a Foetus of about six months* 
                          41
 the injected liquor seemed to him to have penetrated/a
 part of the Crystalline and Vitreous Humours.
   A lb in is derives these Vessels from a double source.
 In the eye of a Whale, he demonstrated Vessels pas-
 sing from the Ciliary Processes to the Substance of the
 Lens ;—and, at a later period,  he injected in  the hu-
 man eye, a  small branch  arising from the Central Ar-
 tery of theRetina,  which proce ded in a straight direction
 through the  Vitreous Humour, and divided in the pos-
 terior part of the  Capsule into numerous branches,
 many twigs of which plunged into the Substance of the
 Lens.
   This artery and its branches have been frequently and
 successfully injected by succeeding Anatomists.
                  Vitreous Humour.
   The Vitreous Humour, so called from its resemblance
 to melted Glass, is situated in the back-part of the Ca-
 vity of the eye, which it occupies from the insertion of
 the  Optic Nerve to the Surface of the Crystalline Lens.
   It is round at the back-part and sides, where it is
 covered by the Retina, but is concave before, where it
 forms a  bed  for the Crystalline Lens.
   It is by much the largest of the three Humours, oc-
 cupying upwards of nine-tenths of the whole eye, and
 has  a Gelatinous appearance,—or  is somewhat like the
 glare of an Egg.
   In an Adult  it  is always very transparent," and in an
 Old  Person it does not, like the  Lens, degenerate into
 a yellow, or any other colour.
   In the  Foetus, like the  Aqueous Humour, it is of a
 reddish colour.
   The liquor with  which  the Vitreous Humour is fil-
 led,  is similar to the Aqueous,—very  fluid, transpires
 readily through the Capsule, though that coat be entire,
 and, like  the Aqueous Humour,  is somewhat thicker,
 heavier,  and  more viscid than Water.
  When this Humour is evacuated by puncture, in the
living Body, it is  very seldom,  though sometimes re-
newed.
 Upon the surface  of this Humour there is a coat, term-
ed Vitrea, as  transparent as the  Humour itself, and
so thin and Cobwcb-hke, as to have the name of Arena.
                       c  2 
42
   The Tunica Vitrea is remarkably smooth on its outer
 Surface ; but within, it sends Processes into the body
 of the Humour.
   Some  Authors, and among these Wisst.ow, have
 described this coat as consisting of  two Laminae,  but
 Sabatier, and  other late  writers,  seem  sufficiently
 satisfied that it is a single Layer ; and even  this single
 Layer cannot be raised but with difficulty, though it is
 demonstrable by  making a  puncture to allow the Hu-
 mour to escape, and by afterwards distending the part
 with air.
   The structure of the humour consists  in a set of de-
 licate Cells, which contain the liquor within them,  as
 my be seen by the assistance of Acids,  or  by  boiling
 Water, or by Congelation.
   The Cells of the  Humour communicate freely with
 each other, as appears from the liquor oozing  out  by
 the smallest puncture made  in the general Capsule.
   Under the Corpus Ciliare, the Capsule of  the Vitre-
 ous Humour sends off' an  external Lamina,  which ac-
 companies the Retina, and is inserted with it into the
 fore-part of the Capsule of the Lens, a little before  its
 anterior edge.  It is termed Membranula Corona Cilia-
 ris, or Zomula Ciliaris, from  its Striated appearance
 and circular .form, and assists in fixing the Lens to the
 Vitreous Humour.
   After  sending  off the Ciliary Zone, the coat of the
 Vitreous Humour goes behind the Capsule of the Lens,
 to which it firmly adheres.
   Between  the Ciliary Zone and part where the Cap-
 sule of the  Vitreous  Humour adheres  to that of the
 Lens,—which  is  at the same distance behind the edge
 of the Lens,  with the distance of the insertion of tfee-
 Ciliary Zone before  it,— a  Passage   is formed,  named
 Canalis Petitianus, after Petit, who discovered \\.
   The  Membranes forming  this Passage are pervaded
by transverse Fibres,  in such a manner,  that when  air
is introduced, it goes freely round the edge of the Lens;
but the Passage has a Cellular appearance, being con-
tracted and dilated alternately.
   The Canai of Petit is  nearly of the  same breadth
with tue Corpus Ciliare, is always empty,  and has no 
43
communication with  the Capsules  of the Vitreous or
Crystalline Humours.
   No vessels are to be seen in the Vitreous Humour of
an Adult, but in the eye of a Foetus, an artery is obser-
ved to arise from the central one of the Retina,  which
passes through  the  middle- of the Vitreous Humour,
sending twigs to the Cellular Texture of this Humour,
while tlio principal  Trunk is continued to  the Capsule
of the Crystalline  Lens, as has been already observed.
   The Vitreous Humour serves to give shape to the eye,
to keep the coats properly  expanded,  to preserve the
due distance of the Lefts, and direct the rays of light
to the Retina.

       mtsct.es of  the ball or the eye.

   Tlie Ball of the eye is moved by six Muscles, which
are d'n i'i':d,  on account of their  diicction  into four
straight and two-oblique Muscles,  obtaining their respec-
tive names from their size, situation, direction, or use.
   Of the straight Muscles,  one  is  situated above the
eye, another below it,  and  one  on each side.  Of the
oblique, one is placed at the upper  and inner, and the
other at the under and outer part of the eye.
   The Recti Muscles are not straight,  as tlie name im-
ples ; for on  account of the situation of the eye and
shape of the Orbit, the internal,  or that next the Nose,
is the only one which runs in a straight direction.
   Neither are they all equally long,  the  internal being
the short <--st, the cxte;nal the longest, and the other two
nearly of liie sm.c length.
  The four straight Muscles, which bear a strong re-
semblance to each other, arise by a narrow beginning
a little Tendinous and Fleshy,from the edge of the Fora-
men Oj'icum, where they embrace  the Optic Nerve at
its entrance into the  Orbit.
  In their passage forwards, they form Fleshy Bellies,
which send >>ll'b;oad and very thin  'Tendons,  to  be in-
serted into the Sclerotic coat, under the Tunica Aiulata,
about a quarter of an inch behind the cd^c  of the Cor-
nell, and at i ijiial distances from  each other.
   At the place "(their insertion tliey are so intimately
ionntcted with the Sclevctica, that thev  cannot be se-
                        c  3 
                       44
parated from it, or be  brought as  far as the Cornea,
without evident laceration.
  The different Muscles of the Ball of the eye, where
they lie upon the Ball, are covered with a Cellular
Sheath, which afterwards degenerates into that Cellular
Substance which is interposed between the Sclerotica
and Conjunctiva.
                Levator Oculi ;
           Or Rectus Attollens, or Superbus.
  Origin : From the upper part of the Foramen Opti-
cum,  below the Levator Palpebrae Superioris.
  Insertion :  Into the upper and fore-part of the Tuni-
ca Sclerotica.
  Action :  To raise the forepart of the Ball of the eye.
               Depbessor Oculi ;
          Or Rectus Deprimens, or Huviilis.
  Origin : From the inferior part of the Foramen Op-
ticum.
  Insertion: Opposite to the former.
  Action •  To pull the fore-part of the eye downwards.
                Adductor Oculi ;
          Or Rectus Adducens,  or  Bibitorius.
  Origin: From the Foramen  Opticum, between the
Obliquus Superior and Depressor.
  Insertion ■' Opposite to tlie inner angle.
  Action : 'To turn the fore-part of the eye towards the
Nose.
                Abductor Oculi ;
        Or Rectus Abducens, or Indignabundus.
  Origin: From the  Bony Partition between the Fora-
men Opticum and Lacerum.
  Insertion: Into the Ball of the eye, opposite to the
outer an^le.
  Action : To turn the fore-part of the eye towards the
Temple.  When two of the  opposite Recti  Muscles,
or all of them act together, they  draw the eye into the
Orbit.
  When two of the adjacent Recti Muscles  act, they
turn the fore-part of the eye obliquely  in a direction
towards their Origins. 
4.5
               Op-t.iq.vi-s St'PEnion ;
          Or Obliquus- Major, or Trochlearis.
  Origin .*  Like the straight Muscles, from the edge of
the Foramen Opticum, between the Levator and Ad-
ductor  Oculi.  From thence it  runs straight  forward,
sends oft'a long round Tendon, which passes, through a
Cartilaginous Pulley fixed behind the Internal Angular
Process of the Os  Front is : from this  it runs a little
downwards, and returns backwards and outwards, pas-
sing under the Levator Ocwli, to have its
  Insertion:  By a broad thin  'Tendon, into the Tunica
Sclerotica, about half-way between the insertion of the
Levator Oculi and entrance of tlie Optic Nerve.
  Action : 'To roll the Ball of the eye,  by turning the
Pupil downwards and outwards:

              Obliquus Inferior ;
                Or Obliquus Minor.
  Origin : By a narrow beginning,  from the  anterior
rdgeof the Orbitury Process of the Superior Maxillary
Bone,  near the Lacrymal Groove, from which  it pas-,
ses obliquely outw aids,  backwards and upwards, round
the Ball of the eye.
  Insertion:  By a broad thin Tendon, into the Sclerotic
coat,  between the entrance of the Optic. Nerve and in-
sertion of the Abductor Oculi, and opposite to the in-
sertion of the Superior Oblique Muscle.
  Action : To roll the Ball of the eye,  by turning the
P«ipil upwards, and inwards, and with the assistance of
the  Superior Oblique  Muscle, to  pull the eye forwards,
thereby becoming an antagonist  to t,he Recti Muscles.
  The two Oblique Muscles, on account of rolling the
eye, and assistii.g it in  the expression of certain pas-
sions, ha\e been called  Rotatores, or Amatore*.
               VESSELS  or THE EYE.
  The Frontal,  Fascial, and Temporal Arteries,  which
are  branches of the Externa; and  Internal  Carotiiis,
supply  the  Palpebr.-e,  and communicate  with  those
which are dispersed within the Orbit.
  'Some  small  branches of the Internal Maxillary Ar-
tt"r'y pass through the Inferior Orbital1 Fissure,  to  Do'
                       C 4 
                        46
 dispersed chiefly upon the Periosteum of the Orbit and
 Fat of the eye.                     .   ,A  Tm*««,«i
   The Ocular Artery, which is a branch of the Internal
 Carotid, passes through the Foramen Opticum, «" com-
 pany with the Optic Nerve, and supplies the Fat, Mus-
 cles and Ball  of the eye, and also the Lacrymal Gland
 and Tunica Conjunctiva.
   The branches which  belong to the Ball  of the eye,.
 have the name of Ciliares :—They perforate the Sclero.
 tica in different  places, and  are  afterwards dispersed,
 chieflv upon the Choroid coat and Iris.
   One" branch of the  Ocular Artery,  called Centralis
 Retina, perforates the Optic  Nerve, and is disperse*
 upon the  Retina-
   The Veins which correspond with the  Arteries ot the
 eve,  communicate  freely  with each other, and pass
 partly to the External jugularVem, by branches situated
 about the fore-part of the Orbit, and partly  to  the In-
 ternal Jugular Vein  by  the Cavernous Sinus.
               NERVKS  OF  THE EVE.
   Besides the Optic  Nerve, already taken notice of, the
 eye receives the Third and Fourth Pairs, and branches
 from the  first part of the Fifth  Pair, together with the
 Sixth Pair, and  branches from the Seventh.
   The parts about the fore-sidfi, of  the Orbit are sup-
 plied by branches from the Fifth and Seventh Pairs ;—
 the Ball of the eye by  Nerves called  Ciliary, which
 come  from  the third  and Fifth Pairs ;— the fat, Mus-
 cles, Lacrymal Gland, &c. are supplied by the Third,
 Fourth, Fifth, and Sixth Pairs.
   The use of the eye is, to receive and  collect the rays
 of light in such a manner as to form upon the Retina
 the image or  picture of the object which the eye looks
 at; and  the point  where  these  different rays meet is
 called the Focus.
   The object is painted  upon the Retina in an inverted
 manner, the rays from above  falling upon its under, and
 those from below upon its upper part; and it is suppos-
•ed to be by habit, or rather by instinct, that  we judge of
 the real situation of any object.
   That the rays  of  light may terminate distinctly on
 the Retina,, it is necessary that  both the. Cornea and 
                         47
Crystalline Lens should have a certain degree  of con-
vexity.
  If either  the one or the other be too prominent, the
Focus  will be formed before it reach the Retina, as is
the case in short-sighted people, who  rjrquire concave
glasses to enable them to see objects distinctly, at the
proper and ordinary distance.
  If, on the contrary, the Cornea or Lens be too flat,
or the retractive power  of the Humours be in any way
dimished, the  Focus will then be imperfectly formed,
till the object is viewed  at a  greater distance than or-
dinary, as is the case  with persons advanced  in life,
to whom the assistance of convex glasses becomes ne-
cessary.
  How an object, viewed with both eyes, appears sin-
gle, has been ascribed by the generality of Authors to
custom and  habit ; and by others to instinct, which re-
gulates the  uniform  motion  of the eye, and the accu-
rate application of both to one point-
  The eye is enabled to judge of, or accommodate itself
to objects at different  distances,  by  the  action of its
Muscles increasing or  diminishing the length of its
Axis, and by the motions of the  I. is allowing a greater
or smaller quantity of light  to be thrown into the eye.
               OF THE  NOSE.


  The Nose, which is the Organ of Smell, and contri-
butes to the general puipose of Respiiation, is divided
into the External Prominent Part, a..d the Internal Ca-
vity, which is  separated by the  Septum  Narium into
two smaller Cavities ;—or,  it  is divided into hard and
soft pails.
  The External part, or Nose,  properly  so called, is
composed superiorly of Bones, interiorly of Cartilages,
and has a paitial covering from the Muscles, and a ge-
neral one  trimi '.he common Integuments.
  On the c-utaide of th« Nose aie observed,—the Radix, 
48
 or upper part;—the Drrsum, or middle prominence ;—
 the Apex, or point;—the Al*, or lateral moveable parts;
 —and Columna, or under part of the partition next the
 Upper Lip.
   The Osseous part of the Nose is formed by the Ossa
 Nasi, properly so called, the Ossa  Maxillaria  and O*
 Front is, which constitute the upper and fore-part .:
   By the Os  Ethmoides and Ossa Unguis, which form'
 the upper, inner, and lateral parts:
   And by the Ossa Maxillaria Superiaria, Ossa Palati,
 Os  Sphenoides,  Ossa' Spongiosa  Inferior a, and  Vomer,
 which form the under, inner, and  back-part.
   The two Cavities, or Nostrils, terminate anteriorly in
 the Face, and  posteriorly in'the Fauces,  and are much
 enlarged by  the different Sinuses which communicate
 with thein.
   The under and fore-part of the Nose consists of/So*
 Cartilages, of a somewhat regular figure, and of some
 smaller pieces, which  are more irregular, and of an in-
 determinate number.
   Of the five Cartilages, one is situated in the middle,
 and the other four laterally.
   The middle Cartilage is the most considerable, and
 supports the rest: It constitutes the Cartilaginous part
 of the Septum  Narium, and  is joined to the anterior
 edge of the Nasal Lamella of the Ethmoid Bone, to the
 anterior edge of the Vomer, and to the fore-part of the
 Spinous  Process of the Superior Maxillarv Bones.
   Of the lateral Cartilages, two are  placed  anteriorly
 forming  by their curved union the  Tip of the  Nose'
 and  two posteriorly, which form the  A\x Nasi.
   Between the anterior and posterior Cartilages   are
 spaces filled'with  additional  Cartilages,  the number
 size, and figure, varying in different  bodies.
   The elasticity of the Cartilages contributes  to the
 defence of the Nose against external injuries.
   The Nose  is covered by the common Integuments
 and perforated at its under and outer-part by the Duct'
 of sebaceous Glands, the contents of which may be rca'
d.Iy squeezed out by the pressure of the Fingers
   The Cartilages of the  Nose are moved indifferent
directions, by the following Muscles, which J,axe ltt,
already  described, viz. the  Cmx-c.t*-:-  Nari»,n  th 
                        49
 NasaJ purt of the Fretotal Musclf, the Levator and De-
pressor Labii Supetioris  Alaqui Nasi —The  Nose may
also be moved by the neighbouring Muscles, which, in
many instances, become assistants to the others.
  The internal Nares or Cavities of the  Nose extend
upwards to the Cribriform Plate of the Ethmoid, and to
the Body of the Sphenoid Bone.
  At the inner  side they are bounded by the Septum
Narium, which is formed by the Nasal Lamella of the
Ethmoid Bone, by the Vomer, and by the middle Carti-
lage  of the Nme.
  On the outside,  or  that next the Cheek, the Ossa
 Spongiosa project a considerable way into their Cavities,
and increase the Surface of the Membrane of the Nose,
 for enlarging the Organ of Smell.
  In animals which smell acutely, the Ossa  Spongiosa
are remarkably large and complex-
  The bottom of the Nostrils runs directly backwards,
so that a straight probe may be passed through either of
 them, to  the Throat
  in the fore-part of the Nostrils there are stiff" Hairs,
 called Vibrissa, which prevent the  Mucus  from con-
 stantly flowing out, and insects, or other extraneous
 matter from entering.
   The general Cavity of each Nostril is divided by the
 Ossa Spongiosa into three  Meatus, or Passages, which
 run from before backwards, and are described by Hal-
 ler according to their situations, viz.
  The Meatus  Narium Superior, placed  at  the upper,
 inner, and  back-part of the Superior Spongy Bone.
   The Meatus  Melius, situated between the Superior
 and Inferior Spongy Bones.
  'The Meatus Inferior, situated between the Inferior
 Spongy U'.tnc and bottom of the Nose
   The inside of the' Nose is lined with a thick Spongy
 Membrane, termed Mucosa, or Pituitaria of Schneider,
 or ^chneiderana, which lines the whole internal Nares,
 and is also continued  to the  different  Sinuses, to the
 Lacrymal  Sacs  and  P ilatine Ducts, to the Pharynx,
 Palate, ami Eustachian Tubes.
  This Membrane  is very Vascular and Nervous, and is
 the primary Organ of Smelling.   It is constantly lubri-
 cated and  preserved in a proper decree of moisture by 
                         so
the Mucous of the Nose, which is discharged upon its
Surface from numerous small Follicles.
.  The different Sina*** of the Bones of the Head, after
having run obliquely backwards in  a short winding di-
rection, terminate by small op< nings in the Cavity of the
Noss
  Tlie Frontal Sinuses pass downwards into the anterior
Ethmoid Cells, which terminate in the upper part of the
Nose, beh'.nd the beginning of the Lacrymal Sacs.
  Besides the Passages common to the Frontal Sinuses
and anterior Ethmoid Cells, there arc others  proper to
the PosteiorEthmoid Cells, which terminate in the up-
per :"i<r back-part of the  Nose near the openings of the
Sis.1''  u i:d Si;i'.ses.
   i he Spher.oi-t Sinuses  open, behind the Cells of the
F.'bmoid  Bone, into the upper and  back-part  of  the
Nose.
•  The Maxiliary Sinuses open at their tipper and inner
sid's,  bv one, and sometimes  two  passages, into  the
middle of the spice between the Superior and lnfe.ior
f- Mingy Bones, nealy opposite to the under edge of the
Orbits
  At tlie upper part of the Maxillary Sinuses, Appendices
described  bv Hai.lB".,  are sometimes found,  which
comm.r.'u ate with the  Ethmoid Cells
  Tik S des, or  Walls  of the Ma\illary Sinuses, are
formed o  thin Plates of Bone, excepting where the Pro-
C\ "9; .*> project and give them additional strength.   Be-
low, thev ha\e  only  t':in Pl.i'.es between  them and the
I/cnus Molares, the  roofs of which are sometimes found
to perforate the Sei'im
   ; he dii.erent rv'i-cs are  Tned with a continuation of
tl-  Memo) ana Sc/-;ciJeriana ; but in these it is thinner,
h -■. Vascular and Ner\oi s,  than that part of tlie Mem- \
brine wbicli lines the gcntrid Cavity of the Nose.       ^
  Thev are constantly  moit.lt ned, but not filled with a
fluid
   1 l.t- Sinuses ircrease and modulate the voice : Their
hollo  structure renders the Bones lighter; but they do .
not appear to constitute  part of the  Organ of Smell.
  Thc.r |-i:s.viges being directed backwards, prevent
any k.i.uof ixtrancous matter from getting into  them.  ■
  The Lacrymal Sac is  a Membranous Canal, situated 
                        51
m the Lacrymal Groove, formed bvthe Superior, Ma- •
diary, Lacrymal, and Inferior Spoiigv Bones.
•■ The Osseous Duct, in its descent, runs alittleobliqtiel.
backwards to the lower and lateral part of the Cavity of
the Nose, where it terminates at the inner and fore-part
of the Antrum Maxillare, under the Os Spongiosum Infe-
nus,a little behind the anterior extremitvof thatBone,and
Hi a direct line upwards from the second Dens /.lolaris.
  The upper part of the Osseous Passage forms only a
semi-canal, the under end a complete one.
  The Lacrymal Sac is situated in the upper part of the
Lacrymal Groove, behind the Tendon of the Orbicularis
Muscle of the  Eye-Lids.  About a fourth  part of the
Sac is situated above  the Tendon,  forming a kind of
intestinum Cacum, and  the rest is placed below.
  Towards the inner angle of the Eye, behind the Ten-
don of the Orbicularis Muscle, the Sac is perforated  by
the Lacrymal Ducts
  The under part of the Sac becoming a little narrow er,
but without  forming any Valve, passes into the  Nose,
Under the name of Lacrymal  Duct, Canalis  Nasalis, or
Ductus ad Nasum,  and terminates  at the inferior ex-
tremity of the Osseous Canal.
  The substance of the Lacrymal Sac and Duct is  si-
milar to thatof the  Membrana Schneideriana, is defend-
ed with the same kind of Mucus with which this Mem-
brane is lubricated, and is firmly connected to the Peri-
osteum of the Osseous  Canal.
  The use of this passage is,—to convey the superfluous
Tears to the  Nose,  so as to prevent them from passing
over the Cheek.
  The Ductus Incisivus, or Nasalo Palatinus of Steno,
is a small Canal, which,  as has been already observed
in the  description of the Bones, is only sometimes met
with in the Human Body, though it is always to be found
in the Ox, Horse, Sheep, &c.
  When present, it takes its origin  from a small Pit,
formed in the  fore-part of the  bottom of the Nostril,
under the termination of the Lacrvmal Duct.  It runs
obliquely downwards and forwards, placed in  such a
manner as to receive and conduct Tears iuto the Mouth.
   The Arteries of the Nose come chiefly from the ex-
ternal Carotids. 
52
  Those of the outer part of the  Nose come from the
Facial and Internal Maxillary Arteries;—those of the
inner, from the Maxillares Interns;—and a few twig*
are furnished by the Ocular Arteries-
  The Veins go  to the External Jugulars ;—they like-
wise communicate with the Ocular veins, and of course
with the Lateral Sinuses and Internal Jugulars.
  The Nerves with which the outer part of the Nose is
ehiefly supplied, come from tlie second branch of the
Fifth, and from the Portio Dura of the Seventh Pair.
  The inner part is principally supplied by the  First, or
Olfactory  Nerves, and by some  branches from  the first
and second portions of the Fifth Pair.
               OF THE EAR.

  The ear, or Organ of Hearing, is divided into the
External and Internal Ear.
                 External Ear.
  The External Ear comprehends the Auricle, or Ear,
properly so called, and the Meatus Auditorius Externu*.
  It is again divided into the Pinna, or Ala, which con-
stitutes by much the greater part of it;—and Lobus>
which is placed at its under end.
  The Pinna or Ala, is chiefly composed of Cartilage,
and is divitted at its fore-part, into seven I  Eminences
and Cavities, which have obtained particular names, viz.
  The Helix, or outer Bar, or Margin, so  called'fiom
its winding direction.  It arises behind at the Lobe of
the Ear, surrounds  its upper edge, and terminates  be-
low, nearly opposite to its origin, dividing the Concha
into two parts.
  'The Antihelix. Anthtlix, or inner Bar or Margin, which
is situated within the  former, and is composed supe-
riorly of two Ridges, uniting together below.
  The Tragus, so called fiomthe Hairs which frequenly
grow from it having a resemblance to the  beard  of a
Goat. 
                        53
  It is a small eminence which lies over the Meatus
Exterm'is', and is connected to the under and  fore-part
of the Helix.
  The Antitragus, so named from its being opposite to
the Tragus, below the posterior extremity of the Anti-
helix.
  The Cavitas Innominata,  situated between the Helix
and Antihelix.
  The Scapha, orFossa Navicularis,—compared in shape
to that of a Boat,—situated between the two limbs of
th^ Antihelix.
   The Concha, so called from its resemblance to a Fish-
shell of that name.  It is a large cavity under the An-
tihelix, divided by the Helix into two parts, the inferior
of which leads to the Meatus Auditorius.
  The back-part of the Kxternal Ear exhibits only one
considerable Eminence, whrch is the convex Surface of
the Concha.
  The Lobus, which  is the inferior soft part of the Ear,
is composed of Cellular  Substance, with a small quan-
tity of Fat.
   The Ear  is covered by a continuation of the common
Integuments, which is thinner here than on the rest of
the Body, and is perforated in many parts by the mouths
of Sebaceous  Ducts, which are placed immediately un-
der the Skin.
   The motions of the Ear, which are very limited, are
regulated by several Muscles, some of which are com-
mon to the Ear and Head, and others proper to the Ear
itself.  'The common Muscles  have been already de-
scribed.   'The Muscles proper to the Ear lie close upon
the Cartilage, and, in the generality of subjects, are so
thin, white, and indistinct,  as to receive from some Au-
thors the name of Muscular Membranes.—'They are ag
follow.
                   Helicis Major.
  Origin : From the anterior acute part of the Hells,
upon  which it ascends.
  Insertion: Into the Hel'x.
  Action: To pull that  part into which it is  inserted a
little downwards and forwards.
                   Helicis Minor.
  Origin ■ From the under and fore-part of the Helix 
54
  Insertion: Into the Helix, near the Fissure  in the
Cartilage opposite to the Concha.
  Action : To contract the Fissure.
                      Tragicus.
  Origin: From the middle and outer part of the Con-
elm, at the root of the Tragus, along which it runs.
  Insertion: Into the point of tlie Tragus.
  Action : To pull the point of the  Tragus a little for-
wards.
                    Antitragicus.
  Origin: From the internal part of the Antitragus,
upon which it runs upwards.
  Insertion : Into the tip of the Antitragus, as far as the
inferior part of the  Antihelix, where there is a Fissure
in the Cartilage.
  Action: To turn the tip of the  Antitragus a little out-
wards and  depress  the  extremity of the Antihelix to-
wards it.
                 Transversits Auris.
  Origin: From the prominent part of the Concha, on
the Dorsum, or back part of the  Ear.
  Insertion: Into the outside of the  Antihelix.
  Action: To draw  the parts to which it is connected
towards each  other, and to stretch  the Scapha and
Concha.
  The use of the External Ear is to collect  the  sound,
and convey it to the Meatus Externus,—the Muscles giv-
ing tension to  it, so as to render the  sounds more dis-
tinct
  The Cartilage of the External Ear is connected to the
Temporal Bone by the common Integuments, and by its
Muscles;  and is furnished  with Ligamentous  Mem-
branes, which fix it to the  roots of  the Zygoma  and of
the Mastoid Process.
  The \Meatus Auditorious Externus leads inwards, froth
the Concha, and in its course proceeds forwards ami up-
wards, turning a ittle downwards at its farthest extre-
mity, at the Membrana Tympani-—The turns, however,
are so  inconsidc.utile, that the  bottom of tiie passage,
can be  readily seen in  a clear light,  upon puling the
ear backwards. 
55
    It is somewhat of an oval form, a little contracted in
  the middle, and upwards of an inch in length.
    Its outer end, which is a continuation of the Concha,
  is Cartilaginous, and  has two or three Interruptions or
  Fiesures in it.
    On the upper and  back-part of its circumference,
  there is a Large Interruption terminating in an oblique
  Margin, which  is fixed to the rough edge, at the under
  part of the Osseous portion of the Meatus,
    At the upper and back-part of the Meatus, the Car-
  tilage has but little connection with the Bones,  being
  there fixed by the Skin which lines the Canal.
    The Osseous  Canal  is continued from the Cartilage
  of the Meatus, and is the longer oi the two, particularly
  at the upper and back-part of tfie Passage.
    The Meatus is lined with a continuation of the Skin
  which fills up the interruptions in the Cartilage, but is
  thinner than  on the rest of the Body.
   Under the  Skin of the Meatus, and near its outer end,
  there are numerous? small glands, of a yellowish colour!
  placed in  a Rect'mular Suhstance,  formed of the  Cor-
  pus  Mucosum, And termed Glandula Ccruminos* which
  discharge the Wax of the Ear through small Excretory
  Ducts.                                           f
   The Arteries of the External Ear come  Interiorly
 from the Temporal, and posteriorly from the  Occipital
 both of which are branches of the External Carotid Ar*
 tery.                                           **
   The Veins pass partly to the External, and partly to
 the Internal Jugulars.                      *    '
   The fore-part of the Ear is supplied with Nerves from
 the third of the Fifth, and from the Portio Dura of the
 Seventh  Pair ; the under and back-parf. by brandies
 from  the first  and second Cervicles.
  The Meatus Externus conveys the sound  from the
 Outer towards the Inner Ear/and  is supposed to du
 this to greater advantage, en account of the windinjr
 nature of the Passage.                             b
  The Wax lubricates the Passage,  and defends it from
the injuries of the air. and being of a viscid and bitter
quality, assists in the exclusion of insects
  Intlie Foetus, the Meatus is entirely  Cartilaginous,
     you.  1 1.           c                  q    ' . 
56
and only adheres to an imperfect Bony circle, in which
the Membrana Tympani is fixed.
  At the inner end of the  Meatus Externus, the Mem-
brana  Tympani is situated, which has its name from co-
vering the oater part of the Tympanum or Drum of the
Ear.
  It is firm, almost transparent, and of an oval form.
  It is fixed in a Groove which divides the Meatus from
the Tympanum.
  It is very tense, but has  a small depression in the mid-
dle next the Meatus, with  a corresponding convexity to-
wards the Tympanum, where the extremity of the Mai-
leus is fixed to it.
  Its situation is somewhat oblique, the upper-part be-
ing turned outwards, and the under inwards,  so that
the lower side of the Meatus is a little longer than the
upper.
  It forms a complete Septwm, and has no hole in it,
such as has been described by some Authors-          «
  It is formed partly of a  continuation of the  Lining of  <
the Meatus, but chiefly of the  Periosteum.
  The Membrana Tympani has numerous small Vessels
from the Temporal and Stylo-mastoid Arteries,  which
run in a radiated manner, and which are most abundant
in the Foetus.
  It is  the Conductor of  sound from the Outer to the
Inner  Ear.
  In the Foetus, this Membrane is fixed in an  imperfect
Ring of Bone, and, along  with the  Meatus, is covered
with a Mucous Membrane, which defends  the parts
from the too strong impulse of Sound.

              THE  INTERNAL EAR.
  The Internal Ear comprehends the Tympanum,  La-
byrinth,  and certain Passages leading into these.
  The Tympanum, or Drum of the Ear, is situated at
the inner side of the Membrana Tympani, approaches
to a Jiemispherical figure, and is about half an inch in
width.
  Between the Tympanum andCavity called Labyrinth,  '
there  is  an Osseous Septum, which forms the  bottom of
the Tympanum, where there are several Eminences, viz.
  The PromoMor-;, which forms the beginning of the 
Scala Tympani, and divi.i>:•  he Tympanum into ante-
rior and posterior region.-.
  A Protuberance at the  .:; ver and back-part of the
Tympanum, formed by the  Aqueducts Fallopii.
  A Projection,  called Eminentia Pyramidals Tympani,
situated behind the Fenestra Ovalis, in which is the
Passage for the Stapedius Muscle.
  An Eminence at the upper and fore-part of the Tym-
panum, containing a semi-canal, for lodging part of the
Tensor Tympani Muscle.
  In the Tympanum there are various Passages, which
communicate with the neighbouring parts, viz.
  The Iter a Palato ad Aurem,  or Eustachian  Tube,
which goes off from the upper and fore-part of the
Tympanum, and  runs obliquely forwards and inwards
to the posterior opening of the Nostril, and, terminates
at its outer edge, above the arch of the Palate.
  The posterior part-of the  Tube is formed in the Pars
Petrosa, at the upper and outer part of the Canal for
the Carotid Artery.
  The anterior portion is formed above, by the"1 Spinous
Process, and root of the Pterygoid Process of the Sphe-
noid Bone ;—and below, by Cartilage and Membrane.
  It is narrow next the Ear, where it can only admit
the point of a Surgeon's probe ; but becomes gradually
wider towards the  Nose, where it terminates by an ob-
lique opening  with prominent sides, sufficiently large
to admit a Goose-quill.
  It is lined by a Membrane similar to that of the rtose,
of which it appears to be  a continuation; and on the
edge of the Mouth of the Tube, it is so thick as to add
considerably to  its prominency.
  The Eustachian Tube preserves the balance of Air
between the Outer and Inner Ear, and prevents it from
pressing too  forcibly upon the different Membranes
placed in the sides of the Tympanum.
  It has been supposed to  convey the sound of a per-
son's own Voice to the Inner Ear ;  but experiment does
not favour this opinion, nor  is  it found to render Sound
more distinct  when the Mouth is open ;—though per-
sons who are dull of hearing are observed frequently to
listen after this manner.
  The Cells of the Mastoid Process,  which open into the 
                         5)8
 tipper and back-part of the Tympanum, opposite to, but
 a little higher than the Eustachian Tube.
   They are very irregular, and have many windings
 and turnings,  which communicate freely with each o-
 ther, and  are lined, like the Cells of other Bones, with
 the  Periosteum Internum.
   They assist the  Tympanum in reflecting the Sound.
   In Ojiadrupeds, which hear  acutely, there are large
 Cavities connected with the Tvmpanum,  which seem
 to supply.the place of Mastoid Cells.
   Above the Promotory, a Hole, called Fenestra Ovalis
 the upper and under edges of which are convex up-
 wards,—for lodging the  Base of the Stapes.
  The inner edges of this Hole  are contracted by a
 narrow border, upon which the end of the Stapes rests.
  Below the Fenestra Ovalis,  and at the under and
 back-part  of the Promontory, a Hole, smaller than the    i
 former, called Fenestra Rotunda.
  It is placed obliquely backwards, and outwards, leads
to the Cochlea, but is shut up by a Membrane which   <]
 assists in communicating Sound to the Labyrinth.
  The Sides, or Walls of  the  Tympanum, which like-
wise assist in  conveying Sound to the Labyrinth, are   'j
lined with Periosteum, which  is reflected  into the dif-
ferent  Passages leading from it.                       ',
  The Cavity  of the  Tympanum contains four small
Bones, called  Ossicula  Auditus, which  form a chain
stretching across from the Membrana Tympani  to the   '«.'
Labyrinth.
  The Ossicula Auditus are,—the Malleus, the Incus, the    t
Os Orbiculare,  and the Stapes,—these names being de-  " - j
rived from substances which they are supposed to re-   H
senible in  shape.
  The Malleous, or Hammer, consists of  a round Head,
a small Neck,  a Manubrium or Handle,  and two small
Processes, one in the Neck, long and very slender, and
therefore called Gracilis  ; the other in the upper end of
the handle, called Processus Brevis.
  The Handle  is by  some Authors considered as one of
the  Processes, and  is then called the longest of the   •'
three.  It forms an angle with the Neck, becomes gra-   .'
dually  smaller, and is bent, at its extremity,  towards
the Membrana Tympani. 
59
    In the natural situation, the Head is turned upwards
  and inwards, and the Handle down upon the Membrana
  Tympani, to which it adheres.
    The Incus, compared in shape to an Anvil, but more
  resembling one of the Dentes Molares, wfrh its roots
  widely separated,  is situated behind the Malleus, and
  is formed of a Body and two Crura of unequal lengths.
    The Body has a Cavity and two Eminences, corres-
  ponding to that part of the Malleus with which it is ar-
  ticulated.
    The Short Cms extends backwards, and is joined by
  a Ligament to the edge of the Mastoid opening.
    The long Cms is turned downwards, with the point a
  little flattened, and bent inwards.
    The Os Orbiculare is the smallest Bone of the Body,
  being considerably less than a grain of Mustard-seed.
    It is  articulated with the point of the long Process
  of the Incus, and is so firmly fixed to it, that in separa-
  ting the  small Bones of the Ear from each other, it is
  apt to adhere to the Incus, and has on  this account
  been frequently considered as a Process of that Bone.
    The Stapes is named from  a striking resemblance it
  has to a Stirrup.   It is divided into  Head, Crura, and
  Base.
    The Head is placed upon a small flat neck, and is ar-
  ticulated witli the  Os Orbiculare.
    The Crura, like those of the Incus, are unequal  in
>  length, and have a groove within, which is occupied by
  a Membrane.
    Tlie Base is of an oval shape) and has no perforation
  in it.  Its edges correspond with those of the  Fenestra
  Ovalis, with which it  is articulated.
    The Stapes is  placed  horizontally,  being nearly at a
  right angle with the inferior Crus" of the Incus.—Its
  two Crura are placed in the  same plane,—the longest
  backwards.
    The small Bones of the Ear are articulated with e.ach
  other by Capsular Ligament!,, propoitioned.to their size,
  and are covered by the Periosteum, which likewise fixes
  them to the  Membrana Tympani and Fenestra Ovalis.
    The small Bones have the following Muscles fixed to
  their, whic'i serve  for their different  motions.
                          »  2 
60
          Tensor  Tympani, or Internus Auris.
   Origin ■• From the Cartilaginous extremity of the Eu-
stachian Tube, near the entery of the  Artery of the
Dura Mater. From thence, its Fleshy Belly runs back-
wards in a Canal peculiar to it, at the upper and inner
part of the Osseous Portion of the Tube, being covered
only by  a  thin plate of Bone.  It sends off' a slender
Tendon, which makes a turn in  the Tympanum, and
passes outwards.
  Insertion: Into the  posterior part of the Handle of
the Malleus, a little below the root  of its long Process.
  Action:  To pull the  Malleus and  Membrana Tympa-
ni inwards, by which the Membrane is rendered more
concave and tense, and better adapted for the impres-
sion of weak sounds.
                   Laxator Tympani.
  Origin .•  By a very small beginning, from the extre-
mity of the Spinous Process of the Sphenoid Bone, be-
hind the entry of the Artery of the  Dura Mater ; after
which it runs backwards  and a little upwards,  at the
outside of the Eustachian Tube, in  a Fissure of the Os
Temporis, near the Fossa which lodges the Condyle of
the Lower Jaw.
  Insertion.- Into  the  long  Process of the Malleus,
within the Tympanum.
  Action :  To draw the Malleus obliquely forwards and
outwards, and thereby to render the Membrana Tym-
pani less  convex, or to relax it  when Sounds are too
strong.—Hauler  denies  the existence of Muscular
Fibres in this Substance.—Sab atier describes it, but
doubts of its Muscularity.
                     Stapedius.
  Origin -•  By a  small Fleshy Belly,  from a little cavern
in the Pars Petrosa, near the Cells of the Mastoid Pro-
cess. Its Tendon passes forwards through a small Hole
in that Cavern,  and goes into the Tympanum.
 . Insertion : Into the posterior part of the Head  of the
Stapes.
  Action ■■  To draw the  Head of the Stapes obliquely
upwards and backwards, by  which the posterior part
of its Base  is moved inwards,  and the anterior part 
                        61
outwards, and the Membrana Tympani thereby put up-
on the stretch.

                    Labyrinth.

  The Labyrinth, so  called from its Sinuosities and
windings, is situated at the inner-part of the Tympa-
num, and is formed of the Vestible, Cochlea, and Semi-
circular Canals, together with the Canalis Follopii and
Meatus Auditor ins Internus.
  The Vestible,  named from its forming a porch or en-
try to the Cochlea and Semi-circular Canals, is of an
oval figure, nearly of the size and shape of a clean grain
of Barley, and is situated at the inner side of the Base
ofthe Stapes.
  There are three contiguous Cavities in the Vestible,
one of which, the Semi-oval, is situated above ; another
the Hemispherical, below; and the third, or Sulciform,
which is tlie orifice of the  Aquxductus Vestibuli,  is
placed behind.
   In the Vestible there are several Holes which com-
nuinicate with the neighbouring parts, viz.
   The Fenestra Ovalis situated at the outside, by which
it communicates with the Tympanum.
   A round Hole, situated at the fore and under-part by
which it communicates with one of the Canals of the
Cochlea.
  Five Similar Foramina behind, by which it communi-
cates with the Semi-circular Canals.
  Next the Meatus Auditoriws Internus, it has four or
five  Cribriform  Perforations, for  the  transmission of
Nerves.
  The Cochlea is situated  ne?:t the anterior extremity
of the Os Petrosum, and at the fore-part of the Vesti-
ble,  in such a manner as to have its Base towards  the
Meatus Auditorius Internus, and its Apex in the oppo-
site direction,—or facing outwards.
  It has two Canals or Gyri, called Seal*, from a sup-
posed resemblance to  Stair-cases, tlie Gyri or turns of
which are very close to each other, and run in a spiral
direction, like the Shell of a Snail,from which the part
has obtained its  name.
  The Cochlea forms two Circumvolutions or turns and m
half, the first of which is much  larger and v ider than
                       D  3 
62
the other Turn and a half, which becomes  suddenly
smaller.                             '»
  The two  Canals are  upon the same level, the  inner
one next the Base, and the outer next the point of the
Cochlea.
  The Gyri go round a Nucleus, Axis, or central Pil-
lar, which is nearly horizontal, and is formed of two
hollow Cones, with their points turned to each other, die
one termed Modiolus, from its resemblance to the Spin-
dle of a  winding Stair-case, the other Infundibulum, or
Funnel.
  The Modiolus forms  the inner and larger portion of
the central Pillar, and is that Cavity seen in the under
and fore-part of the Meatus Auditorius Internus.
  It lodges that branch of the Portio Mollis of the So-
venth Pair  of Nerves, which goes to the Cochlea, and
is Cribriform, or full o.f small Holes for the passage of
the twigs of that branch.
  The Modiolus consists of two Plates, with numerous
Cells and Passages between them, and terminates in the
middle of the second Gyrus of the Cochlea.
  The Infundibulum is an imperfect Funnel, the Apex
of which is common with that of the Modiolus, and the
Base  is covered by the Apex of the Cochlea, which is
termed Cupola.
  Between the  Scalx of the Cochlea there is a Partition
called\Lamma Spiralis, or Septum Seal*, the larger por-
tion of which, next the Modiolus, is  formed of Bone »
The remainder, or that part next the opposite side of
the Scalae, is Membranous, and termed by Valsalva,
Zona  Cochl*.—This drops out  by maceration, so as af-
terwards to leave only a partial Septum.
  The Osseous part of the Lamina Spiralis is compo-
sed of two Extremely thinCribriform Plates, whichgradu-
ally approach each other at their opposite edges, where
they are perforated by numerous Holes.
  The termination of the Lamina Spiralis,  and of the
Scala Tympani, forms  a  Hamulus, or  small Hookj
which projects into the Infundibulum.
  One of the Canals or Scalxof the Cochlea, opens in-
to the under and fore-part of the Vestible, and is term-
ed Scala Vestibuli : The other, which is the smaller of
tlie two, communicates with the Tympanum  by the Fe-
nestra Rotum-h, i>d is called Scala Tympani. 
                         63
   Tlie Partition between the two Gyri or Turns of the
 Cochlea, like the Osseous part of the Lamina  Spiralis,
 is formed of two Platesr with a small Cavity between
 them.
   The Volute, or Spiral  of the Cochlea, begins below,
 runs forwards,  and then round, so as to form, as has
 been already mentioned, two circles or turns and a half,
 the direction of the Gyri corresponding with those ef
 the Shell of a Snail.
   The Canals of the  Cochlea are  conical, becoming
 gradually smaller towards the Anex, where they com-
 municate freely with each other/Through the medium
 of the Infundibulum.—This communication is called by
 Casseboiim, who gives  the fullest  Treatise upon the
 Ear, Canalis Scalarum Communis.,
   The  Semi-circular Canals are three in number,—the
 Superior or Vertical, the Posterior or Oblique,—and the
 Exterior or Horizontal.
   The Superior is placed transversely, in the upper part
 of the Pars Petrosa, with its convex side upwards.
   Tlie Posterior is farther back than the former one, and
 is parallel to the length of the Pars Petrosa, with the
 convex side turned  backwards.—One of its extremities
 is placed above, and the other below, the upper extremi-
 ty joining with the  internal one of the Vertical Canal,
 by which a common Canal is formed.
  The Exterior is less than the other two, which are
 more of an equal size,  is placed next the Tympanum,
 and has its extremities and curvatures nearly upon the
 same plane; with the curve placed backwards.
  Each of the Canals forms upwards of three-fourths of
a circle, can admit the head of a small Pin, and has an
Enlargement, Ampulla, or Cavities Elliptica, atone end,
the other extremity being nearly of  the same size with
the rest of the Canal.
  The Orifices are only five in number, two of the Canals
having a common termination.  Of these Orifices, three
are situated at the inside, and two at the outside of the
Vestible, into the posterior part of which they open.
  In the bottom of the Meatus Auditorius Internus,
which is situated in the posterior Surface of the Pars
Petrosa, there is a large under, and a small upper Fot->
 '••'■'■'i scp.-alcd by a sharp Kidge.
                           d' 4 
                       64
  The fore-part of the inferior Fossula lead s towards the
Cochlea, and is perforated with numberless Small Holes,
through which branches  of the Portio  Mollis of the
Seventh pair of Nerves pass to the Cochlea.
  One  Hole in the centre, larger than the rest, trans-
mits a branch of that Nerve to the Infundibulum.—This
Hole, however, is frequently enlarged, in consequence
of the  Bone, which is extremely thin,  being  broken
while preparing it.
  In the back-part of the inferior Fossula, three or four
Cribriform Holes apjAftr, for the transmission of branch-
es of that part of the Portio Mollis destined  for the
Vestible and Semi-circular Canals.
  In the upper Fossula of the  Meatus Internus, there
are two Passages, one posterior and smaller,  transmit-
ting Nerves into the Elliptical Cavity of the Vestible.
  The  other, the anterior and largest, is termed Canalis
or Aquaductus Fallopii,—from a resemblance it bears to
an Italian  Aqueduct, and  serves for a transmission of
the Portio Dura of the Seventh Pair of Nerves.
  The  Canal of Fallopius  goes through the upper-part
of the Pars Petrosa, passes downwards and backwards
between the Foramen Ovale and external Semi-circular
Canal,  and terminates in the Foramen  Stylo-Mastoi-
deum.
  In its passage though the Pars Petrosa, it communi-
cates with the Foramen Innominatum, situated on the
upper and fore-part of the Process.
  In Children, the Labyrinth is almost  as large as in
Adults, its Substance complete and hard, while  the
Bone which surrounds it  is soft and spongy; on which
account it is easily separated from the rest of the Pars
Petrosa.
  The  different Cavities and passages of the Labyrinth
are lined with the  Periosteum, which in the Vestible
tills the F'enestra Ovalis, and of consequence covers the
Base of the Stapes.
  The  Periostea of the two Canals of the Cochlea form,
by their union, the Membraneous portion (if the  Lamina
Spiralis, which, together with the Osseous part, com-
pletes the Septum between the two Seals.
  The  Periosteum of the Cochlea  also  assists that of
:lie Tympanum, in farming the Membrane of  the  Fc- 
65
 nestra Rotunda, and which is sometimes called Mem-
 brana Tympani Secundarii, from a resemblance to the
 Membrani Tympani, and from being, like it, a little
 concave on the outer, and convex on the inner Surface,
 or where it faces the Scala to which it belongs.
   Besides the Periosteum, the Vestible,  Cochlea, and
 Semi-circular Canals contain a Pulpy  Membrane, upon
 which the  Portio Mollis is irregularly dispersed.
   In the Vestible, the Pulpy Membrane forms a Sac, in
 shape resembling that of the Osseous Cavity which con-
 tains it, and which is described and beautifully deline-
 ated by Scarpa.
   When the Sac is laid open upon the upper and outer-
 part, a Partition appears, of the nature of the Sac, term-
 ed by Dr. Meckel, Septum VestibuliNervoso Membra-
 naceum.
   In the Cochlea, the Pulpy Membrane  is in contact
 with the Periosteum, but can be separated from that
 Membrane without much difficulty.
   In the Semi-circular Canals, it is at some distance from
 the  Periosteum of these Bones, and is  considerably
 smaller, but, like them, it forms distinct Tubes, which
 communicate with the Vestible.  Like  the  Osseous
 Canals also, the Membranous Canals form Ampullae, or
 Elliptic Cavities at one end.
   The  Arteries of the Labyrinth arise by one or two
 small branches, chiefly from the Vertebral Artery, and
 pass through the Cribriform Plate, at the bottom of the
 Meatus Externus which belongs to the Labyrinth.
   From the Labyrinth one or two Fein* return, and ter-
 minate in the end of the Lateral Sinus.
   The Cavity of the Vestible contains no Air, bit is
 constantly filled with a  Watery Fluid, supposed to be
 secreted from the Arteries of the Periosteum, and
 which is found to resemble the Aqueous Humour of the
 Eye.
  The Aqueous Fluid fills the Vestible  and Scalaeof the
 Cochlea, and likewise surrounds the Membranous Se-
 mi-circular Canals.
  The Aqua Labyrinthi is considered as a medium  by
which  sounds are commdnicated from the Membrane
filling the round and oval Holes, and from the Base of
the Stapes to the  Pulpy  Membranes placed in it. 
66
  The superfluous part of the Aqua Labyrinth! is sup.
posed by Cotunnius to be carried off by two small Co-
nical Ducts, more particularly described by him than by
some  preceding Anatomists,  who were partly acquaint-
ed with them, but considered them as Blood-vessels.
  One of the Aqueducts of Cotunnius,  called Aqua-
ductus Cochlea, begins at  the under  part of the Scala
Tympani, near the Fenestra Rotunda, and after passing
through the  Pars Petrosa, is seen, in  the figures  he
gives  of it, terminating  by a wide triangular opening,
upon the surface of the Dura Mater, between the pas-
sages of the Seventh and Eighth Pair of Nerves.
  The other Duct,  called Aquaductus Vestibuli, begins
under the termination of ^he common Canal, in the Ves-
tible from which it descends, and terminates by a tri-
angular  opening between the Layers of the Dura Ma-
ter, behind the Meatus Internus, and balf-way between
the upper edge of the Pars  Petrosa and Diverticulum
of the Internal Jugular Vein.
  For a full account of these Ducts, and the  other  parts of
the Labyrinth, see a Description of them by Dr. Mec-
kel,  of Berlin.
  The Nerves of the Labyrinth are derived  entirely
from  the Seventh Pair.
  The Auditory Nerve is composed of two branches, one
of which is called Portio Dura, and is harder than the
other, termed Portio Mollis.
  The Trunk of the Auditory Nerve passes into the
Metus Externus, covered by the investing Membrane
of the Brain.
   The Portio Dura  goes through the Canalis Fallopii,
sending off,  in its passage, branches  through Perfora-
tions  in its sides, to the Stapedius Muscle and Mastoid
Cells.
   One reflected branch  passing  through the Foramen
Innominatum, in the Pars  Petrosa, forms a connection
between the Portio  Dura and the second part of  the
Fifth  Pair.
   Another, called  Chorda  Tympani, passes across  the
Cavity of the Tympanum,  between the inferior Crus of
the Incus and handle of the Malleus, and at the. outside
iff the Eustachian Tube, to join the Lingual branch of 
67
the Fifth Pair.  In its passage it supplies the Muscles
of the Malleus and Membranes, &c. of the Tympanum.
  The remainder of the Portio Dura is dispersed upon
the Face.
  The Portio Mollis is divided into two principal parts,
one to the Cochlea, the other to the Vestible.
  The branches of the Cochlea pass through the Cri-
briform Plates of the Modiolus, to the Pulpy membrai i::
lying in the Scabx.
  The branches run between, and likewise on the out-
side of the Partitions which divide the Cochlez into
Gyri, and the Gyri into Scalx, and are large and nume-
rous in proportion to the part they supply.
  The largest and  most numerous of these branches
are dispersed upon  the Lamina'Spinalis,  where they
form an intricate Plexus, the Threads of which are  at
first opaque, but are  afterwards of the colour of the,
Retina of the Eye.
  The branches terminate, and appear also to meet up-
on that part of the Pulpy membrane,  which is most
distant from the Modiolus.
  Through the Cribriform  Plate, common to the Mo-
diolus and Infundibulum, the last branches of this por-
tion of the Nerves pass, to be spread out upon the Mem-
brane lying  within the  Infundibulum.—For a particular
description of that part of the Portio  Mollis distributed to
the Cochlea,  and of the  Cochlea itself, see Dr. Monro's
Treatise an the Ear.
  Of that part of the Portio   ollis destined for the Ves-
tible and Semi-circular Canals, one branch goes through
the posterior Hole in the upper-part of the Meatus In-
ternus ; the rest pass through the holes in the under
and back-part of the Meatus, already pointed out in the
description of that Passage.
  After perforating tlie Foramina, the Nerves are seen
first in distinct Plexus, but become afterwards trans-
parent, and are lost upon the Sac contained in tlie Ves-
tible and upon the Ampulla of the Membranous Semi-
circular Canals.
  The Portio Mollis is  the primary part of the Organ of
Hearing,  to which all  the other parts are subservient,
and may be regarded as being of  the same service to
the Ear, as the Retina is to the Eye. 
MOUTH, TONGUE, AND THROAT,

       WITH THEIR APPENDAGES.
                    MOUTH.

  THE Osseous Parts of the Mouth are,—the Ossa Max-
'■'laria Super tor a, the Ossa Palati, the Maxilla Inferior,
and the  Teeth;—all of which  have been already de-
scribed.
  The Soft Parts of the Mouth consist of the Lips anc
Cheeks, the Gums, the Palate, the Velum Palati, the
Uvula, the Tongue, the Membrane lining the Mouth and ^
the Salivary Glands.
  The Lips and Cheeks are principally composed of Mus-
cles, are covered on the outside by the common integu-
ments, and lined within by the membrane of the Mouth,H
under which there are numerous mucous Glands* which
obtain their names from their situations.
  The intervening space between the Masseter and Buc
cinator Muscles is occupied by a large quantity of Fall
which gives form to the Face.
  The Membrane ofthe Mouth is covered with fine Villi{
but these are most conspicuous upon the edges of the
Lips, as may be readily seen after a fine injection, or
after masceratingthe parts till the Cuticle can be sepa-
rated.
  From the edges of the Lips, the Common Integu-
ments (now become extremely thin) are converted into
the Membrane whicli is continued into the Cavity ofthe
Mouth,  and which, opposite to the Dentcs Incisores of
the upper and under Jaws, forms a small doubling or
Franum, which fixes the Lips more firmly to the Jaws.
  The Lips arc serviceable in the general purposes of
Speaking, Eating, Drinking, kc.
  The Gums  cover the sides ofthe /> V:olar Border of
4 
69
both Jaws, pass in between the different Teeth, and sur-
round and adhere firmly to the Collar of each.
  The Substance ofthe Gums is of a dense nature, very
Vascular, and the Vessels united by a compact Cellular
Substance.
  They may be said to consist of the common Mem-
brane of the Mouth and the Periosteum of the Jaws
intimately connected.
  They serve as a covering to the Jaws and assist in the
security ofthe Teeth.
  The Arteries ofthe Lips, Cheeks, and Gums, are from
the Facial,  Temporal, and Internal  Maxilaries, which
are derived from the External Carotids.
  The Veins go chiefly to the External, and partly to the
Internal Jugulars.             •
  The Nerves come from the first and second  branches
ofthe fifth Pair, and also from the Portio Dura of the
seventh Pair.
  The Palate is divided into the Palatum Dure and Pa-
latum Molle.   The former is composed of the Palate-
plates ofthe upper Jaw, and is covered by the Perios-
teum and common Membrane ofthe Mouth, which pre-
vent the Bones from being injured.
  The Membrane which covers the Bones of the Palate
forms numerous Rug*, which assist in the division ofthe
Food.
  It is nearly of the same structure with that of the
Gums, but perforated  by the Ducts of the Palatine
Glands, for the excretion of Mucus, which  serves to
lubricate the Palate, and assists in dissolving the Food.
  ThvPalatum Molle, Velum Pendulum Palati, or Soft
Palate, is that part which depends from the  posterior
edge of the Ossa Palati, and from the Pterygoid Pro-
cesses ofthe Sphenoid Bone, and forms a partition be-
tween the Nose and Mouth.
  It is composed of the Membranes which line the Nose
and Mouth, and of the expansions of the Circumflex
and  Levator  Palati Muscles, and numerous Mucous
Glands which serve to lubricate the Mouth and Throat,
and facilitate deglutition.
  The Palatum Molle conducts the Fluids of the Nose
into the Mouth, and acts like a valve in preventing what
we swallow from passing into the Nose. 
70
  In the middle of the posterior edge of the Velum
Palati, the Uvula or Pap of the Throat, takes its origin,
and hangs pendulous, from the Velum over the root of
the Tongue.
  It is of a Conical form, is covered by the Membrane
ofthe Mouth, and has a small Muscle within it, by which  j
it is elevated and shortened,—its other motions depend-
ing upon the Muscle ofthe Palate.
  The use ofthe Uvula  in Speaking and in Deglutition,
is evident from the inconveniencies which result from
its being destroyed by disease.                     .
  The Arteries of the Palate, &c. come from the Facial,
and Internal Maxillary.
  The Veins go into the  External and Internal Jugulars.
  The Nerves  are chiefly from the second to the fifth,  «(
with some twigs from the eighth Pair.

                      Tongue.
  The Tongue is of an Oval Form, and is divided into*
Base, Body and Apex.
  The Base, or posterior part of the Tongue, is connect
ted to the Os  Hyoides, and by the medium of this, to
the adjacent Bones and Muscles.
  The Body, or middle  part of the Tongue, terminates
anteriorly in the loose moveable point.
  On the Dorsum  or upper Surface, there is a Linea
Mediana, or middle Groove, running longitudinally, attd^ ■
dividing it into two lateral convexities.              ',*
  The inferior Surface, which reaches only from the
middle ofthe Tongue to the  point, is connected to the
parts  below it  by the Sublingual Ligament, or Franum
Lingua, which is a doubling ofthe Skin, or lining of the
Mouth.
  The sides ofthe Tongue are fixed to the Lower Jaw
and Styloid Processes, and parts adjacent, by Membra-
nous Ligaments.
  The Tongue is chiefly composed of the Fibres of the
Muscles which serve for its motions.—These Fibres are
disposed in various directions, and intermixed  with a
Medullary Fat.
  The upper and lateral parts of the Tongue are com-
posed of the Stylo-Glossi.—Its middle portion, between
the two former Muscles, is formed of the Linguales.r*- 
n
The lower part is chiefly formed ofthe Genio.Glossi ;—
and behind, the Stylo-Glossi enter into its composition.
  The Tongue is covered by a continuation ofthe com-
mon Integuments, which are preserved  soft and moist
by the Saliva.
  The Cuticle forms Vaginae for receiving the Substan-
ces called Papilla.
  The Corpus Mucosum ofthe Tongue  is thicker than
in other parts of the Body, but more moist.
  The third covering ofthe Tongue, the Cutis Vera, t%
remarkably Nervous.—The Papillae, which take their
origin from it are very  Vascular, especially near the
Apex of the  Tongue, but are a wanting on its under
Surface.
  The Papilla are divided into three kinds, the Maxi-
ma, Medi*, and Minim*.
  The first class, called Papilla Maxima, Lenticulares,
or Capitatx, are by much the largest, and of a Lenticu-
lar form, having round Heads and short  Stems.
  They are placed at the Base of the Tongue, in super-
ficial  Fossula, and are dispersed in such  a manner as to
form  an angle with  its point backwards.
  They are glands of the Salivary kind,  and have each
of them a small Perforation in tlie middle of its convex
Surface, for the excretion of Mucous.
  Besides tlie Papillae Capitatse, there are numerous
Mucous Follicles, which cover the greater  part of the
Surface of the root of the Tongue.
  At the root of the Tongue, and behind  the angle form-
ed by the Papillae Maximx, there is a Hole, called Fora-
men Cmcum of Morgaoni, by whom it was first de-
scribed.
  It penetrates only a small way into the Substance of
the Tongue, and receives the Mouths of several Excre-
tory Ducts which terminate in it.
  The second  class  called Papilla Media, or Semi-:e».
ticulbres, are  much smaller than the former, and are
scattered over the upper Surface of tho Tongue at some
distance from each other.
  They are of a Cylindrical form, and terminated by a
round extremity.
  The third class, termed Papilla Minima, or Conic*,
or Villosa,  are by mueh the most numerous, but \ci • 
 minute.  They occupy almost  the whole  upper Sur-
 face of the Tongue, but are most abundant towards the
 Apex, where the sensation of Taste is most acute.
   This and the second class have  been  supposed to be ,
 formed chiefly of the extremities of Nerves, and to con-
 stitute  the real Organ  of Taste ; though other, parts, as '
 the Palate, and even the Pharynx and Esophagus, pos-
 sess the faculty of Taste in a certain degree.
   The  principal Blood-Vessels of the Tongue are-large
 in proportion to the size of that Organ.
   They are called  Linguales, or Ranin*, on account of
 the dark-coloured branches which appear under the
 Tongue.
   The  Arteries, which are branches  ef the External
 Carotids, are not found to communicate so freely (m
 the opposite sides of the Tongue, as  they do in otherj-
 parts of the Body.
   The  Veins open chiefly into the External Jugulars.
   The  Nerves like the Arteries, are large and numerous,
 and have little connection on the opposite sides.
   They come from the Fifth, Eighth, and Ninth Pairs.
   The  first set supply the parts next the  point of the
 Tongue, and are therefore considered as being princi-
 pally concerned in conveying the sensation of Taste.
   The  second set supply the root, and the third the mid-
 die ofthe Tongue, and  are chiefly dispersed upon its'
 Muscles__There is a considerable intermixture, how-
 ever, between the three sets on the same side.
   Besides  being the  principal Organ  of Taste, the
 Tongue is the chief instrument of Speech, and of the
 articulation of the Voice,—It also assists in Manduca-
 tion, Deglutition, Spitting, Sucking, &c.
   The  Salivary  Glands  consist of three  large Glands
 on  each side of the Face, viz.—the  Parotid, the Sub-
 maxillary,  and the Sublingual,-—besides  many  small
. Glands, named from the parts to which they belong.   i
   They are of a  yellowish colour, and irregular on their
 Surface, being ofthe  Conglomerate kind.
   The Parotid Gland, which is the largest ofthe Saliva-
 ry Glands,  is named from its situation near the Ear.
    It occupies the whole space between the Ear, Mas-
 toid Process, and the  angle ofthe Lower Jaw. 
73
   It extends superiorly to the Zygoma, and. anteriorly
 to the Masseter Muscle, part of which it covers.
   The under end of it lies contiguous to the Submaxil-
 lary Gland.
   From the different parts of the Gland, numerous
 small Branches arise, which  join together to form  a
 large Duct,  sometimes called Steno's Salivary Duct,
 or Ductus Superior, which  passes from the upper and
 fore-part of the Gland.
   The Parotid Duct is of a white colour and large size,
 but, from the thickness of its coats, the Cavity is small
 in proportion to the outside ofthe Duct.
   It passes anteriorly, in a transverse direction, over
 the Tehdonof the Masseter  Muscle, by which it is free
 from compression,  and descends a little to perforate
 the Buccinator Muscle, opposite to the second or third
 Dens Molaris ofthe Upper Jaw.
   In crossing the Masseter Muscle, it receives some-
 times one, sometimes two  minute Ducts, from an equal
 number of small Glands, called  by Haller, Glandula
 Accessori*.
   The Inferior Maxillary, or Submaxillary Gland,  is
 smaller and  rounder than the Parotid, and  is situated
 on the  inside ofthe angle of the lower Jaw, between
 it and the Tendon ofthe Digastric Muscle.
   From the upper and fore-part of this Gland, a Duct
 arises, called by some Authors Ductus Whartonii, or
 Ductus Inferior, which  is  much thinner in substance
than the former Duct, but longer.
   It passes forwards between the Mylo-Hyoides and
 Genio-Glossus Muscles, along the under and inner edge
of the Sublingual Gland,  to the side of the Frzenum
Linguae, and terminates behind the Dentes Incisores,
by a small orifice, in form of a PapilH.
  The Sublingual Gland is smaller and softer than the
Submaxillary, andi.-; flat, and of an-oval form.
   It is  situated under the anterior portion  of the
Tongue, above the Duct ofthe inferior Maxillary Gland
near the Lower Jaw, between the Mylo-Hyoides and
Genio-hyogiossus Muscles,  the  former of  which sus
tains it.
  Its extremities are  turned forwards and bacl:wa d.  .
and the edges obliquely inwards and outwards.
     vol..  1 1,           £ 
74
  It is covered by a continuation ofthe Skin ofthe un.
der side of the Tongue,  which fixes  the Gland in its
place.
  It opens by several orifices arranged in a line near
the Gums, a little to the outside ofthe Fracnum.
  In many Quadrupeds, there is a distinct duct belong-
ing to this Gland, like that of the Submaxillary.
  Sometimes this Gland sends off a Branch which com-
municates with that ofthe Submaxillary, but generally
it is otherwise
  The smaller Glands of the Mouth are in great num-
bers, lying between the inner lining of the Mouth and
its Muscles, and deriving their names  from their situa-
tions.
  They are small simple Glands, each sending a duct,
which perforates the Skin of the Mouth, and opens in-
to its Cavity,—They consist of—
  The Buccales, which are placed all  over the Cheek,
but most plentifully near the termination of the Parotid
Duct ;
  The Labiates, lying on the inside of  the Lips ;
  The Palatinx, upon the Palate ;  and
  The Linguales, at the root of the Tongue.
  The Arteries of the Salivary Glands are from different
Branches of the External Carotids.
  The Parotid is supplied from the Temporal, the In-
ferior Maxillary from  the Facial, and the  Sublingual
from the Lingual Artery.
  The Veins of these Glands  go to the External Jugu-
lars.
  Their Nerves are chiefly from  the  third part of the
Fifth, and from the Portio-Dura of the Seventh Pair.
  The Salivary Glands serve for  the  secretion of the
Saliva, which they pour out in large quantity, and which
is promoted by the motion  of the  Lower Jaw.—The
Salva assists in the solution of the  food in the Mouth,
in lubricating the throat for its passage downwards-, and
in the digestion of it in the Stomach. 
THROAT.
  The Throat consistsof the Arches ofthe Palate, ofthe
Pharynx and Larynx, with the Muscles, Vessels,  Nerves,
&c which surround them.
  The Arches  ofthe Palate are two in number, in each
side of the Throat, one of which is termed the Anterior,
the other the  Posterior.
  They are formed  of a doubling of the Skin, with a
few featured Muscular Fibres.
  The Anterior arises from  the  middle  of the Velum
Palati, at the side ofthe Uvula, and is fixed to the edge
ofthe Base ofthe Tongue.
  The Posterior has its origin likewise from the side of
the Uvula, and passes downwards, to be inserted into
the side of the Pharynx.
  The Anterior Arch contains the Circumflex Muscle
of the Palate, and, with its fellow on the opposite side,
forms the  opening into the Throat, called Isthmus Fau-
cium.
  The Posterior Arch has within it the  Levator Mus-
cle ofthe  Palate.
  Between the Anterior and  Posterior Arches,  and
close by the sides of the base  ofthe Tongue, the Amyg-
dala,  Tonsils, or Almonds of the Ears are situated.
  They are of a reddish colour,of the figure of Almonds,
full of Cells which  communicate with each other, and
have large irregular openings, which convey the Mucus
into the Throat, the discharge of which is promoted by
the motion of the surrounding parts.
                     Pharynx.
  The Pharynx, so called from its conveying food to
the stomach, and Air to the  Lungs, is a large Muscu-
lar Bag, in form of an irregular Funnel, with the Tube
called Esophagus descending from it,  and forming the
under end of that Funnel.
  It is bounded above by the Cuneiform Process of the
Occipital  Bone, the Pterygoid Process of the Sphenoid
Bone, and backpart ofthe Jaws,  with all of which it is
intimately connected. 
re
   'he anterior margins of its Fleshy parts are connec-
ted to the edges of the Larynx, and its sides are co*
Vered by the great  Blood-vessels ofthe Neck.
  The fore-part of the Pharynx is formed by a Mem-
brane common to it and to the back-part of the Larynx.
  Behind, it lies flat upon the Cervical Vertebrae, and
upon the Muscles which cover the fore*part ofthe sides
of these Vertebrae.
  It has several Openings by  which  it communicates
with neighbouring  Cavities.
  Two of these lead upwards and forwards by the pos-
terior Nares into the  Nose;—two go laterally by the
Eustachian Tubes  to  the Ears;—one passes forwards
through  the large  opening, termed  Fauces, or top of
the Throat, to the  Mouth ;—one goes downwards and
forwards, through  the Larynx  and  Trachea,  to  the    ;
Lungs  :—and another  directly downwards by the Eso-   j
phagus to the Stomach.
  The Pharynx is surrounded by  a loose Cellular Sub-
stance, and consists of different Layers of Muscles, cal-  I
led Constrictores Pharyngis,  which have  been already
described.
  On the inner side, it is lined by the continuation of
the Membrane of the  Mouth, which is  perforated by
the Ducts of numerous Glands, for the secretion of
Mucus.
  The  lower end ofthe Pharynx, opposite to the under
edge of the  C icoid Cartilage,  describes  a complete
circle whicli  forms the beginning of the Esophagus.
  The  Pharynx is supplied with  Blood by the  Pharyn-
geal Branches, w hich come directly  or indirectly from
the External Carotids.  It returns its blood to both Jug-
ular Veins.—Its nerves are from the Eighth Pair.
   1 he  Use ofthe Pharynx is,—to receive the Aliments
from the Mouth, and by the action  of its Muscles to
convey them to the Esophagus.  It must likewise assist
in the modification ofthe Voice.

                      Larynx.
  The Larynx, so  called from its being the principal
Organ of Voice, is  situated at the upper and fore-part
ofthe Neck immediately under the Os Hyoides, which
it placed at the root ofthe Tongue. 
77
  It is composed of Cartilages and Muscles, Ligaments,
Membranes, and Mucous Glands;  and is connected a-
bove to the Tongue and Os  Hyoides, and behind to the
Pharynx.
  The Cartilages ofthe Larynx are generally consider-
ed as being five in number, though  besides these, some
choose to enumerate small Projections which  are con-
nected with them.                              ,
  The Five Cartilages are,—the  Thyroid, the Cricoid,
the Two Arytenoid, and the Epiglottis.
  The Thyroid, Scutiform,  or Shield-like Cartilage, is
placed at the upper and fore-part of the Larynx, and is
the largest ofthe whole.
  When spread out, it is of an oblong shape, but in  the
natural  situation, it consists of two lateral Wings or
Portions, of a quadrangular  form  uniting before in a
longitudinal angle, which can be readily felt in the fore-
part ofthe Throat, and which, from its projecting more
in Men than in Women, has obtained the name of  Po-
tnum Adami.
  The upper part of the angle is formed into  a Notch,
from which, and from the upper edge of the Cartilage
in general, a  broad Ligament ascends, to fix it to  the
under-part ofthe Os Hyoides.              '
  From the posterior corners four processes project,
called Cornua, two of which termed Superior, are long,
and ascend to be joined by round Ligaments to the  ex-
tremities of the Cornua ofthe Os Hyoides.
  In the middlo of these  Ligaments, one or two small
Cartilaginous, or even Osseous Substances, are fre-
quently found.
  The other two Cornua, called Inferior, are shorter
than  the  Superior, and curved backwards, to be fixed
to the sides ofthe Cricoid Cartilage.
  The Thvroid Cartilage serves for the protection of
the other  Cartilages, and, along with the Os Hyoides,
preserves the Passage open, for the transmission ofthe
Food to the Stomach.
  The Cricoid, or  Annular, or Ring-like  Cartilage, is
placed  below, and likewise behind  the  Thyroid,  and
like it', may be readily felt in the fore-part  of  the
Throat.
   It is narrower before, where it  lies under the Tny'- 
                        78
roid Cartilage, and thick, broad and strong posteriorly,
where it is placed behind that Cartilage.
  Its  Posterior Surface is divided by a Ridge into two
lateral Cavities, for the reception ofthe posterior Cricg
arytenoid Muscles.
  Its  under edge is horizontal, and fixed  to the begin-
ning,  or first Cartilage of the Trachea.
  The upper edge slants considerably, and has its an-
terior narrow part fixed to the under edge of the Thy-
roid Cartilage.
  It has four small Articular Surfaces,  with distinct
Capsular Ligaments, of which two are placed above, for
the articulation of the Arytenoid Cartilages, and two at
the under and lateral parts, for the connection of the in-
ferior Cornua ofthe Thyroid  Cartilage.
  The Cricoid  Cartilage  forms part  of the general
Tube of the Trachea, consitutes the Base ofthe La-
rynx, and gives a firm support to the Arytenoid Carti-
lages.
  The two  Arytenoid Cartilages, named from a supposed
resemblance to  an  Ewer, or Drinking-cup ofthe An-
cients, are  much smaller than the other Cartilages, and
are placed  upon  the upper posterior,  and lateral parts
of the Cricoid Cartilage, at a small distance from each
other.
  They are of a triangular form, and  a  little twisted,
and are bent back, so as to have a  broad concave Sur-
face behind.
  Their upper extremities are turned towards each o-
ther,  and are considered by some  Authors as distinct
Cartilages.
  Their Bases are broad and hollow, where they are ar-
ticulated by Capsular Ligaments with the Cricoid Car-
tilage, upon which they are moved in different direc-
tions, by the action of various Muscles,
  They are connected to each other, and to  the  adja-
cent Cartilages, by different Muscles and Ligaments.
  The Arytenoid Cartilages form a part of the opening
called Glottis,  and give attachment to its Ligaments.
   The Epiglottis, obtaining its name from its situation
above the Glottis, is of an oval form when  surrounded
by its Ligaments and Membranes, but, when divested 
79
of these, it is found to be narrow below, broad above,
and rounded at its upper extremity.
  It is convex towards the  Tongue, and concave to-
wards the Glottis, with its point reflected a little for-
wards.
  It is placed behind the  upper part of the Thyroid
Cartilage, is situated obliquely  over the Glottis, and
may be  seen and examined by pressing'down the root of
the Tongue.
  Its under end is fixed by a broad and  short Liga-
ment to the middle  Notch of the  Thyroid Cartilage,
and by  two lateral Ligaments to the whole  length of
the Arytenoid Cartilages.
  It is fixed to the roots ofthe Os Hyoides and Tongue
by another Ligament, whicli is a doubling ofthe inner
Membrane running along the middle  of  its anterior
Surface, and forming the Frxnum Epiglottidis.
   It is  very elastic, and is much more pliable than the
other cartilages,  being of a  Cartilago ligamentous na-
ture.
   It is  found to  have a number  of Fissures, in  which
 Lacuna are placed,  and to be perforated by  numerous
 Foramina, which are  the Mouths of so many Mucous
 Follicles, and which are in a great measure  concealed
 by the  Membrane which covers it.
   It breaks the current  of  the  Air coming from th'e
Mouth  and Nose, and prevents it from rushing too for-
cibly into the Cavity of the Lungs.—Pressed  and drawn
down by the Tongue and by small Muscles, it defends
the Glottis, and shuts it completely in the time of swal-
lowing. After the Action of swallowing, it is raised by
its own elasticity, and by the root ofthe Tongue to
which it is fixed, returning to its former position.
   Ligaments ofthe Glottis.—From the fore-part ofthe
body of each ofthe Arytenoid Cartilages, a Ligamen-
 tous Cord passes horizontally forwards, to be fixed by
 its other extremity to the inside of tlie anterior angle of
 the Thyroid Cartilage.
   The  opening formed between these Ligaments is cal-
 led Glottis,, from the Greek : It is also called Month of
 the Larynx, and Rima Glottidis, and is of a triangular
 figure, the Ligaments being at a greater distance be
 hind than at their anterior extremity.
                       F  3 
                        80
   Under these two  Ligaments there are twP others',
 larger and more distinct than the former, and which are
 commonly considered as the proper Ligaments of the
 Clottis. They  arise from the Base of the Arytenoid
 Cartilages,  and run in the same direction with the for-
 mer, to be fixed also to the Thyroid Cartilage.
   In the Interstice of the Superior and Inferior Liga-
 ments, on each side there is  a Fissure, which leads to a
 small Membranous  Cavity or Depression, with its bot-
 tom turned outwards.
   These are the Ventricles ofthe Larynx of Galen.—
 They are chiefly formed by the inner Membrane of the
 Larynx.
   They differ in size in different people, have Mucous
 Follicles opening into them, and are found to be service-
 able in the modulation of the Voice.
   On the  anterior Surface ofthe Arytenoid Cartilages
 there it a small Depression filled by a Glandula- Body,
 which not only covers the fore-part of these Cartilages,
 but is continued over the posterior extremity of the Li-
 gaments of the Glottis.
  The  Arytenoid Glands are larger in some subjects than
 m others.  They were discovered, and are particularly
 described and delineated, by Morgagni.
  The  Ligaments which connect the Epiglottis to the
 Notch ofthe Thyroid Cartilage, and to the under side
ofthe Os Hyoides, and one which ties the Base of the
 Os Hyoides, from a triangular space, which  is also oc- .
 cupied by Cellular Substance and by Mucous Glands;
  The Cavity of the Larynx is lined by  a  Membrane
which is extremely irritable, and is every where perfo-
rated by the Mouths of small  Mucous Glands, for the
purpose of moistening it.
  The Larynx  has a number of Muscles; for its differ-
ent motions ; all oi which have been already described
  The  Arteries of the Larynx are the two superior La-
ryngeals^ which come from the External Carotids, and
the two inferior Laryngeals,  which are scntoff from the
Subclavian Arteries.
  The  Veins return to the External Jugulars.
  The  Nerves are chiefly the superior and inferior La-
 rfngeals, which are branches ot the Eighth Pair.
  The  Larynx serves the purpose of Respiration, forms 
81
and modulates the Voice, and is also useful in Deglu-
tition.
  It is the principal Organ of Voice ;—for, if a hole be
made in the Trachea, and the  passage ofthe Larynx
stopped, the Air escapes by that opening  without pro-
ducing Voice.
  Voice is  formed by the Air, in its passage  through
the Glottis,  acting upon the  Ligaments of the Glottis
and Cartilages of the Larynx  and Trachea, and thus
producing a Tremour ;—and  is different in different
persons, according to the Form and Structure of the
Larynx.
  The strength of Voice is  in proportion to the quafi-
tity of Air expired, and the narrowness of the Glottis.
  A Tone is acute  in proportion  to the tension of the
parts ofthe Larynx and Trachea in general, and of the
Ligaments ofthe Glottis in particular.
  A Tone is grave in proportion  to the reverse of the
above.
  Speech is performed chiefly by the different parts of
the Mouth, assisted by the Cavity of the Nose,—the
Larynx moving only in a small  degree.
  When the Air passes through the Larynx  without
producing a  Tremour it occasions a Whisper.
  When a person speaks during inspiration, the voice
is thereby very materially altered ;  and,  by practice,
may be made to appear as coming from  other places
than the Mouth of the speaker;  as is the case wifh
those who call themselves Ventriloquists.
            OF  Til K THORAX.

  The Thorax, or Breast, extends from the Neck to
tlie Diaphragm, and is uivided into External and  In-
ternal Parts.
        external parts  of the thorax.

  The External Parts ofthe Thorax, besides the com-
mon Integuments  ..ml Mamma:, are,
                      K  4 
                       82
  The Muscles, consisting of the Pectorales, Subelayjt,
and under end of the Platysma Myoides on each side,
which are situated anteriorly.
  The Serati Magni, which are placed laterally.
  The Trapzii, Latissimi Dorsi, and numerous other
Muscles on the Back, which are placed posteriorly.
  The Intercostales and Sterno-Costales, which are situ-
ated, the former between, and the latter on the inner
side ofthe Ribs.
  The Bones, consisting of Sternum,  Ribs,  and Dorsal
Vertebra.—All these  Parts, excepting  the Mamma:,
have been already described.
                    Mamm*.
  The Mamma are two Glandular Bodies, of a circu-
lar form, situated on the anterior,  and a little  towards
the lateral parts of the Thorax, adhering loosely by Cel-
lular Substance to the  Surface of the large Pectoral
Muscles.
  The term Mamma is peculiar to the Breasts of Wo-
men —In Men these parts are called Mammilla ;—and,
in the Brute-kind, Ubcra.
  In the Ape, and a few other animals, they are placed,
as in the Human Body, upon the Thorax ;—but, in the
generality of Qjiadrupeds, they are situated under the
Abdomen.
  The common number ofthe Mammae, in the Human
species, is well known to be two.—Bartholine, how-
ever, mentions the case of  a Woman, who  had  two
Mammae on the left side, and one on the right ;  and
another, where there were two on each side.
  Dr. Vaughan narrates the case of a Woman he has
exar.iined,  who has a  supernumerary  Nipple, at the
under side ofthe right Mamma, from which milk Row-
ed  when the central one was pressed, and vice versa-
  The Mammae vary in size in different Women,  and
in the same Women at different periods of life.
  In Girls, previous to the a0'e of Puberty, tliey are re-
markably small.
  About the age of fourteen, at which time  the Menses,
in this climate, most commonly begin to appear, they
evolve and become prominent.
  During Gestation they increase in  size, and soon af-
 ter Delivery they arise at their greatest extent. 
83
  After the age of forty-five, or from that to fifty,—the
period when the  Menses  generally disappear, they de-
crease in size, and become soft, pendulous, and flaccid.
  Under the Skin, there is a large quantity of Fat which
constitutes a considerable  portion of the bulk of the
Mamma, and defends the  Glandular Part, and is not
found to pass into, or communicate with, the Lactifer-
ous Ducts.
  The Glandular Part ofthe Mamma is of a whitish co
lour of the Conglomerate kind, and therefore irregular
in its Substance.
  It is composed of a number of smaller  Masses or
Glands, which are also separated by Fat; and these a-
gain are divided into still smaller  parts, in which the
Milk is originally secreted or formed.
  Near the'centre of the Mamma, is the Papilla or Kip-
pic, which is of a Cylindrical form, and of a redder co-
lour than the rest ofthe Skin of tlie Breast.
  It is of different  sizes in different ages and constitu-
tions, and is always larger in the time of Gestation, or
of Nursing.
  It is capable of distention from titillation, or when
influenced by the passions ofthe Mind.
  It is composed  of  a tough  Cellular or Ligamentous
Substance, which incloses the  Lactiferous  Tubes, and
which is so elastic, that after the part is drawn out or
distended, it readily  recovers its former dimension,
when the cause of distention has ceased to act.
  Upon the Apex ol the Nipple, the Orifices of the Lac-
tiferous Ducts appear and are of the same number with
those which enter its Base.
  Around the Nipple, there is a circle  or disk, called
Areola—of a different colour from the rest ofthe Skin
ofthe Breast.
   This Disk, however, varies  in colour  at different
times of life, being florid in young Girls, of a pale brown
in Women a little more advanced in life, and in old age,
of a livid and dull oolour.
   During Pregnancy, it is of a darker colour than  at
other times, in  consequence of a change which takes
place in the corpus Mucosum which forms it.
   Under the Skin of the Areola, there are numerous
  Sebaceous Glands, w Fallides, the  Orifices of which div 
84
charge an oily Mucous, to defend the Nipple and Areo-
la around it.
  The Arteries of the Mamma are partly from the In-
ternal, and partly from the External Mammaries or
Thoracics, the former of which  are sent off from the
S ubclavian, and the latter from the Axillary Artery,—
the Branches entering  the Mamma at many different
places.
  The Veins accompany the Arteries) and are distin-
guished by the same names.
  The Absorbents  of the  Mamma are also numerous,
the greater part of which pass through the Axillary
Glands, others penetrate the Interstices of the  Ribs,
near the Sternum, and enter the Glands which belong
to the Internal Mammary Vessels.
  The Nerves are chiefly from the Axillary Plexus, a
few Branches being also sent off from the Intercostals.
  From  the  extremities of the  Arteries in the Sub-
stance of the Mamma, numberless 'Tubes arise, called
Ductus or Tubili Lactiferi, which gradually  unite into
Trunks, and run in a radiated manner towards the root
ofthe Nipple.
  They become greatly enlarged  in the time of Sucking,
and serve as Reservoirs  in which the Milk is contain-
ed.
  The Lactiferous Ducts arc accompanied, in the Sub-
stance ofthe Mamma, by a tough white elastic Substance,
which follows them to the Nipple.
   At the root of the Nipple, they become contracted,
and are there from  Twelve to Eighteen in number.
  Either from the want of uniformity, however, with
respect  to their number in different subjects, or from
the difficulty of perceiving them, they have been vari-
ously estimated by different authors.
   Near the root ofthe Nipple, they have been supposed
by Qr. Meckel, to form a circle of communication ;—
but this has been ascribed by still later Anatomists, to
a laceration  of Vessels  ; and" numerous  preparations
and experiments,—particularly that of throwing in an
injection at one Duct, and finding that it fills one part
only  of the  Mamma,  without returning by any other
 Duct,—seem sufficiently to indicate, that there is no
 sur-h ojpculax communication. 
-85
  In the Substance ofthe Nipple, the Laciferous Tubes
arc at a little distance from each other, and arc coiled
up in such a manner, that the spontaneous flow ofthe
Milk is prevented, unless it be accumulated in a larger
quantity.
  But when the Nipple is drawn out and extended,—
as by the application ofthe Child's Mouth,—the Ducts
become straight and parallel to each other, so as to al-
low an uninterrupted flow ofthe Milk.
  After the action of Sucking, the Nipple, and of con-
sequence its Ducts, immediately recover their former
situation.
  Sometimes  one or  more of the Lactiferous Ducts
terminate upon the Surface ofthe Areola, from which,
Morgacni supposed that the Glands there were ofthe
Lactiferous kind.
  In Children  of both sexes, the  Mammae are merely
Cutaneous Tubercles, and at the time of birth contain
a Milky-like Fluid, which can be, readily squeezed out.
  This Fluid commonly  disappears a short time after
Birth ;—but there are  various examples  on  record,
where Milk has been  brought to  the Breasts, both of
young Girls and old Women, by the frequent applica-
tion of a Child to the Nipples, and where there was no
cause for suspicion of Impregnation being present.—
Nor are instances a wanting of Milk being brought to
the Mammillae of Men, by the same application.
  The Mammae add much to  the  ornament of the per-
son,  but serve  in particular for furnishing nourishment
to the Child, which is conveyed to it through the  me-
dium ofthe Nipple.
  The Secretion begins soon after Delivery,  and con-
tinues to  flow for many months,  and even  for some'
years, if the Woman suckle her  Child ; and the more
frequently the Milk is  extracted, the  greater is  the
quantity received in a given time.
  The operation of Sucking depends  upon the princi-
ples ofthe Air-pump.—The child  embraces the Nipple
closely  with its Lips,  whiOt prevents the external  A','
from entering, draws the Ducts to a straight line,  ami
prepares a space for the  Milk, which is forced from the
Breast by the pressure ofthe Atmosphere, and flows'i > 
86
 the Mouth in the manner a Fluid follows the Pisternof
 a common Pump or Syringe.

        INTERNAL FARTS Of THE THORAX.

  The Mammae and Muscles, covering the fore and la-
 teral parts of the Thorax,  being turned aside, and the
 Ribs afterwards cut from the Sternum and turned back,
 the Internal Parts of the Thorax are brought into view.
  They consist pf the Pleura, which lines the Thorax ;
 the Mediastinum, which divides it into right and left
 Cavities, and contains several Vessels,  Nerves, &c. be-
 tween its Layers ;—the Pericardium and Heart, which
 occupy the middle,—and  the  Lungs,  which surround
 the Heart, and fill the greater part of the Thorax.

                     The Pleura.
  The Pleura is a Membrane of considerable strength,
 which lines the inner side  of the  Thoi'ax, and covers^ ^
 the most of its  contents.
  Its External  Surface  is Cellular, and adheres closely ^
 to the parts which surround it.
  Its Internal  Surface  is  smooth  and polished, being
 moistened by a Serous  Fluid,  which exudes  from its
 Arteries.
  It is divided  into two lateral Sacs or Pleura, the form
 of which corresponds exactly with that of the surround-
 ing Bones of the Thorax.
  The Pleurae  adhere to the Periosteum of the Ribs,
 line  the Intercostal  and Sterno Costal  Muscles,  the
 Sternum, and Dorsal Vertebrae, and cover the Pericar-
 dium, Lungs, and Lateral or Fleshy parts of the Dia«
 phragm.
  Behind the Sternum,  the Pleurae are contiguous to
 each  other, and form a Partition called Mediastinum,', jjg
 which extends between the Sternum and Vertebrae, but
 is intercepted by,the Heart and Root ofthe Lungs, and
 divides  the  Thorax into two distinct Cavities, which
 have no communication with each other.
  The Arteries ofthe Pleura are from those of the ad-
jacent parts, viz. from  the Intercostal,  Mammaries,
 Diaphragmatics,  Bronchical, and Esophageal.
  The Veins, which return the  Blood, accompany the
 Arteries* and are distinguished  by  the same names. 
87
  The Nerves are from the Intercostals and Diaphrag-
matics, but too  small to be traced without difficulty ;
and the Membrane itself is not observed to possess much
sensibility in the sound uninflamed state.
  The Pleura serves to render the inside ofthe Thorax
smooth, for the easy motion  of the contiguous parts,
to divide  it into  Cavities, and to  strengthen the con-
taining and contained parts ofthe Thorax.

                   Mediastinum.
  The Mediastinum, so named from its situation in the
middle of the Thorax,  is formed by a reflection ofthe
Pleura, and is of course double.—It contains between
its  Layers a considerable quantity of  Cellular Sub-
stance, by which they  are united.
  It is divided into Anterior and Posterior Mediastinum,
the former of which is situated at the fore, and the lat-
ter at the back-part ofthe Thorax.
  The Anterior Mediastinum is connected before, to the
Sternum $ and behind, to the Pericardium  and large
Vessels ofthe Heart.
  The two Layers of the Anterior Mediastinum are
closely applied to each other, excepting at the upper-
part of the Thorax, where they are separated by the
remains of the Thymus Gland.
  At the upper-part of the Thorax, it lies  exactly be-
hind the middle of the  Sternum ;  but in its descent, it
inclines gradually to the left edge of that Bone.
  In consequence of its  obliquity, a pointed instrument,
pushed through the centre ofthe Sternum, is generally
found to pass  into the right Cavity of the Thorax.
  Frequent deviations, however, from this general rule,
have been  met  with—In particular, Ludtaud and
Sabatibr relate several instances where the Anterior
Mediastinum  was found  to descend along the middle
of the Sternum ; and others, though rare, where it de-
scended even to the right side of this Bone.
  The Posterior Mediastinum reaches from the root of
the  Lungs and back-part ofthe Heart, to the Dorsal
Vertebrae.
  Between the Layers of the Posterior Mediastinum, a
triangular  space is  formed, in which are situated the
under end of the Trachea, the Esophagus, and Aorta 
88
Descendens, the Vena Azygos, and Thoracic Ducti
with the Eighth Pair of Nerves.
  The Blood-vessels of the Mediastinum are from those
of the neighbouring  parts .-—The  Anterior Mediasti-
num is supplied by Branches from the Subclavian,  In-
ternal Mammaries, and Diaphragmatics,—and the Pos-
terior Mediastinum, by Branches from the Intercostals
and Esophageals.
  The Veins accompany the Arteries, and hjive the sanae
names.
  The Mediastinum divides the Thorax into two Cavi-
ties, supports its general  Contents, hinders one Lung
from pressing upon the other, when the person lies on
his side, and prevents Fluids,—which, in consequence
of accident or disease, may be contained in the Cavity
of the Thorax,—from passing from one side to the other.

                   Pericardium.
  The Pericardium, Sac, or Capsule of the Heart, is one
of the strongest Membrane  of the Body,  and  its size
such as to be  properly adapted to that of the Heart,
which it contains.
  It is formed of two Layers, the External of which is a
continuation of the Anterior Mediastinum, which af-
terwards passes to the Lungs and lateral parts  of the
Diaphragm.
  The Internal Layer is smooth,  tendinous like, and
polished on its inner Surface, and is stronger than the
other.
  It adheres so firmly to the Tendinous part of the Di-
aphragm, as not to be separated from it without much
difficulty.
  The Pericardium extends a considerable way beyond
the Base of the Heart,  and  includes the large Bood-
vessels, as far as the roots of their first principal Bran-
ches, in consequence of which it  forms  several angles,
which have been termed  Cornua of the Pericardium.
  While the External Layer is  reflected to  cover the
parts which surround it, the inner one is also reflated,
first over the roots ofthe  large Blood-vessels, and then
over the Heart, to form its proper covering, in the same
manner the Tunica Conjunctiva is reflected from the
Eye-lids to cover the fore-part of the Eye. 
                        89
  From the ends  of the  Extreme Arterfes,  upon its
Surface, a Fluid, called Liquor Pericardii, it discharged,
by which it is lubricated, and the effects of Friction
diminished.
  The Liquor Pericardii is commonly found after death,
in the quantity of a few drachms,  though  not unfre-
quently of one  or two ounces.
  Its colour is redder in a young subject, than in a per-
son advanced in life, in whom it becomes paler, or more
of a straw colour.
  The Arteries ofthe fore-part ofthe Pericardinum are
from the Internal Mammaries and Diaphragmitics; those
of its fore-part from the Bronchial and Esophageal.
  The Veins correspond with the Arteries,  and have the
same  name.
  The Use of the Pericardinum is, to preserve the Heart
iu situ, to  defend it from being injured by the  parts
which surround it, and to restrain its inordinate mo-
tions.
              OF  THE HEART.


  The Heart is a hollow Muscle, divided into different
 Cavities, and inclosed in the Pericardium.
  It is situate in the Cavity ofthe  Thorax, behind the
 Sternum, between the Right and Left Lungs.
  It is of a Conical figure, flattened at one side, and is
 divided into Base, Body, and Apex, with a  Superior and
 Inferior Surface, and a Right and Left Margin.
  The Base is placed backwards next the Spine, while
the Body and Apex  are turned forwards, and obliquely
 over to the left side.
  In Quadrupeds, the Heart is placed upon a line with
the Sternum, the point only touching the Diaphragm :  In
the Human Body, the Apex, or point ofthe Heart, is but
little lower than  the Base, and  projects between the
two lobes of the left Lung, behind the Cartilages of the
 Fifth and Sixth True Ribs of the left Side, or a little
 below the left Nipple, where the Pulsation may be felt*, 
90
1 he situation, however, varies a little, according to the
position ofthe Body, and state of Respiration.
  Though this be the common situation of the Heart,
a few rare and singular instances have occured, where
it has been fotmd to occupy the right side ofthe Tho-
rax ;  and a displacement has sometimes  happened, in
consequence of different  kinds of tumours in the left
side ofthe Thorax.
  The Superior or Anterior Surface of the Heart is con-
vex, and is opposed to the Posterior  Surface of tlje
Stoinum, the anterior edges ofthe Lungs intervening. ?
  The Inferior or Posterior Surface is flat,  and rests up*
on the Tendon of the  Diaphragm which supports it;
the Heart is not much affected, however, by the mo-
tious of that Muscle in time of Respiration, its Tendon
moving only in a small degree.                        I
  The right side of the Body of the Heart is sharp, and   I
is called Margo Acutus.                             ■ ^k
  The left side ofthe Body ofthe Heart is round, and fl
is termed Margo Obtusus'.                            -^1
  The Base is formed of a right and left Auricle, and )1
the Body of a right and left Ventricle.
  When the Heart is distended, the right Auricle, and » I
part ofthe corresponding Ventricle, occupy  the right,
and the rest of the Heart the left Cavity  ofthe  Tho-   '
rax.                                                 '
  The Heart  is connected above and  behind to the up.
per and back-part ofthe Thorax, through  the medium
of the great Vessels which go into, or pass out from it.
  The other parts of the Heart are free,  being merely
contiguous to the inside ofthe Pericardium.
  The External Surface ofthe Heart is covered with a
thin smooth Membranous Coat, which is a reflection of
the inner Layer of the Pericardium, and  which  gives
additional strength to its Fleshy Fibres.
  Between the Coat and Substance of the Heart, there
is commonly a considerable quantity of Fat, which lu-
bricates it, and facilitates its motions.
  The Substance of the Heart consists of  Muscular
Fibres, firm and more  closely connected  than the ge-   •'
nerality of Fibres of Muscles in other parts of the Body.   $
  The Fibres run in different directions, longitudinal   '
and trans/erse, hut most of them oblique,. 
                         91
   Many of them run over the Point ofthe Heart from
one Surface to the other, and the whole so much twisted
and folded, and so variously intermixed, as to be dif-
ficult to be unravelled or described :—In general, how-
ever,  their course is such as to lessen the Cavities ofthe
Heart in all their dimensions.
   The Cavities of the  Heart are lined with a Membrane
extremely thin, but dense and strong, to defend them
against the pressure ofthe Blood.
   The  Heart is formed of an anterior or right, and a
posterior or left side, or of a right and left Heart, joined
together by a Partition,  which  prevents  the two sides
from  having any direct communication with each other.
The terms Kight and Left, however, are more applica-
ble to the Heart ofthe Quadruped, and those of Ante-
rior and Posterior to the Human Heart.
   Each side of the  Heart is furnished  with  a set of
Veins, with an Auricle, a Ventricle, and an Artery, and al-
so with two sets of Valves,—one between the  Auricle
and Ventricle, the other between the  Ventricle and
Artery,
   At the right side of the Heart are two Veins, called
from  their large size Vena Cava, the one Superior, the
other Inferior.
   The Superior Vena  Cava, called also Vena Cava De-
scenders, returns the Blood from the upper parts of the
Body ;  and  the Inferior Vena Cava, termed  likewise
Ascendens, return it  from the  lower parts ; and both
terminate in the  right  Auricle.  It is prevented from
returning by the fulness of the Veins, and by the pres.
sure of the Blond a tergo.
   The Auricle is situated upon the  right, and partly
upon  the back-part ofthe Heart, and is divided into the
right  Sinus Venosus and proper Auricle-
   The Sinus Venosus  is formed by the Union of the two
Venae Cavae, which swell out towards the anterior and
left side.  It is notched at its anterior edge, as a Mus-
cular  Bag of considerable strength, and is uniform and
smooth, both upon its outer and inner Surface.
   At  the upper and left  side of the Sinus,  is the pro
jectionor Appendix, termed Proper Auricle, from its sup-
posed resemblance to the Ear of a Quadruped :—It is
formed by a blind Sac,  which is sen\i!-»d and i-io^hed
      tor..  11.            k 
92
on its posterior edge, and convex  or rounded on the
other, and terminates obliquely in an obtuse point.
  The Sinus and proper Auricle form one common Ca-
vity, have no Valve between them, and are  therefore
filied and emptied at the same time.
  Where the two Cavities meet in the Hearts of Quad-
rupeds,  there is a projection seen in the Sinus Veno-
sus, called Tuberculum Lowzri, which is supposed to
prevent  the Blood of the one Cava  from rushing upon
that of the other, and to direct it into the Auricle.
  At the meeting ofthe two Cavae in the Human Heart,
an angle is formed, which also has frequently got the
name of Tuberculum Loweri :—That substance, how-
ever,  is  peculiar to the Hearts of Brute-Animals.
  Under this Angle, or joining of the Venae Cavae, there
is the Vestige ofthe Foramen Ovale, which in the Foe- '
tus, forms a communication between the right and left
Auricles ; but, in the Adult, is  filled up by its Mem-
brane, and forms the Fossa Ovalis-
  The Fossa  Ovalis has thick and strong sides, called
Column* Foraminis Ovalis, isthmus Vieussenii, or An-
nulus  Foss* Ovalis.
  At  the left side of the Mouth of the Inferior Cava,
where it joins the Sinus, is the  Valve of Eustachils.
  It is in form of a Crescent, with the Convex  edge
fixed  to the union of the Sinus and Cava, and the con-
cave  edge turned obliquely upwards, reaching about
half-way over the Mouth of the Cava.—Its size and ap-
pearance, however, vary much in different Subjects.
  Its posterior Cornu is continued with the left side of ^
the Isthmus of the Foramen Ovale ; the other end van-
ishes in the opposite side of the Sinus.               *
  It is equally distinct in the Adult as in the  Foetus; i
but in the former it is frequently found reticulated, or
Cribriform, which appearance is seldom, though some-
times, met with in the latter.                        '
  In tlie Adult,  it is supposed to prevent the Blood of j
the Auricle from passing into the  Inferior  Cava; and
in the Foetus, to direct the Blood of  the Inferior Cava
to the Foramen Ovale.
  Upon the left  side ofthe Valve of Ecstaciiius, in
the under part of the  Auricle, is the Orifice or Termi-
nation of the great Coronary Vein ofthe Heart. 
93-
  Over the Orifice of this Vein, there jis a Semilunar
Valve, to prevent the Blood in the  Auricle from pass-
ing into the Vein.
  The inner side ofthe proper  Auricle is readily dis-
tinguished from the  Sinus, by having a number of Co -
lumn* Came*, or Fleshy Pillars in it, which, from their
supposed resemblance to the  Teeth of a Comb, some-
times obtain the name of Musculi Auricul* Pectinati.
  The Musculi Pectinati have smaller Columns  run-
ning in different directions, giving  the whole a  reticu-
lated appearance.
  Between the  Columns Carneae, are Depressions or
Furrows, in which the sides of the Auricle are thin, and
semi-transparent, being chiefly formed by the outer and
inner Membrane of the Auricle.
  At the under and left side ofthe Sinus Venosus, and
opposite to a  Groove, situated externally  between  the
Auricle and Ventricle, there  is a Hole, above an  inch
in diameter,  whicli opens into the upper and right part
of the corresponding Ventricle.
  The right Auricle  receives  the Blood from the Venae
Carvx and Coronary  Veins, and, by its Muscular con-
traction, discharges it into the corresponding Ventricle,
out of which it is prevented from returning by a Valve,
called Tricuspid, placed within the  Ventricle
  The Right or Plumonary Ventricle, is situated on the
fore-side of tlie  Heart, is of  a triangular form,  and
much thicker and stronger than the corresponding Au-
ricle.
  It has many strong Eminences, Columns, Lacertuli,
or Cords, called Column* Cane*.
  The Column* run in different  directions, but the
strongest of them longitudinally,  and are of  various
sizes, forming so many distinct Muscles, which are ex-
tremely compact in their structure,  and compose a
beautiful,  intricate,  and irregular  Nef-work.
  In general, they adhere through their whole length
to each other,  or  to the sides of the Ventricle ; but
many of them are loose in their middle, and many be
raised by a probe put under them.
  They assist the Ventricle in its Systole or contraction,
and prevent it from being overstretched in its Dyastole 
94
or  dilatation, and  agitate tlie Blood in its  passage
throughthe Ventricle.
  They are supposed to bring the opposite sides of the
Ventricle completely together, during its contraction.
  Between the Columnae are many deep Grooves,  Pits,
or Foveae, into all of which the Blood readily enters.
  Around the Passage,  between the  Auricle and  Ven-
tricle, there is a  Tendinous Margin  or Ring, from the
whole edge of which a  circular Membrane is sent off,
called  Valvula  Tricuspis,  or  Triglochin, from its  hav-
ing three principal points  or divisions.
  From the edge of the Tricuspid Valve, many small
round Tendinous Cords are sent off, of unequal size.
  The Chord* Tendine* descends obliquely within the
Ventricle,  in the same direction  with the Valve  from
which they arise.
  They are fixed to the  extremities of a few strong  j
Papillae or Columnae, Carneae,  which are joined by their  i
other extremities to the corresponding sides of the Ven*  '
tricle.
  The Tricuspid Valve prevents the reflux of the Blood   j
to the Auricle, during the  contraction ofthe Ventricle.   *.
  The Tendons allow the Valve to be pushed  back by
the Blood,  until a Septum or  Partition is formed  by it
at the Mouth of the Ventricle, during the contraction '  !'
ofthe latter.—The Papillae, by their contraction, pre-
vent the Valve  from going into the Auricle.
  The Valve is opened and pressed back by  the Blood
in its passage from the Auricle to the Ventricle.
  The upper and left side of the Ventricle becomes
bmooth  and uniform, and leads to  a  large opening, a-
bout an  inch in diameter, which  is the Mouth ofthe
Pulmonary Artery.
  The right  Ventricle, by its dilatation, receives the
Blood from the  Aurisle, and  sends it by a strong and
sudden  convulsive contraction, to the Pulmonary Artery,
from whence it  is prevented from returning, by three    '
Valves placed in the Mouth of the  Artery.
  The Valves at the Mouth of the Pulmonary Artery
are called Valvula Semilunaries, or Sigmoide*, from the
resemblance of their edges to those of a Crescent.—
Two of them are placed in the fore, and one in the back
part ofthe  Artery. 
95
   Each of them forms a small Sac, one edge of which
 adheres to a third part ofthe circumference ofthe inside
 ofthe Artery ; the other edge is loose in the Cavity of
 that Vessel, and is somewhat thicker and stronger than
 the rest ofthe Valve,—the thickened edges serving as
 Ligaments to it.
   The loose edge has a general Curve, divided into two
 smaller ones, which meet in & point in the middle.
   The Valves are chiefly formed of a doubling or ex-
 tension ofthe inner coat ofthe Artery.
   In the  middle point or loose edge of each of the
 Valves, there is a small hard  triangular Granula, of a
 somewhat redder colour than the rest of the Valve, cal-
 led, from  its reputed discoveries, Corpusculum Acran-
 tii, or Corpusculum Morgagni ; or from its resem-
 blance in  shape to the Sesamum  seed, Corpusculum
 Sesamoideum.
   The Corpuscles complete the Valves at the centre of
 the Artery,  and enable them to make a stronger resis-
 tance against the Blood, while the Artery is in action.
   The Semilunar Valves are concave towards the Ar-
 tery,  convex towards the Ventricle,  and when  shut,
 their loose edges are opposed to each other, so  as to
 enable them to form a complete Partition between the
 Ventricle and Artery.
   Opposite to the Semilunar Valves, the Artery bulges
 out, and forms three projections, which have correspond-
 ing Pitts or  Depressions  within, and  are called, from
 their discoverer. Sinus Valsalvae,
   The Sinuses of Valsalva are of the  same  nature
 with those Dilatations which are found in the Veins
 and Lymphatics, between their sides and Valves ; and,
 like them, are partly formed by  the  pressure of the
 Fluids upon  the sides ofthe Vessels.
  The Pulmonary Artery receives  the Blood from the
right Ventricle,  and by its contractile power, assists
the Ventricle in driving it through the Lungs.
   The Semilunar Valves, pressed back by the Blood in
the Artery, prevent its return into the Ventricle.
   The Valves are opened again by being driven towards
 the sides of  the Artery by the current ofthe Blood, up-
on the next contraction or stroke ofthe Ventricle.
F 2 
96
   The Plumonary Artery passes behind tlie Sternum,
and separates into right and  left Branches, which go to
the corresponding parts ofthe Lungs.
  The two Branches of the Pulmonary Artery, like
those of the  Arteries of the Viscera in other parts of
the large Cavities,  suddenly divide  into still smaller
Branches.
  From the extreme Arteries of the Lungs, correspon-
ding Veins arise, and are merely the continuation  or
reflection of  the Arteries, without any intermediate
Cells or Dilatations.
  The Pulmonary Veins, in the Substance ofthe Lungs,
gradually unite, and formybur principal Trunks, which
terminate in,  and carry the Blood to the left Auricle.
  Of the Pulminary Veins, two come from the right,  *
and two from  the left lung, and terminate in the corres-
ponding sides ofthe left Auricle.
  The left Auricle is considerably thicker and stronger
than the right, and, like it, is divided into Sinus Veno-
sus and proper Auricle, which form one common Ca-
vity without the intervention of any Valve.
  The left Sinus Venosus,  called also  Sinus Pulmonalis,
is turned towards the Spine, is more of a cubic form
than the right one ;  but resembles it in the uniformity
and smoothness of its outer and inner Surface.
  From the fore and left part of the  Sinus, the  Proper
Auricle projects, and forms a distinct flat Appendix,  or
Bag,  with different  Cervatures or Indentations upon its
edges.
  The inner  part of the  Proper Auricle is longer, but
narrower than that on the right side ; like it, however,
is formed of  Columnae, Carneae with Furrows between
them.
  The Proper Auricle is somewhat less capacious than
that on the right side ; but the Sinus is as much  larger
as to render the two common Cavities of the right and
left Auricles  nearly  equal.
  The two Auricles have a Fleshy Septum between them,
in which, as has been  already mentioned, there is the
Foramen Ovale  in the Foetus;—but in the Adult the
Partition is generally perfect.
  From the under part of the Sinus Venosus, a Passage
leads down to the Cavity of the Left Ventricle,  and is 
97
opposite to a Groove seen externally between the Au-
ricle and Ventricle, similar to that on the right side.
  The Left Auricle receives the Blood from  the  Pul-
monary  Veins,  and by its Muscular contraction, drives
it into the Left Ventricle, from which it is prevented
from returning by a Valve in the Ventricle, called Mi-
tralis.
  The Left Ventricle is situated  in the posterior and
left part of the  Heart
  Its sides are about three times thicker and stronger
than  those of the Right Ventricle, being in proportion
to the force  required to propel the Blood of the most
remote parts to the Body.
  It is narrower and rounder, but considerably longer,
both on its External Surface and in its Internal  Cavity,
than the Right  Ventricle, and generally descends some-
way below the  other, and forms the Apex cordis,  or
Point ofthe Heart.
  The Cavity is commonly described as being less than
that ofthe Right Ventricle ;—but the apparent differ-
ence, which takes place after death, is  accounted for
with  seeming propriety by  some Authors,—from the
left Ventricle being then for the most part found empt)',
and the Right one full, and from the greater degree of
contractility in the former.
  That the capacity of the Cavity ofthe right and left
Sides of the Heart, is more  nearly equal during life
than after death, or that it is generally supposed to be,
is evident  from the appearance of the Heart of the
Human and also of the Brute kind, and from  injections
into the two sides ofthe Heart where the force applied
is in proportion to the relative strength of each side.
  The inner Surface ofthe Left Ventricle has the same
general appearance with the Ventricle ofthe right side,
and only differs from it in having its Columnae  Carneae
larger, firmer and stronger.
   In the Passage of communication between  the Auri-
cle and Ventricle, there is  a Ring, from which a  Cir-
cular valve goes  off, with  all its apparatus similar to
that between the right Auracle and Ventricle, and dif-
fering in no respect from it in structure and  use, ex-
cepting in being stronger, and  being divided into two
principal portions only. 
                        98

   This Valve has been supposed to bear some resem-
 blance to a Bishop's Mitre, from which it has been cal-
 led Vavula Mitralis.
   One ofthe portions of this Valve is larger than the
 other, lies over the Mouth ofthe Aorta, and is supposed
 to cover it while the Ventricle is a filling.
   The Valvula Mitralis prevents the reflux ofthe Blood
 during the contraction ofthe Ventricle.
   After the contraction is  over, the Valve returns to
 its former situation by the impulse of a fresh current
 of Blood from the Auricle.
   Between the Right and Left Ventricle, thereis a thick
 strong impervious Partition, which forms a share ofthe
 general Septum Cordis, and is composed partly by th^
 wall ofthe right, but chiefly by that of the let'-. ventricle.    ■
 the right being united to the left, almos  in the form ol   t
 an Appendix.
  The Partition prevents any direct communication be    |ij
 tween the two Ventricles.                             .a
   Opposite to the outer edge ofthe Septum, both upon   1
 the upper and under Surfaces of the Heart, there is a   I
 Groove in which some  of the principal Trunks of the
 Coronary Vessels are situated.
   At the fore and  right  side of the Valvula  Mitralis,
 and behind  the beginning  of the  Pulmonary Artery,
 there is a round Opening, which is the Mouth  of the   {
 Aorta,  and which is nearly of the same size with that
 ofthe Pulmonary Artery.                              i
  Under this opening, the Surface ofthe Ventricle be-
 comes smooth,  and equal, having none of the Columnae
 Carnejc which are seen on the other parts of its Cavity.
  The Left Ventricle receives the Blood sent to it from
 the Auricle, and by a contraction similar to, but much
 stronger than that ofthe  Right Ventricle, propels it to
 the Aorta.
  At the Mouth of the Aorta, there  are three Semilu-   J
 narvalves, with their Corfiuscula Aurantii, perfectly   J
 similar to those of the  Pulmonary Artery ;—but a lit-   ■
tie stronger.                                          1
  On the outside.of the Semilunar Valves, are the Sin-    j
w.vcjf of Valsalva, like those of the Pulmonary Artery, .   '
 but a little more prominent.
  'The Semilunar Valves arc pressed back by the Blond,
 and prevent its reflux during the contraction  of the 
99
  Aorta:—They are returned towards the sides of tlie
  Aorta, in the same manner, and from the same cause,
  as in the Pulmonary Artery.
    The Aorta passes upwards from  the top of the Left
  ventricle, and is situated first behind, and then on the
  right side ofthe Pulmonary Artery, and between it and
  the Superior Cava.
    It bears nearly the same proportion in thickness and
  strength to the  Pulmonary Artery, which tlie sides of
  the Left ventricle do to those ofthe Right.
    When the Aorta is about to send off the  first of its
  large Branches, at the top of the Thorax, it is of great
  size, and is sometimes called the Large Sinus of Val-
  salva.
   The Aorta receives the Blood from the left ventricle,
  and by its Muscular contraction re-acts upon  it, and
  assists the ventricle in sending it by numberless Bran-
  ches through  the different parts of  the Body, from
  whence it is returned by the veins  to the Right Auri-
 cle.
   Besides the Blood-vessels already taken  notice  of,
 and which are common  to the Heart and the rest  of
 the Body, the Heart is furnished with vessels peculiar
 to itself, termed Coronary, form a Corona which they
 form upon its surface.
   The Coronary vessels consist of two Arteries and one
 principal vein.
   The Coronary Arteries arise from the Sinuses,  at the
 Mouth ofthe Aorta,  opposite to two of the Semilunar
 valves.
   One runs in  a Groove between the  Right Auricle and
 ventricles,  and supplies chiefly the right side of the
 Heart.
  The other passes partly between  the  Left Auricle
 and Ventricle,  and partly in the Groove between the
ventricles,  on  the fore-side  of  the  Heart,—supplying
the left side of the  Heart, and communicating with
the branches ofthe other Artery on its upper and un-
der surfaces.
  The Coronary Arteries are entirely dispersed upon
the substance  ofthe  Heart,  and upon  the roots of the
great vessels,  forming upon these some of the minute
Branches, termed vasa vusorum.
                        ¥ 4 
100
  The Coronary Arteries, from their situation opposite
to the valves, have  been supposed to be filled at a dif-
ferent time from that ofthe rest ofthe Arterious Sys-
tern;—but from experiment, it seems now sufficiently
evident, that the Coronary vessels have their pulsation
at the same instant  with the other Arteries.
  The  Coronary veins  return the Blood from their
corresponding  Arteries :—The greater part of them
join into a Trunk, called the Great Coronary vein,  which
after making a turn from the K"'t side, and running be-
tween the Left Auricle  and Ventricle, terminates in
the under part ofthe Right Auricle, where it is cover-
ed by its  Semilunar Valve.
  Other  Coronary  Veins, much  smaller  than the for-
mer, terminate in different parts ofthe  right side of
the Heart.
  The Absorbents of the Heart go to the neighbouring
 Lymphatic Glands.
  The  Nerves are  from the great Sympathetica and
 Eighth Pair.
   With respect to  the Circulation in general:—The
 Veins return the Blood from  all  the  different parts of
 the Body by a slow and equal motion, and without pul-
 sation,  to the Auricles, whicli, on account of the quan-
 tity and stimulating quality ofthe Blood, contract sud-
 denly and at  the same time, and send it to the Ventri-
 cle.
   The  ventricles, from the same  cause which  stimu-
 lates the Auricles, and from the stroke they receive
 from them, contract convulsively, with a force propor-
 tioned  to the thickness of their sides, and send  the
 Blood  to the Arteries ; and, during  their contraction,
 they are thrown by the dilatating Auricles  against the
 Ribs, where the stroke occasioned by the Pulse of the
 Heart may be felt.
   The Arteries, by their contractile  power and elasti-
 city, send  the Blood  suddenly to the veins, through
 which, by  the united  force ofthe ventricles and Arte-
 ries, and likewise, as  is  supposed by some, by a con-
 tractile power of the veins and pressure of the surround-
 ing parts, it is driven again to the Auricles.
   In its course the  Blood perforins a double Circulation,
 —one called the Lesser or that thiough the Lungs ;— 
101
 the other called the Greater, or that through the Body.
   In the former it passes from the Right ventricle to
 the Lungs,  and returns to the Left Auricle.—In the
 latter, it goes from the left ventricle to the different
 parts ofthe Body, and returns to the Right Auricle.
   During this Circulation, the Auricles  and Arteries,
 and the Ventricles and Veins, act in concert, contract-
 ing and dilating at the same time.
   Use of the Heart.—The  Heart is the  centre of the
 Vascular System, and principal agent in the Circula-
 tion ofthe Blood.
   The right side of the  Heart receives  the  Blood,
 which is contaminated in passing through the Body, and
 sends it to the Lungs, where it is purified through the
 medium  ofthe Air.
   From the Lungs, the Blood, now purified, is retur-
 ned to the  left side of the  Heart to be circulated
 through all the other parts of the  Body, thereby im-
 parting  Nourishment,  Growth, and  Strength to the
 general  System ; being found also to be  the source of
 Sensibility,  Irritability,  and  Motion, and likewise  of
the Animal  Heat.
              OF THE LUNGS.

  The Lungs axe two soft spongy bodies, which occupy
by much the greater part of the Cavity ofthe Thorax.
  They completely fill the two bags ofthe Pleura, and
are every where in contact with the parts adjacent j
no air intervening between them and the Thorax.
  In figure, they  have been compared to that of the
Foot of an Ox, with the back-part turned forwards ;
or, their shape corresponds exactly with the inside of
the Thorax, being rounded next the Ribs.hollow towards
the Diaphragm, and irregularly flattened and depres-
sed next the Mediastinum and Heart.
  They are of a reddish or pink colour in Children, of
a light blue or greyish colour in Adults, and more of a
purple and lived colour in old age, at v. Licli period they 
102
are also observed to be tinged with black spots, proceed-
ing from a matter secreted in their substance.
  They are joined to the Neck, by the Trachea; to the
Spine, by the two Layers of the  Mediastinum, which
serve them as  Ligaments ;  and to the Heart  by the  .
Pulmonary vessels ;—the rest  of  them being free and
unconnected, unless an adhesion has taken place in con-
sequence of inflammation.
  They are divided into Right and  Left  Portions, or
Lungs, which  are separated from each other by the
Heart and Mediastinum, and which have no  communi-
cation, excepting through  the Medium of the Tra-
chea.
  Each ofthe Lungs is again  divided into large por-
tions called Lobes,  which facilitates their motion and
the dilatations of their Cells.
   Of these Lobes,  three belong  to  the  Right  Lung,  jj
corresponding with the larger  Bag of the  Pleura, and  ij
two to the left, between which  there is a Notch or Sinus '<-
occupied by the point of the Heart.
   Each of the Lobes is subdivided  into many smaller
parts, termed Lobules, which are of different sizes, and -
of an irregular angular form.
   The Lobules diminish in size, and degenerate at last
 into small  Vesicles  or  Cells, which constitute a large
 share of the Lungs, and which are merely visible to the
 naked Eye.                                         „
   The Cells of the  Lungs  are purely Membranous, of j
 an irregular figure, compressed and  closely connected,
 and have a free communication with each other.       ?
   Between the different Lobes, Lobules, and Cells,
 a large quantity of common Cellular Substance, desti-
 tute of Fat, is interposed, which unites and strengthens
 them, and allows the Blood-vessels to be minutely dis-
 persed over them.
   The Cells of the Lungs have no communication with
 this common Cellular Substance ; for when Air is blown
 into it, the Lobules are compressed ; but when the Air -
 is blown in through a Branch  of the Trachea, the Cells
 are again distended,  and the Lobules  recover their
 former dimensions.
   In the Pectus, the Cells are  empty and in a collapsed
 state :—but as r.oon ns Respiration begins, they become 
103
 distended, and continue so during life, and in every
 state of Respiration, and even in the recently dead body;
 but if an opening be made into the Cavity of the Tho-
 rax, whether in the living or dead body,—and the Air
 in this or in any other way  admitted, they immediately
 collapse by their own weight and elasticity, the pres-
 sure ofthe air being then  the same  on the outer sur-
 face ofthe Lungs, and the inner Surface'of the Tra-
 chea.
   The Lungs are covered by two coats, an External or
 Common, and an Internal or Proper one.
   The External or Common coat is a continuation or re-
 flection of the Pleura, is extremely thin, but dense, and,
 like the  other parts of the Pleura, is found to possess
 little Sensibility.  It forms a  general  covering to the
 Lungs, but does not enter between the different Lob-
 ules.
  The Internal or Proper coat adheres so firmly  to the
 former, as to appear to constitute part of its Substance.
 It not only covers the Lungs, but insinuates itself be-
 tween their Lobules, and is intimately connected with
 their  Cellular Substance.
  Besides the Cells, various kinds of Vessels, viz. the
 Air-vessels or Branches ofthe Trachea, Blood-vessels and
 Absorbents, together with small Branches of Nerves, en-
 ter  into the composition ofthe Lungs.

                     Trachea.
  The Trachea,  or Aspera Arteria, so  called  from the
 inequality of its  Surlace, and from its conveying Air,
 begins at tlie under part ofthe  Cricoid Cartilage, and
 descends in the fore-part ofthe Neck, between and be-
 hind the  Sterno-hyoid and Sterno-thyroid Muscles.
  From the Neck, it passes into the Thorax,  where it
 is sittiated between the Layers ofthe upper part of tlie
 posterior Mediastinum.
  Behind the Curvature ofthe  Aorta,  and opposite  to
 the third  Vertebra of the Thorax, the Trachea divides
 into two  Lateral Branches, termed  Bronchi, from the
 Greek, one of which goes to the Right, and the other,
which is the longer oi" the two, to the Left Lung.
  The Bronchi are  divided into Brandies, which  by
degrees become smaller, arfd ut  last terminate  in the 
                       104
Cells ofthe Lungs, which communicate so freely with
each other, that, upon introducing Air into any of these
Branches, a large portion  of the Lungs may be infla-
ted.
  The Trachea consists of Cartilaginous  Rings,  about
sixteen in number, which give  strength  and firmness
to it,  and preserves it constantly open for the transmit-
sion of Air.  They are incomplete  behind, where the
Trachea is  formed of a soft Fleshy Substance, which
yields to the Esophagus in the time of Deglutition.
  Each Cartilage forms a large segment of a circle,  a-
bout a line, or one-twelfth of an inch  in breadth, and
one-fourth of a line in thicknessj
  The Cartilages are situated horizontally, with their
edges opposed to each other, small spaces intervening
between  them.
  They are  united to each  other, by  a  Ligamentous
Substance, which is so elastic, that when the Lungs are
taken out of the Body, it draws the Cartilages closely
together.'
  At the upper end of the Trachea, two or three ofthe
Cartilages are frequently joined by an union of Sub-'
stance ; but below this, they are perfectly distinct from
each other.
  The beginnings ofthe Bronchi have the same kind of
Cartilages with the Trachea ; but after they enter the
Lungs, they are broken into two or three  pieces, which
go completely round the Bronchi, and are so connected
to each other,  as to keep the Passage open  and free
from  Compression.
  The Trachea has several coats entering into its com-
position, some for strengthening it, others  for giving
it a certain degree of motion, viz.
  A Cellular coat, which in the Thorax, is covered by the
Mediastium.
  An Elastic Ligamentous coat, which passes along the
Trachea and also upon the different  Branches in the
substance ofthe Lungs, adding much  to tlie elasticity
of these.
  A Muscular coat, placed between the Cartilages, and
in the back-part of the Trachea, and composed of cir-
cuhir  Fibres without, and Longitudinal Fibres within ; 
105
the former for straightening, the other for shortening
the general Passage.
  The Longitudinal Fibres are collected into bundles,
which are distinctly seen through the inner coat, and
may be traced considerably farther, in the substance of
the Lungs, than the Cartilages.
  The inner  side of the Trachea is lined with a very
Vascular and Irritable Membrane, continued from the
Mouth, and forming at last the  extreme  Branches of
the  Trachea, which  terminate  in  the  Cells of the
Lungs.
  The inner Membrane ofthe Trachea is every where
perforated by the Ducts  of Mucous Glands, and by the
Mouths ofthe Exhalent Arteries, the former pouring out
Mucus to lubricate the  Lungs,  the other the Vapour
which is thrown off in Perspiration.
  Three different kind of Glands are connected  with
the Trachea,—the  Thyroid, the Tracheal, and the Bran-
chial-
  The Thyroid Gland has its name from  its connection
with the Thyroid Cartilage, though more immediately
connected with the Trachea.
  It is a large reddish mass, situated at the under and
fore-part of the Larynx,  behind  the Sterno-hyoid and
Sterno-thyroid Muscles.
  It has  two  Lobes placed at the under  and  lateral
parts of  the Laymx,  descending a  certain way upon   *'
the Trachea and Esophagus.
  The  Lobes  are  joined by an intermediate  portion,
which lies across the upper and  fore-part of the Trap
chea.
  Sometimes  a Process from the middle portion as-
cends between the Sterno-hyoid Muscles, and is lost
behind the Base ofthe Os Hyoides.
  This Gland has a Grandulous appearance within, and
a viscid Liquor is sometimes observed in it, which has
been supposed by Sabatier and others,  to lubricate
the parts in the neighbourhood.
  It is supplied with large Blood-vessels, and with se-
veral Nerves, from those ofthe Larynx ; it is likewise
furnished with numerous Lymphatics,—but no Excre-
tory Duct has yet been observed to come from it; nor
is its office yet understood. 
1UU
  The  Tracheal Glands are small, -but numerous, and
of different sizes, surrounding the Muscular coat ofthe
Trachea, and its Branches in the Lungs ; the largest
of theni are placed in the Fleshy Substance behind.
  From each of these Glands a small duct issues, and
throws out a Mucus, to defend the inner Surface of the
Trachea from being injured by the Air,  or by the ex-
traneous particles which it carries along with it.
  The Bronchial Glands are placed in the Cellular Sub-
stance round the under end of the Trachea and roots of
the Bronchi, where these penetrate into the Substance
ofthe Lungs.
  They are of various sizes, from that of the point of
the little Finger to that ofthe Millet-seed, and have a
bluish or black colour, corresponding in a great  mea-
sure with the colour ofthe darkest parts ofthe Lungt.
  They were formerly considered by  many Authors as
sending Fluids to  the Trachea, but are now sufficient!^
known to be entirely ofthe Lymphatic kind,—the Ab- i
sorbents of the Lungs passing through them in  their
way to the Thoracic Duct.
  The Trachea is furnished with Blood-vessels from the
Inferior Laryngeals, and Nerves from the Recurrent*
and great Sympathetic Pair.
  The Trachea serves to convey Air into, or out from
the Cells ofthe Lungs, during Respiration, and to car-
ry off the Perspirable Matter from  their Arteries in
time of Expiration.
  The Blood-vessls  of the Lungs consist of the Pulmo-
nary and Bronchial vessels; the one for the general cb>'
culation, the other proper to the Lungs.
  The  Pulmonary  Artery  arises from  the top ofthe
Right Ventricle, divides, like the Trachea, into Right
and Left Branches, which are dispersed through the
substance ofthe Lungs.
   The minute Branches running in the common Cellu-
lar Substance, form at last a Plexus upon the proper
Cells, sometimes  called Rete Mirabile,  and Rete Vas-
culosum Malpichii, from which that Halitus is de-
rived, which is expelled by the  Lungs in Expiration.
   The Pulmonary veins are commonly observed to be
 smaller in proportion to  the  corresponding Arteries,
 than Veins are to Arteries in other parts*of the Body, 
107
which has been supposed to be owing to the large quan-
tity of Fluids expired.—They  join into four principal
Trunks, which terminate in the left Auricle.
  The Bronchial Arteries arise by three or four small
Branches, one of which is from the right  Superior In-
tercostal,  the rest from the Trunk ofthe Aorta.
  They are dispersed upon the Branchi and Bronchial
Glands, and substance ofthe  Lungs in general, and are
found to communicate with the Pulmonary Artery.
  The Bronchial Arteries are supposed to serve for the
 nourishment of the Lungs and secretion of the Mucus.
  The veins return the Blood to the Vena Azygos, and
 left superior Intercostal Vein.
  The Lymphatics form a Plexus upon the Surface of
the Lungs :—They communicate freely with the deep-
seated Absorbents, and pass through  the Bronchial
 Glands.
  The Nerves ofthe Lungs  are partly from the great
Sympathetics, but chiefly from tlie  Eighth Pair, and
are rather small in proportion to the bulk of the organ
on which  they are  dispersed.
  The Lungs serve the general purpose of Respiration,
 which censists of Inspiration and Expiration, or the pas-
 sage ofthe Air into or out from the  Lungs by the al-
 ternate dilation and contraction of the Thorax.
  Inspiration is'performed in consequence ofthe Thorax
 being dilated by the action chiefly  ofthe Diaphragm and
 Intercostal Muscles ; the Lungs, which are passive, and
 in contact with the Thorax, following it,  and the Air
 rushing into the Trachea by its own  gravity.
   Expiration is performed in consequence of a relaxa-
 tion  of the Muscles which  dilate the Thorax,—of the
 Abdominal and a few other  Muscles,—ofthe elasticity
 of  the  Cartilages of the Ribs, likewise of the Lungs,
 by which the Cavity of the  Thorax is diminished,  and
 the Air is expelled from the Lungs.
   Upon the alternate states of Inspiration and Expira-
 tion, depend the formation  of the voice, the sensation
 of Smell, and all the other functions of the .Body :  but
 the great and principaroflicc of the Lungs, which  was
 formerly supposed to be that of cooling the Blood-over-
 heated by friction, is, during Inspiration,  to receive
 from tlie Atmosphere pure  Air. upon which the princi- 
108
pie of heat and life depends ; and, during Expiration,
to carry off an impure  Air, which is noxious to Ani-
mal Life.
  According to late experiments, it appears, that the
Venous Blood passing to the Lungs, of a dark red or
purple colour, is charged with Carbon or Charcoal, and
Hydrogen, or Inflammable Air ;—that while circulating
upon the Bronchial Cells,  one part of the Oxygen, or
Vital  Air, contained in the common  Air,  which  hu
been inspired, unites  with  the  Carbon and Hydrogen,
and forms Fixed Air and a Watery Halitus, which are
carried  off" by Expiration ;—that another part  of the
Oxygen is imbibed by the Blood, which, in consequence
of these changes, returns from the Lungs, of a florid
red colour, and full of heat in a latent state, which be-*
comes sensible in the course ofthe general Circulation,
and is diffused over the different parts of the Body ; and
—that the Blood thus changed also affords a stimulou
to the  Arteries,  and promotes  the  different  Seer
tions.
                    Esophagus-

  The Esophagw, called also Gula or Gullet, derives its
name from carrying what is eaten into the Stomach.
  It is a Fleshy Canal, which begins from the inferior j
part of the  Pharynx, descends along  the  Neck, and:
through the Thorax, following nearly the direction i ~*
the Spine.
  It is situated between the Trachea anel  Vertebrsjf
and in the Thorax, it proceeds behind the Base of The
Heart,  and between the Layers of the Posterior Me-
diastinum, from which it receives a lateral covering.
  Soon  after entering the Thorax, it. makes a slight
turn to the right, and passes down upon the fore and
right  side of the Aorta, by which they are preventtjlfc
from injuring each other.                         ■*!
  In its progress, it inclines more forwards and to thej
left side ; and about the Ninth Vertebra of the Thorax,;
it perforates the Muscular part  ofthe  Diaphragm, and
terminates in the upper Orifice ofthe Stomach.
  It has several coats proper to  it, the first  of which is
Cellular, and connects it to the adjacent parts.
  The second Coat is Muscular, and is sometimes ter- 
rned vaginalis Gul*,—It consists of two Layers;  thd
external of which  has thick, strong,  longitudinal  Fi-
bres; the internal is formed of  circular and transverse
Fibres, and  is thinner than the former.—The  outer
Layer is fitted for shortening and relaxing, and the in-
ner for contracting the Canal, during Deglutition.
   The third  Coat is  termed Nervous, but is properly
Cellular, being formed of  loose Cellular Substance,
which connects the Muscular to  the Inner coat.
   The Inner coat is continued from the Lining of  the
 Mouth i It consists of many longitudmal  Plica or Folds,
 which are scarcely visible when  the  Esophagus is dila-
 ted,  and is furnished with numerous Foramina, which
 discharge a Mucus for lubricating the passage, and fa-
 cilitating Deglutition.
   The Arteries of  the Esophagus are  Branches of  the
 Inferior Laryngeals, which supply the Curvical part of
 it, and Esophageal and Branches of the Bronchials,
Avhich are derived from the Aorta Descendens, and
 supply the Thoracic part of it.
   The Veins go to the Inferior Laryngeals, to the Vena
 Azygos, and left Superior Intercostal Vein.
   The Absorbents are  numerous, and  intermix with
 those ofthe Heart and Lungs.
   The Nerves are  chiefly from the Eighth Pair.
   The use of the esophagus is, to receive the Aliments
 from the Pharynx, and convey them to the Stomach.

                    Thoracic Duct.
   The Thoracic Duct is a small Membraneous-like Canal,
 situated in the back-part of the Thorax, and is the prin-
 cipal Trunk ofthe Absorbent System.
    It begins upon the third Vertebra of the Loins,  and
I passes behind the Aorta, crossing obliquely from left to
 right* till it gets to the right side of that Artery.
    Upon the first Lumbar Vertebra, it forms an Oval Sac,
 termed Reseptaculum  Cbyli, which is placed behind the
 Right Cms of the Diaphragm,  and a little higher than
. the Right Renal Artery.
    The  Duct afterwards passes between  the  Crurao£
c: the Diaphragm, and ascends in the Thorax, on the ante-
 rior part of the spine, between  the layers of  the post?'
      VOL. n.               " 
110
rior Mediastinum, on the right side of the Aorta, a.,.-,
between it and the Vena Azygos.
   It crosses behind the  upper part  of the descendin
Aorta,  and emerges from the Thorax, to reach the un-
d  i" part ...f the Neck.
   In the Neck,  it passes behind the  Internal JugjrVr
Vein, and a little higher than the Subclavian.
   It then turns  downwards,  forming an  Arch,  wjn'cd
terminates in the upper part ofthe Angle, betweetvthe
Internal Jugular and Subclavian of the Left Side.
  The Thoracic Duct receives tlie Chyle from the Lac-
te?ls, and Lymph  from the Lymphatics, and dischai*
these into the red Veins.                          jp.
            OF THE  ABDOMEN.

   The Abdomen or  Belly extends from the Thorax'
 the under part of the Trunk.                       ^
   I   is bounded above,  by the  Diaphragm, and the
 Bcnes to which that Muscle  is  fixed;  below, by ttofi
 Pelvis; behind," by-the Lumbar Vertebra:  and Musdeij
 of i-he Loins;  anteriorly,  by  its  proper Muscles; gJ
 laterally,  by the False Rib.,  Ossa  Ilri,  and MuJH
 connected with these;—all of which have  been descH
 ed in their places.
   It is distinguished into three  Divisions or Regions,lfM
 med Upper,  Middle, and U\,dtr  Region;  each of  whifl
 is subdivided into three others.
   The Upper- Region  begins opposite  to the Cartilago
 Ensiformis,  at a  small  depression  called  Scrobtnlm
 Cordis, ot Pit of the  Stomach,  and extends to about 1
 hand breadth from the Umbilicus or Naval.
   The middle of this Region is termed  Epigastrium, d
 under part ofthe Eelly, and the two lateral parts Hypo
 candria, from  their  lying under the Cartilages of the
 Fal '• Kibs.
   The Middle Region occupies  an equal distance aboi
 at;d below the  Umbilicus.—The middle part of it is cal-
 led \-.\ Umbilical, and its  lateral  parts the Lumbar Re-
gions or Loi:.s. 
  The Under Region begins  where the middle  one  ter-
minates, or at a line drawn between the stmerior ante-
rior Spinous Processes of  the Ossa  Ilii, and  forms in
the middle,  the Hypogastrium, or'bottom of the Belly;
and at the sides, the Iliac Regions.
  The Abdomen is covered on the outside  by  the com-
mon  Integuments, and  lined within  by the  Peritoneum,
in the manner  the Thorax is lined by the  Pleura, but
without being  divided by  the intervention  of  a  Parti-  i
tion.
   The  Abdomen  contains  the  Chylopoetic and Assistant
Chylopoetic viscera or  Organ  of  Digestion,—the Organs
of Unne, and part of those of. Generation, with the vessels
and Nerves which belong,  some of them to these Visce-
ra, and others to the lower parts of the Body.
  The  Chylopoetic Viscera   comprehend the Stomach,
which is situate! in the upper and left part of the Ab-
domen—the Intestines, which fill  the greater part of it,
—and the. Membranes,  termed  Omenta and  Mesentery,
which are connected with these.
  The Assistant Chylopoetic  Viscera consists of the Liver,
wtlich  is placed in the upper  and right;  of the spleen,
which is situated  in the  upper and left side  of the Ab-
domen;—and  of  the  Pancreas,  which lies  under the
Stomach.
   Of the Organs of Urine, the Kidneys are placed in the
back-part of the Abdomen, and the  Bladder, with some
ofthe Organs of Generation in the Pelvis.

                      Peritoneum.
   The  Peritoneum, named from  its being  stretchrd or
spread  around  the bowels, is a  firm but simple Mem-
brane, by which the Abdominal  Viscera are surround-
ed, and partly  supported.
   Its External Surface is rough and Cellular, and close-
ly connected with the parts to which it belongs.
   The  Internal Surface is remarkably smooth, and lu-
bricated by  a  Liquor which is  exhaled from its own
 Vessels.
   It is very elastic,  and admits of great extension, as
happens in  Gestation,  Corpulency,  or Ascites; but,
 upon the causes of extension being removed, it returns
 to its former dimensions. 
112
  It lines tl»e Diaphragm, passes downwards, adhering
firmly to the Abdominal Muscles,—lines the containing,
and covers the contained parts of the Pelvis, from which
it is reflected in the back part of the  Abdomen, lining^
its Muscles,  and, by its  reduplications, covering the
Bowels,and great Blood-vessels of that Cavity ;—though. >
strictly speaking, the Abdominal Viscera may be said to  1
lie on the outside of it.
  In its passage from one Bowel to another, it forn§
doublings which serve as Ligaments to fix them to eaclt
other, and likewise to the Body.
  It gives a general covering to  most  of the Bowels, a
partial one to a few, and to those which are deep-seated
and project least, a still more  partial covering.
  It forms a large Sac, the posterior part of which ad-
heres firmly  to the different Viscera* and the anterior
to the Abdominal Muscles;—the part  lining the Ab-
domen being merely in  contact with its contents, and
allowing a small degree of motion.
  The  Cellular Substance, on the  External Surface of
this Membrane, is not every  where of equal thickness, j
being In some  parts,  as upon  the  Bowels,  remarkably
thin; in others, as over the Kidneys, filled with a con-
siderable quantity of Fat.
  The  Cellular Substance forms various  Processes or
productions, some of  which, as those on the Spermatic,
cords, pass through Foramina, to be connected with the,
neighbouring  parts; and  the processes  are  sent  off,
without affecting the Internal  Membrane, the one not
accompanying the other.                            ,
  The  Vessels and Nerves of the  Peritoneum are  fronj
those which supply the contiguous  parts; its Vessels,
however,  are  not very  numerous; neither does it pos- i
sess much sensibility when free  from disease.
  The  Arteries come from the Internal Mammary, Epi-.
gastric, Inferior Intercostal, Lumbar, Sacral, and Ileo-
Lumbar  Arteries, and  from those which supply the
Abdominal Viscera.
 1 The  Veins  have the same course, bear the same names,
and in  general pass to the Inferior Cava.
  The Absorbents are numerous, and  run chiefly to the
Iliac and Lurnbar Plexus.
  The  Nerves, which are few in number and small, are 
from the Inferior Dorsal,  the Lumbar, the Great Sym-
pathetic and Sacr:.! Nerves.
  The use of the Peritoneum is to  line and strengthen
the Cavity  of the  Abdomen ;. to inclose and assist in
supporting its  dilierent  Viscera; to  furnish most ot
thern with  an External coat; to connect  them  to  the
Bod.,  and, by its smoothness and slipperyness,  to pre-
vent the effects of Frictjon.
  Upon the outside of tie Peritoneum are Four Wh te
Lines, or small Cords, three of which are Vessels in the
Firtus,—one of them a Vein, and two of them Arteries;
the fogrth is  the Uirachtis.—In the  Adult, they  are
shrivelled up,  and serve as Ligaments, the  Vein form-
ing the Round Lig-iment of  the Liver, the three other
Cords, fomliuj Li0ainents ofthe Bladder.
                    STOMACH.

  '  The Stomach is a large Bag or Reservoir, situated ob-
  liquely across the upper and left part  of the Abdomen,
  in the left Hypochondriac arid Epi^i'^ric Regions.
    It is turned downwards  and  forwards, so as to form
  an angle with the Iv-.opha^us, the angle becoming more
  conspicuous, according to tbe distension ofthe Stomach,
    The right part of the Stomach is  situated unib-r the
  left part of the Liver, the  rest of it  is placed immedi-
  ately under the Diaphragm, its extremity being in con-
  tact with the Spleen.
    The Stomach'is long, round,  and  tapering, and has
  been compared in shape t<» the Bag of a Bagpipe.
    'The size is in propoition to tb» quantity of Aliment
  it has been accustomed to  receive,  and  therefore  is
  commonly larger in men than in Women.
    It has a Large and Small Extremity, an  Upper and
  Un-ler Surface, a Great and Small Curvature,  a Left and
j  Right Orifice, and consists of several Layers or Coats.
 ,  The Large, called also the Left Extremity, is situated
tx in the left side of  the  Abdomen,  and  is  considerably
  higher than  the Right.
                          c 2 
114
   The Upper Surface is turned towards,  the  Diaphragm
 the Under  towards the Intestines;—but when the Ab-
 domen is laid open,—unless the Stomach be considera-
 bly  distended,—the Superior Surface becomes anterior,
 and the Inferior Surface posterior.
   The Large Curvature is turned obliquely forwards and
 downwards towards the Abdominal Muscles, and ex-
 tends from one Orifice to  the other.
   Tb,e Small Curvature is opposed to  the  other, and
 turned backwards and upwards, towards the Spine, ex-
 tending also between the two Orifices.
   The Orifices are next the small Curvature.  The left
 js termed Cardia, or Os Ventriculi, or Upper Orifice ofthe •
 Stomach.—It is opposed to the  Spine,  at a  little dis-;J
 tance from it, and is formed by the termination of the
 Esophagus   It allows a free passage for the Food into j
 the  Stomach, the return of which is prevented by the!
 Angle formed by this part of the Stomach, and by the J
 Fleshy parts of  the Cardia, and of the Diaphragm in I
 which it is situated.                                   '
   The Right, or  Inferior Orifice,  is commonly termed
 P.lorus from |ts  Office as a Porter.
   It. is situated under the  small Lobe  of the- Liver, a |
 little to the right side  of the  Spine.—is turned  more
 forwards than the  Cardia, and is considerably lower, but1
 rises in proportion t'o the distension q£ the Stomach.
   The Stomach is connected by the Cardia to the Esoj
 phagus.—by the Pylorus to the  beginning  of the Intes-
 tiv»e»,-r-by  the Peritoneum and   Blood-vessels  to the
 Spleen,—and by a reflection  of the Peritoneum to the
 root of the  Liver and to the Great  Intestines.          ,
   The Structure of the Stomach is in general similar to
 that of the Esophagus, of whitdi it is a  kind of Expan-
 sion.
   X he coats of the Stomach we four in number.
   The first or External coat, called also Peritoneal, is a i
 Reflection of that part of  the Peritoneum which  comes
ft'.'fn che rooi of the Liver.              '             «
   I  ;:i«ngthens- the Stomach ; by its smoothness it di-1
 mhv-hts the effect of Friction,  and  possessing few j
 Nerves or  Blood-vessels,  it. is not \ery susceptible of
 pain or inflammation. 
115
   The Cellular  Substance under the Peritoneal Cover-
 ing, is  described  by some authors as a  distinct  coat,
 called  Tunica Cellulvsa  Ruyschiana;—but ought not to
 be numbered among the coats ofthe Stomach.
   The Second or Muscular coat is composed chiefly of
 two planes of Fibres variously disposed.
   The External Plane is longitudinal, extends from the
 longitudinal  Fibres  of the  Esophagus, and follows the
 same general course with that of the Stomach from the
 gteat to the small  Extremity.   "
    Upon each side  of the  bra all Curvature, the longitu-
 dinal Fibres  form  a thick, strong. Muscular Band.
    The second Plane  is  chiefly  transverse or circular,
 ard considerably thicker and stronger than the other.
    Its Fibres  are intersected  by rrfany small, white,  Ten-
 dinous-like Lines;—these, however, are m a great mea-
 sure formed  of that  Cellular Substance  by  which the
 two coats are united.
   The Muscular Coat  assists  in the digestion  of the
 food,  by giving a gentle motion to the Stomach, accord-
 ing to the direction of its Fibres, the one set shortening,
 the other rendering it narrower.
   The P\lorus is formed by a doubling of the two in-
 ner coats, which project  into  the passage between the
 Stomach and Intestine, and contain a Ring of Muscular
 Fibres, which form a Spincter, called Spincter  Pylori.
   This substance,  by contracting, prevents the grosser
 indigested parts of the Aliment from escaping, and, by
r dilating  allows the Pulpy digested part  to pass to the
 Intestines.
   The Third Coat, commonly called  Nervous,  but prop-
 erly Cellular,  consists of a large quantity of fine Cellular
 Substance,  without Fat, and is intermixed with, and
 supported by small Aponeurotic-like Filament^, which
 cross each other obliquely, but which are also  of a Cel-
•, lular nature.
   This coat strengthens  the Stomach, and allows the
 Vessels to be distributed  to the Inner coat, with whicli
t it is intimately connected.
   The Fourth or Inner Coat, called also Villous, from its
. resemblance  to Velvet, is continued from the Inner Coat
 ofthe Esophagus, but is much more Villous.—It is for-
 med of  fine, short, prominent Villi, which are crowded 
                        116

with Small Vessels,  some  fir furnislimg -i Mucous Li-
quor to the Stomach,  others for  absorbing a  portion of
the thinner jia^t ofthe Food.
  The two h.;t  coats  are more extensive than the mt,
and form, iqion  the inner part of the Stomach, many
doublings, termed Ruga, the greater number  of  which
run iu  a waving transverse direction, and are afterwards*
divided into  a  sort of  Xet-\-jrl:.  Near  the  Orifices,
however especially  towards the upper  one,  they  run
more in a  longitudinal direction, and haye a radiated  |
appearance at the Cardia.
  The Rugae, like the  Plica: of the Esophagus, are most  I
distinct when the Stomach is empty,—wb^n  lull, they  ft
are much less evident.                                 1
  They admit of distension without endangering the  M
Vessels and  Nerves dispersed in  them, and assist a lit- jl
tic in detaining the Aliment till properly digested.    ^hS
  From the inner surface ofthe Stomach a liquor issuepiH
which  is found to approach to the- nature of Saliva, and W
is termed Gaitric Jutce.— This was formerly  supposed  M
to come from Glands  seated in the  Third Coat, but is  1
now more frequently considered as a Secretion from the M
Arteries ofthe Stomach, no Glands t-eing evident there,  |
at least in the sound state of th;s Viscus.             .  ^1
  The Arteries of  the  Stomach are derived from thojfl
Cceliac Artery.  They consist of the Superior GastricJfiS
which  supplies the place next the small Curvature ; thJH
Right inferior Gastric, which is a branch ofthe Hepjfl
tic;  the  P)loric Arteries, which are  small  branchjipH
from the Gastrics and  from the  Hepatic ; and of the. ■
Left Gastric  and Arterix breves, which  are  branches
of the  Splenic Artery.
  'The Veins  have the same names, and nearly the sam«  M
course  with the ArtPries.   The whole of them  termi- fl
nate in tlie Vena Port^.                              ^
  The  absorbents of the Stomach  are  numerous  and  m
large.  '1 hey pass  through small Glands situated upon fl
the  Curvatures,  and go  afterwards to  the  Thoracic  11
Duct.                                                 J
  They appear to carry Lymph only, no  Chyle having  1
been Oetected in them, even in cases where the Lactc-  1
als  were found full of it.                               *
  The  Nerves are ehicHy  from  the Eighth Pair,  and 
117
partly from the Great Sympathetic*,  and are  most nu-
merous upon the Cardia.
  The Stomach receives the Food from the Esophagus,
and afterwards prepares it, by digestion,  for the Intes-
tines.
  'The digestion of the Food in the Stomach is found to
be effected.-r-by  Triture, which is performed by  the
motions of the Stomach and surrounding Muscles,—by
dilution,—by a partial fermentation,—but chiefly by the
actionvof the Gastric Juice serving as a Menstruum.
                INTESTINES.

  The Intestines consist of  a long Cylindrial Canal,
which begins at the Inferior Orifice of the  Stomach,
and, after winding in various directions, terminates in
the  Anus.
  In genera! they are about six  times the length of the
Body to which they belong ; though, in a person of short
stature, the proportional length  of the Intestines is
greater, and vice versa.  m
  They occupy  a large part of the abdomen, and are
connected to the Body through their whole extent, by
a doubling ofthe Peritoneum.
  On account of the inequalities of their size, they are
divided into Small and  Large Intestines,  and each of
these is subdivided into others.
                   Small Intestines.
  The  Small Intestines are smooth on  their outer Sur-
face, and of a tapering form  becoming gradually  less
in their diameter  from  their  upper to their under ex-
tremity,  and are divided into the Duodenum, Jejunum,
and Ilium.
  The Duodenum, so called from its being about twelve
fingers-breadth in length,  begins at the Pylorus,  and
makes a short turn upwards and backwards, by the
Neck of the Gall-bladder,  to which it is contiguous, 
118
having the Anterior Layer of the Omentum fixed to its
inferior part, and the  Omentum Tvlinus to its  opposite
aid**.
  It then passes obliquely downwards  and to the right
side, before the great  Vessels which go into the Liver,
and likewise before the Renal Artery and Vein, includ-
ed in the Cellular Substance ofthe Mesocolon.
  Opposite to the under part of the'Kidney, it makes a
turn to the left side, where it is lodged in the common-
root ofthe Mesocolon and Mesentery, and receives into.
its back-part the  ends of the  Biliary and  Pancreatic
Ducts, and goes over the Aorta and Vena Cava,  oppo, J
site the last Vertebra ofthe Back.
  In passing  across these Vessels, it  is involved in the
root of the Mesentery, and ascends a little till ir gets
to the left side of the Spine,  where  it  perforates  the
common root of  the  Mesentery  and  Mesocolon, and
makes  a turn  forwards, where it obtains the name of
Jejunum.
  The Jejunum so named from its being commonly more
empty  than the other Intestines,  in consequence of  the
thinner parts of its Contents being sooner absorbed, be-
gins at the latt turn  of the Duodenum, and forms nu-
merous Convolutions, which run in all directions,  and
are situated in the upper part ofthe Umbilical Region. ?,—
  The Ilium, np.med  from its numerous Turns, begins
where the Jejunum terminates, or where the  Internal
Plicse  become  less  conspicuous,  and  is distinguished
externally from that  Gut,  by being  smaller, thinner in '
its coats, and paler, and from its  forming about three- '
fifths of the length ofthe two Intestines.
  The Ilium, like the Jejunum, forms many convolutions,
which are situated on the under part  of the Umbilical
Region, and extend as far as the  Hypogastric and Iliac
Regions, and not unfrequently, especially in Women,
into the Cavity of the Pelvis.
   It-surrounds the lateral parts of the Jejunum, and is
supported  by  t'le Ossa Ilia;  and, the last turn of the
Gut passing across towards the upper edge of the Right
Os liium, it  terminates  by  a Valve in the left side of
the beginning of the Colon.
  Through the whole of this course, the Jejunum and 
                         113

 Ilium are fixed to the Spine  by a continuation of  the
 Mesentery.

                    Great Intestines.

   The Great Intestines, like the Small, form one continu-
 ed Can.l, which tapers from  its upper to near its under
 extremity; but differ from them in being  considerably
 larger, shorter,  and straighter, and  in being irregular
 in their Outer Surface, and tacked up into  Cells,  hav-
 ing besides many Processes depending from them,  ter-
 med Appendicul* Pinguidenosa.
    Like the Small  Intestines, also, they are divided into
 three j.ans, termed Cxcum, Colon, and Rectum.
 '■  The Intcstinum Cacum, or Blind Gut,  forms around
rshort Bag, only about three or  four Fingers-breadth in
 length, and nearly the same  in  dian\eter.   The Cxcum,
 properly so called, is that part of the Intestine which lies
 under the insertion of  the Ilium, though  frequently the
 dilated beginning of the Colon  is  distinguished  by the
 same name.
   It  is sittiated in the Right Iliac Region, resting on the
 Cavitv of the corresponding  Os  Ilium, at the under
 end of the Right  Kidney, and is concealed by the last
 Convolutions of the Ilium?.
   The bottom of  it is turned  downwards and forms a
 shut Sac, the  mouth  of which is turned towards  the
 Colon, and may be considered  as forming the  Gacum
 Caput Coli.
   At the posterior and left side of  the C<ccum,  there
 is z small Process,  about the  same length with the Cae-
 cum itself, but the diameter not  larger than  that of a
 Goose-quill,—termed  Appendix Vemi/ormis,  from  its
 resemblance to an Earth-worm, and Appendix Caci, from
 its connection with the Cscum.
   It is convoluted, and fixed by its sides to the Czcum.
    It has two extremities, one  of  which is impervious,
 the other opens obliquely into the back-part of the  Cse-
 en m.
   The Colon, so called from the Gree!<, is by  much the
 longest of the lar;;e Intestines.  It encircles  the Small
 Guts, and is contiguous to most of the Abdominal Vis-
 ed a. 
             „         120

  It is a continuation of the Catcum,  beginning at the
termination ofthe Ilium.
  It ascends in the  Right Lumbar Region, over the
Kidney of that side to which it is connected.
  From the Kidney, it passes forwards, and crosses the
Abdomen  in the Epigastric and Hypochondriac Regions. !•'
connected to the  Duodenum,  under the name of  Great
Arch of the Colon.
  The right portion of the Great Arch is situated un-
der the  Liver and  Gall-bladder, which,  after deathT
commonly tinges part of it and of the Duodenum witit
Bile.                                              "i
  The left portion is situated  under the Stomach ; and
immediately below the Arch are the Convolutions of the
Jejunum.
  In the Left Hypochondriiim, it turns backwards un-
der the Spleen, and descends in the  Left Lumbar Re-;
gion, on the foreside of the Kidney, to which also it b
closely connected.
  In the Left Iliac Region, it forms two Convolutions
compared in shape to the Greek Sigma, and hence cal- ,
led Sigmoid Flexure of the Colon, which afterward scon-i
stitutes the Rectum.                               ™;
  The Sigmoid Flexure varies  considerably in length in
different persons, extending frequently into the HyptvA
.gastric Region, and in some  instances,  as far as  tha
Iniesunum Caecum.                                 t^
  The Colon, through its whole extent  is fixe*d to tlfll
Body by means ofthe Mesocolon.
  The Rectum begins at the last  Lumbar  Vertebra, and
has its name from appearing straight when viewed an-
teriorly.
  It descends upon  the fore-side of the Os Sacrum an
Os  Coccygis, and terminates  in  the  Amis,  a  little be-
yond the extremity ofthe last named  Bone.
  in its course, it follows  the direction of  the  Bone
over  which it passes, turning first downwards,  then a|
!ittle backwards, then forwards, and is fixed to them byj
the Mesorectum.
  The Rectum differs from the other Intestines, in be--.
coming wider in its progress  downwards, and  forming
he low a Reservoir for the Fxces.
n- 
  At the Anus, it contracts into a narrow Orifice, the
sides of which are  disposed in close longitudinal folds.
  Upon  the Outer Surface of the Great Intestines, but
more especially upon  the Colon,  are  the Appendicul*
Pinguedinosa situated at  different distances from  each
other,—thin at their roots, becoming thicker  in their
bodies, y?A projecting from the Intestines like so many
pendulous Papillae.                  #
  They  are covered by the Peritoneum, and are of the
same structure and use with the Omentum.
   Besides tlie  Appendiculae, there are on both sides of
the  adhesions of the Mesocolon,  Adipose Strata, which
are of the same nature with the others.
   The Colon is divided longitudinally, into three parts,
by  as many Ligamentous like Bands, which  run upon
its Surface.
  One of them goes  along each side ofthe Colon : and
that most exposed to view when the Omentum  is sepa-
rated, is the largest: The third, which is the smallest,
and which was discovered by Morgagni, is concealed
by the attachment of the  Meso-colon.
f-They begin  at .the  root ofthe Appendix Vermiformis,
tnd,  after running along the Caecum  and  Colon, unite
Into two, and then terminate on th-' Rectum.
                     Mesentery.
  T;ts  Mesentery  is farmed by a doubling of the Peri-
toneum, which is detached forwards, and includes the
Intestines as in a sling.
   It is named  from its situation in the middle of the In-
testines, and is divided into two parts One connecting
the small Intestines, and retaining  the name of Mesen-
tery ,- the other, the Great Intestines, and termed Me-
socolon.
  The Mesentery begins at the last turn ofthe Duode-
num, and runs obliquely downwards and  towards the
right side, along the Vertebrae of the Loins, to the  first;
second, and third  of which it is chiefly connected.
   Between tlie two Layers of the Mesentery, are inclo-
sed  a considerable quantity of Cellular Substance and
Kat,  the numerous Blood-vessels and Nerves, with the
Lacteal* and Glands ofthe Jejunum and Ilium.
   Its anterior edge  is much more extensive than the
     VOL. II.              H 
122
posterior, being platted and  folded,—the Plaits corns.
ponding with the Convolutions of the intestines to which
it is fixed.
  The Me-io-colon is the continuation of the Mesentery,
which, after reaching the lower extremity of the Ilium,
contracts, and obtains this name.             a
  It follows the course of the Great Intestines, and fixes
them  in their plfce.
  Under the  Right Kidney, it is narrow and firm, and
forms the Right Ligament of the Colon.
  Opposite the Kidney, it appears to be lost by the im.
mediate adhesion of the Colon to the Kidney and  Duo
den urn.
  It then turns across, and  forms a  broad expansion,
which incloses the Arch  of the Colon at its anterior
edge ; and behind, it separates and incloses  the anterior
part of the  Duodenum, and is fixed to the Spine.
  It adheres a little to the under part of the left extrem|
ty ofthe  Stomach, and afterwards descends over the, Jef
Kidney, at the under end of which it forms the Left Li-
gament ofthe Colon.
  It  afterwards  expands, adheres to the large Psoas
Muscle, and forms a  loose fold,  which detains the Sig-
moid  Fletilre ofthe Colon.   •
  At the last Vertebra of the Loins, it forms the Met
rectum, which by degrees becomes narrower, and disa;
pears towards the under part of the Pelvis, the  Rect
being then  immediately connected to the Os Sacrum,
  Between the Layers ofthe Meso-colon are placed t
Arteries, Veins, and Nerves, with the  Absorbents and
Glands ofthe Colon.
  The use of the  Mesentery, in  general, is to suspend*
connect, and retain  the Intestines in their places,—to',
furnish them with an external  Coat,—to receive their
Glands, Vessels, and Nerves, and to allow  the  two last <
to be properly distributed.

                     Omentum.
  The Omentum or Cawl, formerly called Epiploon, from
its seeming to float upon the Intestines, is a tine Membra-
nous  Bag,  intermixed with much Fat,  and  covering a
large portioir of the Anterior Surface ofthe Abdominal
Viscera. 
123
  It is divided into Omentum Gastro-Colicum, and Omen-
tum-Colicum,  the  former common to the Stomach and
Colon, the latter  proper to the  Coloh : They are, how-
ever, a continuation of one and the same substance.
  The Omentum Gastro-Colicum  consists of an anterior
and posterior part,each  of which is formed of two Mem-
branes intimately united.
  in young subjects, the Omentum forms a distinct Bag,
but in  old people, the Layers of  v Inch  it is composed
become more or  less incorporated,  and Cribriform or
Reticular.
   The Anterior Layer  is a continuation of the  Perito-
neal Coats, produced from  the  upper and under Sur-
faces ofthe Stomach.
   This Production arises from the whole length of the
large  A i eh ofthe Stomach, and beginning ofthe Duode-
num ;—its origin  extending  as far as the  Spleen,  and
descending to a little below the Umbilicus, especially in
fat people,—but  without  adhering  to the Abdominal
Muscles behind which it is situated.
  Its under edge is reflected to form the Posterior Layer,
which ascends without adhering to the Small Intestines
over which it is spread, until it reaches the Arch ofthe
Colon, to the greater part of which  Arch,  and the Ves-
sels of the Spleen, it is connected.
  The Omentum Colicum arises from the right part ofthe
Arch of the Colon, in the manner/the other j art of the
('mi ntum arisesfrom tl)e Stomach.and tends dow mvards
and to the right side a Cuneiform Piocess, to be connect-
 ed to the Caecum.
   Besides the Omentum,  there  is  a  Membrane much
 smaller than the  former, shinned beiv mi the I her and
Stomach, termed  Omentum  Htpato-gastriaim, or Omen-
tum Minus, of \V insi.ow, or Membi una  Mucilentiof of
Haller from its having little Fat in it.
   It passes from the fore-part of the Sinus  of the  Porta,
to the under and  back part ofthe Liver, to be connected
to the w hole ed^e of the small Curvature of the Stomach,,
and to the beginning of the Duodeiu.n'.  '
   Like the other Omentum,  it is composed of two Lay-
ers, but is thinner,  less Fat, and more  uniform in its
 mruetnre, and also dii.iik fiom it in  having no leflectiou
upwards. 
                        124

   After the Omentum Minus reaches the Stomach, its
 two Layers separate from each other, inclose that Viscm
 and form its external Coat
   At the Great Curvature ofthe Stomach they rejoin,
 form the Anterior, then the reflected or posterior part
 the Omentum Majus.
   The posterior part separates again into  two Layeij
 which inclose the Colon, and fo.m its external Coat, j
   At the opposite side of the Colon, the Layers re-unifl
 and form the Meso-colon.
   By  the Membrane thus continued, a large irregu
 Bag is formed, of which Jtne^Omentum Minus,  Stomaoi__
 and anterior portion of the Omentum Majus, constitute
 the  anterior, and the reflection of the Large Omentum,
 the Colon, and Meso-colon, the posterior parr.
   At the upper and right side of the Sac, there is a pajfcl
 sage  large enough to admit a Finger, termed Foramm
 Winslowi
   It is situated immediately behind the Cord of the gretl
 Vessels which lead to the Liver and is of a Semicircular!
 form.
   It is composed ofthe Peritoneum, under the appear*!
 ance  of two  Ligaments which connect the  surroundinH
 parts to each other.                                  ]
  The Foramen of Winst.ow maintains a communication!
 between the Large Sac of the Omentum and commoijp
 Cavity ofthe Abdomen,  from which circumstance, Fl?
 ids generated by  disease may readily pass from  one A
 these Cavities to the  other.
  The Omentum, by its Fatty nature, serves to lubricate
 the Viscera,  and prevent them from being injured by
 friction.

       Structure ofthe Small Intestines in General.

  The Stmcture ofthe Small Intestines is nearly similar
 to that of the Stomach, and the number of their Coats the
 same.
  The External Coat, excepting in a proportion  of  the
 Duodenum, is a continuation of that part of the Perito-
neum which forms the Mesentery.  It closely surround*
the Intestines, adhering  to them  by fine  Cillular Sub*
stance. 
12i
  The Second or Muscular Coat,  as in the  Stomach, is
composed of two Planes or Fibres, the External or Lon-
gitudinal of which are more minute than the Internal.
  The Circular Fibres are divunct and numerous :  They
consist of SL.-'Ttents of Circles, which unite at different
distances, so as to surround the Canal.
  The Longitudinal Fibres shorten, and the C'.n-ular con-
tract the Intestines; and upon the alternate relaxation and
•conTaction of these Fibres, depends tnat Vermicular mo-
tion, called Peristaltic, b> which the contents are pushed
through the Canal.
   The  Third commonly called Nervous coat, like that in
ibeSfomach, is w hue and firm and composed of* Celjular
SuJw.ta.nce. without fat;—its  firmness giving strength to
the Intestines.
   The  Fourth, or Villous coat, differs from that of tie
Stomach, in forming w.ith  the  Cellular coat, numerous
traviswisc Folds, termed Val-cuUv coiv.hentes, from  their
j-trviiu;,, as a kind ot Valves to  retard the motion of tlie
Fix'U.
   tine edge of these Valves is fixed to the Iniesnne, the
otlu r is loose.   'I hey are much deeper than the Hug* c-f
the Kionuich, and placid opposite  to the Interstices f>f
each other,  and  aie or clitic-rent lengths, not forming en-
tire Circles.
   The  J ilii ofthe Inner mat are much  more completi-
ons than in  the btomuch, being composed no; only of the
extremities of Arteries, \  tins, and Nerves, but particular-
ly ofthe Mouths of Lacteal Vex els, the Origins of which
arc extremely small, and  have a fungous appearance.
   Numerous  Ducts of Sirnpli: and compt.ur.--t Glands ter-
minate* on this coat, for the secretion of Mucus.
   'i he former are called Solitary, inidtlie latter congregates
and  form their debcribeis,  GlandiiU- plveui, and Llan-
duLe BiuitNH 1.
   'They are in the form of Papilla?, but so minute as sel-
dom to be seen, excepting in  the diseased  state, though
thev arc supposed to be dispersed ovor the whole of the
Canal.
       Structure if the snail intestines in particular.
   The Duodenum is the la>.est and straightest of the Small
Intestines, and so large as to have  been  considered as a
Vtr.tric.ih■■*• Succentu[ii:;us, or Secondary Ston.ach. 
                        126

  It is of a redder colour,  than the  rest, has a thicker!
Muscular coat, receives only a partial covering from the .j
Peritoneum, and is fixed more closely to the Body, with-
out floating like the other Intestines.            -,
  Ft is perforated at the distance of three or four fingers-
breadth from the Pylorus, by the ends ofthe Biliary and
Pancreatic Ducts, for the reception of Bile and pancre^Bl
tic Juice.                                           ^
  In the Duodenum, the Lacteal Vessels begin to make
their appearance, and numerous Mucous Glands are found ]l
in it especially near the l\lorus.
  The use ofthe  Duodenum-is to receive the food  from
the Stomach, and detain it till mixed  with the  Bile and
Pancreatic Duct.
  The Jejunum  differs from the Duodenum, in  derij
ingits common coa- wholly from the Peritonium, in beiff
smaller, in having a weaker Muscular coat, in the  exte
nal Fibres of which are extremely minute, in the Valwu-'
lae Conniventes being larger and more  numerous,—and in
the Villi and  Lacteals which procted fiom them  being;
much mere conspicuous
  The Ilium differs from the former in being less in dia-
meter, and its coats thinner and of a paler colour, and in
having fewer and Smaller Lacteal Vessels. In this Intes-
tine the Valvule  Cpnnivenies gradually decrease in sue
and number, and at length entirely disappear.  At  its u|
der end, the Mucous Glands are distinct and numerous
  The  use of the Small Intestines in general is, to pro-
mote  the formation  ofthe Chvle, to allow it to be ab-
sorbed, and, to propel the remains ofthe Food into the
Large Intestines.

        Structure of,the Great Intestines in General.

  The  Great have the same number of coats with the!
Small Intestines, but differ from -hem in being thicker, and*
stronger.   The Valvula:  Conniventes are deep, and pia-,*
ced opposite to  each other, and  as in the  Small  Intes*.'
tines, diminish in number and in sire towards the under
extremity.  The Villous appearance is much less distinct.
The Mucous Gla«ds are larger, but simpler than those ot>
the Small Intestines. 
127
       Structure ofthe Grewt Intatinrt in particular.
   The Intrstinum caanii is ofthe same general structure
 ■vnh the rest of tbe Great Intestines   Its Villi are very
 abort; and it lias a number of solitary Mucous Glands,
 Broader than those ofthe Small IntesTines, which, when
 diseased sometimes appear like Small-pox, with a perfor-
 ation in each.
   The Appendix Vermifirrnris is  of the same structure
 with th; oiher Intestines, contains no F^ces, bin is fur-
 nished with numerous Glands similar to those of the Duo-
 denum, the contents of which pass into the Ciccum, a lit-
 tle below tbe Valve ofthe Colon, and assist in lubricating
 that Intestine, in faciliating the expulsion ofthe Feculent
 Matter.
   In the  Caecum, and  beginning of the Colon, the Food
 coming from the Ilium is retained tor some time, and, in
 consequence <4" absorption, acquires a greater degree of
 consistency, and receives a foetid smell.
   'The Valvula Coli, sometimes  called  Valvula  Her,  or
 1'iL'vula  U.uiomsi, tiom  its supposed-discoverer, and
 FVi/vii/a'Tui-pii from  tbe Author who  gives a particular
 description of it', is situated at the beginning of die Colon,
 and is placed  -ansverscly in the posterior and left part of
 t*iat Intestine.
   It is formed of a projection of the Villous and Nervous
 coats, and Circular Muscular Fibres ofthe Ilium, Csecuni
 and Colon  and has two Folds or Lips, with an apertur;
 in form of a Mouth or Chick between  them.
   At tbe ends of the Valves are two cords, termed Red-
 nacu.a Or Frena Mowami, which retain the Valve  in
 its proper situation.          /
   The Valve of the Colon allows a free passage for the
 C'mr.ents ofthe Small into the Large Intestines, but com-
, phtrly prevents their return.
   'The Colon is a similar structure with the Ciecum.—The
 Longitudinal  Muscular Fibres are collected upon it into
 three Fasciculi or  Bands, which arise at the root of the
 Vermiform Process, and are continued along the  Colon
 to the Rectum.
   The Longitudinal  Bands are shorter than the inner
 parts ofthe Colon, and of consequence assist in contract-
 ing it, and  forming it into Plicae, whicli lie across the
 Gut a  ......":",rtnth" V'lvul-.cConniventes; only they are 
128
at a greater distance from each other, and much larger,
dividing the Colon into little apartments, cailed Cells.
  The Cells ofthe Colon, with their Partitions,  have a
threefold order, the Intestine being almost quite smooth
or plain, opposite to the Longitudinal Baiyfs.
  The Cells assist in preventing the too quick descent of
the Fxces.
  The use of the Colon  is,—to receive the Excrementi4
tious parts ofthe Aliment,—to retain them,—to chaiigev
them  into Faces, and then,by the peristaltic motion of
the Intestines and power of Respiration, to push them,
by slow degrees to the Rectum.
  The Rectum differs from the Colon in being covered
only anteriorly and laterally  by the Peritoneum:—Its
Muscular Fibres are stronger and  thicker, and spread
uniformly over the Intestine.—The Circular Fibres an
so thick at the end ofthe Rectum, as to have been nam

i
ed internal Sphincter.
  It has no Cells like the  Colon; hut the Cellular and q
Inner coat are so much larger here than they are higher
up, as to fall  into transverse folds, which, however, dis-
appear in proportion to the distension of the Intestine.
  The middle and under  end of  the Rectum has nume-
rous large Mucous Glands or Follicles.
  'The extremity  of the rectum forms  a firm Circle,
which acts as £ Valve, and  assists the proper Sphincter
in preventing the involuntary discharge of the Faxes.
  The Verge ofthe Anus is surrounded with deep  Folli
cles, the  contents of which prevent the tender  Skin of
the Anus from being excoriated by hard or acrid Faxes.
   'The Anus is also surrounded with a great deal of Fat, ■>■!
which admits of thednatation of the Rectum, and facili-J
tates the discharge  of the Farces.
  Tbe Rectum receives  the Faxes from the Colon, re-
tains  them for a certain  time, till, by  their weight and
acrid  nature, it is stimulated to discharge them :  which
it does by the power of its Muscular coat, and of the Le-
vator Ani. assisted by the action, of  the Diaphragmatic
and Abdominal Muscles.                   > *
  The Blood-vessels ofthe Intestines are large and nume-
rous,  and are derived from different sources.
   The Duodenum receives  branches  from  the  Splenic
and Hepatic Arteries. 
129
  The Jejunum. Ilium, and right half of the Colon, are
Wpplied by the Superior Mesentric Artery ; and the left
ialf of the Colon with the Rectum, by the Inferior Me-
jcnt ic Artery.
  The Veins of all  the Intestines send their Blood to
the Vena Porta:.
  3'he Absorbents of the Intestines are large and  nume-
rous__They arise from the Inner Surface of  the Intes-
tines, run in the Mesentery  and Meso-colon, passing
through their numerous  Glands —The  Absorbents  of
the Small Intestines  terminate in the receptacle  of the
Chyle ; those of the Large Intestines, which are smal-
ler than the former, go partly to the Thoracic  Duct, and
partlv to the Lymphatics ofthe Loins.
   Tlie Nerves ofthe Intestines are small, bnt  numerous,
and are derived partly  from the  Eighth Pair, but chief-
ly from the Great Sympathetics.
   The Vessels and Nerves of the Omenta are Branches
of those which  supply the Stomach, and have the name
it- Gastro-Epiploic,
                    LIVER.


  The Liver is a large solid Mass. of  a dusky  red co-
lour  situated immediately under the  Diaphragm, ex-
tending downwards to the margin of the Thorax, but
not going beyond it.                             _
  It  is placed  par ty in the  Right  Hypochondnurrt,
which it in a great measure fills, and partly  in the Epi-
gastrium, reaching over a little way into the  Left Hy-
pochondritim.
  It  is convex and very smooth on  the upper Surface,
where it is opposed to the Diaphragm, though  a little
flattened on the upper part of its left side, where it  is
placed opposite to the Heart.
   It is i>><\ -'-arly concave on  the  under  side, where  it 
                       130

rests upon the  Stomach and Intestines, and is perfora.
ted by several large Blood-vessels.
  It is thick on its right and posterior part, and becomea'J
gradually thinner  towards the left side ; it is obtuse or
blunt on its posterior, and acute or sharp on its anterior
edge,—and considerably  broader  from one side  to th«
Other than from before backwards.
  It is divided into Prominences or Lobes, two of whicf
called Great and  Small, or Right and Left Lobes, are
considerable as to form the Body and whole\ipper pa
ofthe Liver.—The others are small, and are  placed u|j
on the under side of the former.
  The Great Lobe is placed obliquely in  the  Right Hy»
pochondriac Region, following the Curve of the  Dia-
phragm, and rests upon the Pylorus, Colon,  and topi
the Right Kidney.
  The Small Lobe, distinguished from the Great  one
a broad Ligament, is placed almost horizontally, cbi1
ly in the Hepeastic,  and reaching only a little way inl
the Hypochondriac Region.

              —The other Lobes are,—
  The Lobules  Spigelii, which is  small when compared.
with the two former Lobes, but is the  principal one be-
low.
  It is situated near the Spine, upon the left  side of thj
Great Lobe, and is df z. Pyramidal form, projecting hli
a Nipple, as the small'Curvatuie of the Stomach.
  The Lobulus Caudatus,  which is merely  the root,
one of the angles of tie Lobulus Spigelii,  advanci
towards  the  middle of  tbe  lower s.de of  the Great^
Lobe.                                              n
  The Lobulus  Anonymus, or ^iiadratus, which is placefl
between the passage of  the  round Ligament and the i
Gall-bladder, and is less  prominent,  but broader  than'
the former Lobule.                                 a
  From the Lobulus Anonymus a bridge called  Pont\
or Isthumus. Hepatis, runs  across  tbe  Passage for the«
round Ligament, to  be joined to  the Left Lobe  ;—It is
sometimes a wanting.
  Upon the under side  ofthe  Liver, there are  several
Fissures, of which the following are the principal.
  The Great Fissure, called Fossa Umbilicials, between 
131
the right and  Left Lobes,  at the under and  fore-part
of the Liver.
   This  is terminated by a Notch at the fore-part Of the
Liver,—of different depths in different bodies,—and be-
hind, it is commonly covered with the  Bridge above-
mentioned.
   'The  Principal  Fissure.lermed  Sulcus  Transversus  or
Sinus Purtarum, extending from  the  right to the left,
between the Great and small Lobes, and bounded by
these Lobes at its extremities, and by the Lobulus An-
onymus before, and/by the Lobulus Spigelii behind, the
two latter forming parts compared by the Ancients to a
Gate, and therefore cabled Porta.
   The  Depression between the Great Lobe and  Lobulus
Spigelii, for the  passage  of the Inferior Vena Cava,
which has frequently a bridge over it, forming it into a
Canal.
   A Small  Depression called Fossa Ductus Venosi,  be-
tween the Left Lobe and Lobulus Spigelii, running  a
little obliquely  from right to left side, and receiving  a
Ligament,—which is a Branch of the Umbilical Vein in
the Pectus.
   The Liver is connected to the  Body by different Pro-
cesses, termed its Ligaments,  all of which, excepting one
are formed by doublings ofthe Peritoneum, viz.
   The  Ligamentum  Latum, or  Suspensorium  Hepatis,
placed between tbe right and  left Lobes above, and
extending below  into the Fossa Umbilicalis.
   It is fixed obliquely to the Diaphragm and tip>of the
Enisform  Cartilage, and then descends  in the same ob-
lique direction,  adhering to the inner part Of the Vagina
of the  Right Rectus. Abdominis Muscle, as far as  the
Umbilicus.
   The  Ligamentum Rotundum,—which is the  Umbilical
Vein in the Fcetus placed in a doubling at  the under
pait ofthe  Ligamentum Latum, and fixed to the Um-
bilicus.
   These two Ligaments  have been supposed to resem-
ble a Falx, with the edge  turned uppermost, from which
circumstance the Ligamentum Latum is sometimes also
called Fiilcijlr me.
   The  Ligamentum Ihn'r-tw, or  Right  Lateral  Li$a- 
CW»fl|
                        132

wient, which is short, and connects the back-part of the
right extremity of the Great Lobe to the Diaphragm.
  The Ligamentum Sinistrum,  or Left Lateral Liga-
ment, which is longer than the former, and connects the
left extremity ofthe Small Lobe to the Diaphragm.
  The L-gamentum  Coronarium,  considered by some as
merely Cellular  Substance, by  others as  a reflectioa*
of the Peritoneum, or both.—It unites the  root of th»
Liver to the Tendinous Portion of the Diaphragm.
  Besides the Ligaments already mentioned, two otli
are described by Hali.eu ;  one called Hepatico colicuni^
which passes from the Gall-bladder  and contiguous
Sinus Portarum^ across the Duodenum,  to the Colon;
another called Hepatico-renale, which descends from the
root of the Liver to the Kidney.—'These as well as ft*
other Ligaments  of the Liver in general, are product
rions of the Peritoneum.
  The Ligaments of  the Liver preserve it in its prol
situation and of course  prevent it  from inclining  t\
much in  any direction.   The  Stomach and Intestine
support it when the Body is upright, and the Diaphragm
when the Body is inverted.
  'The Liv«r  has  a simple coat adhering closely to !t
which it derives  from  the Peritoneum,  and is ever/
where covered by this  Membrane, excepting behind,
where it adheres to the Diaphragm by Cellular  Sub.
stance.
   The Substance of the Liver is composed of seveaf
kinds of Vessels, the  extreme Branches of which are »•
termixed in such a manner, as to form numberless Puf.
py Corpuscles, named Acini, from a resemblance to smaB*
Stones or  Kernels  of Fruit, which  when minutely ex-
amined, are observed to be composed of Vessels in the-
form of radiated Villi or Penicilli
   The Vessels ofthe  Liver are, the Hepatie'Artery, Vena
Portanum, Vena Hepatic*, Absorbents, and Biliary Ducts.-
It has likewise numerous Nerves.
   The trunks, of the Hepatic Artery, Vena Portx, Bili-
ary Ducts and Nerves, with the Absorbents and Lypha-
tic Glands of the Liver, form a large  Cord at its under
part.
   The Artery is situated in the left part ofthe Cord, tr
Vein in the right, with  the  uunk of the Bil'ar»' Ducts 
before it;—the Nerves and Lymphatics surrounding the
great Vessels.
  The Cord of Vessels and Nerves is intermixed with
much Cellular Substance and covered externally by a re-
flection ofthe Peritoneum, which has obtained the name
of Capsule of G L i ss o n.
  The Branches of Vessels and Nerves accompany each
other through the substance of the Liver, forming small
Fasciculi, in a manner somewha: similar to that by which
the Cord is formed by thei> Trunks.
   In their course through the Liver, the Branches of
 the different Vessels and Nerves,  but particularly those
 of the  Vena Portx, are inclosed in a large portion of
 Cellular Substance, which is also frequently called Cap-
 sule u/Gi.isson.  from  that Author supposing it to  be a
 continuation of the Capsule which covers the Vessels
 before they enter the Liver.
   The Hepatic Artery is derived from the Caeliac, and is
dispersed throughout the whole substance of the Liver,
 and also upon the Coat which covers it, and is so small
 when compared with the bulk of the Liver, as to have
 been generally supposed to be destined for the nourish.
 ment merely of that Viscus ; but  from injections  pass-
 ing from the Artery to the Biliary Ducts, and from other
 causes, it has been supposed by  some Anatomists, that
 the  Hepatic Artery is not only intended  to nourish the
 Liver,  but is capable of secreting part cf tlie Bile ;—and
 this  supposition  is  f.rlher confirmed from  the  Vena
 Ponx having, in a recent case  been found a wanting,
 while at the same time  the Hepatic Artery  was larger
 than usual, and  the  Veins which commonly form the
 Vena Portae. terminated in the Vena Cava.
   The Vena Porta is named  from  its situation with re-
 spect to the Porta of the Liver.
   It partakes ofthe nature of an Artery and a Vein:—
 Like the former  it carries the Blopd from the Trunk to
 the  Branches, and; like the latter, it carries it to the
 Heart; or it is peculiar in the Blood, in one part flowing
 from the Branches to  the Trunk, and in another from
 the 'Trunk to the Branches.
    It is formed by the Veins of the Stomach  and Intes-
 tines, joined to those of the Spleen, Omentum, and Pan-
      VOL. II.              I 
134
 creas, and approaches to the nature of an  Artery in the
 thickness of its coats, though it has no pulsation.
   It passes to the Porta, where from its great size, it
 is named Sinus  of the Vena  Ports, and divides into
 Branches which accompany those of the Artery in  their
 course through the substance of the Liver, terminating
 at the last in the Pulpy Corpuscles.
   The Vena Porta serves to carry Venous  Blood to the
 Liver, for the secretion of the Bile.
   The Vena  Hepatic* are numerous.  They are reflec-
 ted partly from the extremities ofthe  Artery, and part-j
 ly from those of the  Vena Portx. They unite by dc-;
 grees,  and accompany the other two sets of Vessels;
 but at the root of trie Liver they form two or three large
 Trunks which Terminate in the  Vena Cava, where it is
 abou: to perforate the Diaphragm.-1—They likewise send
 oft' some small Branches which terminate  in the Cava,'
 where that Vein lies behind the Liver.              m
   The Venx Hepatica; receive  the Blood from the H^
 patic  Artery  and Vena  Ports  after the  Bile has  been
 secreted, and return it to the Vena Cava, to be  convey-'
 ed by it to  the Heart.
   The Lymphatics of the  Liver are so numerous as to
 cover almost the whole of its outer Surface.   'They dis-
 charge their contents,  partly into  the beginning of the
 Thoracic Duct, and partly to a Plexus situated in the ■
 fore-part of the 'Thorax.
   The Nerves of the Liver are also numerous.  Thfy
 arise from the Great Symputhetics and Eighth Pair, aid
 accompany the Blood-vessels.
   The Biliary Ducts arise by extremely minute Brandi-
 es,  termed  Pori  Bilarii or Tubuli  Bilifcri, chiefly from
 the extremities of the Vena Porta*, in the  Substance of
 the Corpuscles, through the whole ofthe Liver.
   The  Pori Bilarii run in company with the Branches
 of tbe  Artery and  Veins,  and unite into larger and  lar-
'ger Branches, which afterwards go into two, and the#
 again into a single Truuk in the Sinus Portarum, called -
 Ductus  Hepaticus.
   The Ductus Hepaticus serves to carry the Gall or Bile
 which is of  a yellow green colour, from the Liver,—and
 to convey it by the power of the Heart, Hepatic Artery^
 and Vena Porta:, assisted by the  pressure of the sur- 
 rounding  Muscles, to the Duodenum, and partly to the
 Vesicula Fellis.
   The  Vesicula,  or  Cystis Fellis,  or Gall-bladder, is  a
 small oblongPyriform Bag, consisting of a Bottom, Body
 and Neck, situated  upon the concave side ofthe Great
 Lobe of the Liver,  and  placed in a transverse direction
 from behind forwards.
   It extends from the Sinus Portarum;  where the Neck
 is situated, to the anterior edge ofthe Liver, and when
 full advances beyond tbe edge ofthe Liver, so as some-
 times to have its Fundus'opposed to the soft parts of
 the Abdomen under the edge ofthe False Rib's,
   The  bottom is a little lower than the Neck, when the
 Both is in the erect  posture.  It inclines also a little to
 the right side, and  rests upon the Colon at the begin-
 ning of the Duodenum.
    It is composed of fereral coats, the external of which
  is  a continuation of the  Membrane of the Liver :  This
  however, is onlv a partial coat covering that part cf the
  Gall-bladder, which projects beyond the Surface of the
  Liver.__It serves to give strength to the  Gall-bladder,
  and to fix it to the Liver
     Under the former Coat, a few pale scattered Fibres,
  running  in various  directions, are sometimes observed,
  which have been considered as a  Muscular Coat ,• under
  this is  a small quantity of Cellular Substance', which has
  obtained the name of Nervous  Coat.
     The Inner Coat, sometimes  called  Villous, is full  of
  small Reticular Ruga* or folds, which become extremely
  minute towards the Cervex, where they rim in  a longi-
  tudinal direction.
     The Surface of this coat is every where perforated by
   the ducts of small  Follicles, which  discharge  a viscid
   Mbciis to defend the Surface of the Inner coat from the
   Stimulant nature of the Bile. ,
   JThe  Gall-bladder  is connected  through  its whole
  length to the Liver by Cellular  Substance, Blood-ves-
  sels, and Absorbents,  among which  the  Hepato-cystic
  Duct,  similar to those found in many Animals, were in
  former times described, and supposed to carry the Bile
\ found in the Gall-bladder immediately  from the Liver.
t* It is now sufficiently  ascertained,—that no such Ducts
[ exist  in the human  body. 
136
  The Gall-bladder has Blood vessels, Absorbents, and
Nerves, common with those of the Liver.—Its Veins pass
into "the Vena Porta*
  The Neck of the Gall bladder is  twisted and folded.
against itself, and afterwards contracts and sends out a
Duct called Cysticus which runs near the Ductus  Hepa-
ticus, and then joins  it,  to  form the Ductus Communis
Cboleaochus.
  The Ductus Cisticus is smaller than the Ductus  Hepa.
ticus, and differs from it also in  having a number of ira*
perfect Partitions or Plica, running in a somewhat spiral
direction, and  forming it into  Cells which retard the
flow of the Bile.
  The Gall bladder serves as a receptacle for the Bile,
when the Stomach and Intestines  are empty and have
no need of it,'and retains it till  wanted for the  purpose
of digestion.   It is afterwards discharged from the Gajl-  j
bladder, when the Stomach is full into the Ductus Coij^M
munis, and from  that to the Duodenum, chiefly by ttfQM
pressure of the surrounding Viscera, and partly as some   |
Anatomists suppose, by a contractile power in the Gall-   1
bladder itself.  The whole of the Bile contained in the
Gall-bladder is found by experiment to pass, frort the
Liver through the Hepatic Duct to the Ductus  Cora-
munis, and from that by the Cystic Duct into the Gall-
bladder.
  The Bile returning from the  Gall-bladder is observed
from the thinner parts  being  absorbed, to be thickflH...
more acrid and bitter, and of a deeper colour, than thtf  ,\
which flows from the Liver                          \.
  The  Ductus communis Choledochus-, called  Cboledocbuf*
from its conveying Bile, is about  the size of a Gooie-
 quill, and is considerably larger than either ofthe  Ducts, i
 which open into it                                  •
   It descends at ^he posterior and left part of the Duo-  ,
 denum,  and passes for some way obliquely between the
 Muscular and inner coats of that Gut,—the obliquity an-.
 swering the purpose of a Valve.                         I
    It termi ates  in the  left, posterior,  and near to the
 under part  of the second Turn of the Intestine, by  a
 projecting Orifice, which is rounded above, and pointed '
 below.
    The Structure ofthe Ductus Choledochus. and ofthe
 Biliary  Ducts in  ceneral. is ofthe sam* nature, being 
entirely Membraneous : The  Inner Surface of the Ducts
also agree in being perforated by numberless pores, which
are the Mouths of Mucous Follicles, similar to those upon
the inside ofthe Gall-bladder.
  The Bile  serves to  mix the different parts of the Food
properly together,  for the formation of the Chyle,—to cor-
rect too great a disposition to acidity,—and  to excite the
Peristaltic motion  of the Intestines.

                      SPLEEN.
  Thk Spleen is a soft and very Vascular Substance, and
of a purple  colour.
   It is somewhat depressed,  is  of  a  long oval form, and
of considerable size, but varying in this respect in differ-
ent subjects.
  It is situated in  the  Left  Hypochondriac Region, be-
tween the  large extremity of  the Stomach and  corres-
ponding False Ribs;—Its  under end lying behind tbe
Colon, and over the top ofthe Left  Kidney.
  The  situation  of the Spleen  varies a little, according
to tlie state  of Respiration,  and to  the fullness <r  empti-
ness  of the Stomach ;—rising  or  falling as  the  Lungs
are less or  more  dilated,  and  becoming more oblique in
its  situation,—with its  inferior extremity  turned  more
i awards, in proportion as  the Stomach  becomes more
distended.
  Its External Surface is convex and uniform, like that
ofthe Ribs, &c. to which it is opposed.
  Its Internal Surface, or that next the Spine, is  irregu-
larly concave; and is  divided  into an Anterior and Pos-
terior Plane, by a  longitudinal  Groove or Fissure, where
the Vessels and Nerves enter.
  The Anterior Plane is more  concave than the Poste-
rior,  corresponding  to the contiguous  convexity of tbe
Stomach.
  The  Spleen  has  frequently  deop Fissures upon  its
edges ;—sometimes ft has small Appendages attached to it,
and not unfrequently  there  is  one or more Small Spleens
connected with it.
  At the under side, it is fixed to the Omentum, and, by
means of  that  and  Blood-vessels,  to the  Stomach  and
Pancreas.—Behind, it is connected  to  the  Diaphragm ;
                         i2 
138
oniKI
 iu^J
>e^B
and below, to the Left Kidney and  Colon, by reflections
ofthe Peritoneum, and  by  Cellular Substance.
   It is covered  by a  double Membrane,  one Layer of
which is a production of the Peritoneum,  the other pro-
per to the Spleen itself; but  so  closely connected to the
common coat, that they  appear to be one and the same
Membrane.
   The substance of  the Spleen  is remarkably soft, and
is by much the most tender ofthe Abdominal Viscera. ,
   It consists of a Congeries  of  Blood-vessels, Lyrnphai^
tics, and Nerves, joined  together  and  supported by 2
large quantity of Cellular Substance.
   The extreme Branches of  the  Blood-vessels put on the
appearance of Penictli, or small Briishes, which have beea
mistaken for Glands.
   These vessels are* so  tender^ that  when an injection IK*
forcibly thrown  into either ^ir ery or  Vein, it bursts
the common Cellular  Substance,  and  gives the  apj
ance of Follicles or Cells.
   The Blood-vessels, of the Spleen are among the largest
of the Body,  in proportion  to the Viscus on which they   j
are dispersed.
   The Artery is  a principal Branch of the Caeliac.—It runs
in a serpentine direction, and, after sending Branches to  j
the Pancreas, &c. and  the -Arteri* Breves to the left end  j
ofthe Stomach, it goes  into the  substance of the Spleen,
where it is subdivided into  Branches,  which are  crowded
together,  and run in ev ry  direction,  forming at lengtk
Plexus  and  Peniciili, which terminate in the Branched of
the corresponding Vein.                                i ,
   The Vein, like that in most other Viscera, is larger thaf.*V.
the Artery : It receives the  Blood immediately  from the
terminations  of the  Artery, without the intervention of
Cells.              ,                                   j
   The Splenic Vein receives  the  Vena Breves of the Stom-
ach, the Pancreatic Veins,  &.c and lorms one of the prin-
cipal Branches of the Vena Portx.  ,
   The  lymphatics  from  the superficial   parts  of the
Spleen  join  the deep seated Absorbents at the Fissure
where  tlie  Blood-vessels  enter, and  afterwards  past
through several  Conglobate Glands lying over the Splenic
Aieery. 
1'39
  They intermix with  Lymphatics belonging to sever?, i
Other Viscera, and terminate in the Thoracic Duct
  The Nerves of iV>c Spleen, which are smaM, but consi-
derable in number, are Branches of the Great Sympathetic
and Eighth Pair, and form an irregular Plexus which sur-
rounds the Vesseli.
  No Excretory  Duct has been  found  to proceed from
the Spleen, in consequence of which very various opinions
have been entertained with respect to  the use of that
Organ.
 'Many of -the Ancients were of opinion,—that besides
the Bile of the  Liver there was  an Atra Bilis, or Black
Bile and that the Spleen was the receptacle  of the lat-
ter.                                    „  .          -
  Others nave thought a particular Menstruum  was  secret-
ed in it, and conveyed  to  the Siomach for the purpose of
digestion.
  Others again,—that  the Blood  of  the Spleen promotes
the sluggish circulation of Blood of the Vena Portae.
   The late Mr. Hewson,  who has  written  particularly
on the Spleen, was of opinion it concurred with the Thy-
mus and Lymphatic Glands, in f rming the red Globules
of the blood,  and that these globules were rendered com-
plete in the Spleen.
  It has been  also supposed,—that  as the Stomach be-
comes full, the Spleen is compressed by it, in consequence
of whicli a greater quantity  of Blood is sent to the Pan-
creas, for the Secretion ofthe Pancreatic Juice.
  But the present most prevalent opinion is,—that the
Blood undergoes some change in it, which renders it use-
ful in the secretion of the  Bile; and the  opinion  is sup-
ported from the great quantity  of Blood with which this
Organ is known to be supplied, and  from its Vein, not
only  in Man, but in other  anjmals, passing to  the  Vena
Porix.
                    PANCREAS.
  The Pancreas, i. e. All Flesh, or the Sweat  Bread, is a
long flat Giand of tbe Conglomerate kind, and  of the
same nature with the Salivary  Glands,  of which it may
be reckoned the largest.
  It  is situated in the Epigastric Region,, and placed trans-
versely in the bac^-part of the Abdomen, between the
Stomach and Spine. 
140
   It has a large or Right Extremity, and a small or Left
one, an Anterior and posterior Surface, and an Upper and
Under Edge.
   The  Right  extremity,  is attached to the left side of
the second Turn of the Duodenum, or to that part where
tbe Intestine is about to go across the spine.
   From the under part of rhe Right Extremity,  the Pan-
creas sends down  an Elongation or  Process, which ad-
heres closely  to the Duodenum.
   This process was discovered by Winslow, and  terma '
by  h  m Pancreas  Minus.—It is  also called Head of tit
Pancreas.  ■
  Tbe body  ofthe Pancreas passes before the upper part
of the tiansverse portion of the Duodenum,  and over the
A-Tta. Vena  Cava, and part of the Splenic Vessels, to alt I
of which it is attached.  •                               I
  The small  extremity,  which  is  rounded,  fixed to the 1
Spleen, through the medium of the large  Omentum.   »   1
   I he Pancreas is covered anteriorly by the two LavRJ^J
of the root   of  the  Meso-colon ;— posteriorly,  it  is urJ^H
covered with  Cellular Substance,  which connects it to the I
Vertebra.                                              1
  It is composed of Acini, which  form small Glands or 1
Lobes ; and these  are connected loosely  by  Cellular Sub- I
stance, in inch a manner as to give an appearance of uni-, I
form':t> and smoothness to  the External Surface.          'M
  The Arteries  of tlie Pancreas are  derived, partly from-'M
the Hepatic,  but chiefly from  the Splenic, by several small/a
Branches, which pass at various places into its SubstancdflH
in a transverse direction.                               ™
  The Veins correspond in  name and  course with the  At-1, A
teries, r.r.u assist in forming the Vena Ports.             V
  Tht Lymphatics run to the Splenic Plexus, and termi- 1
nate in the Thoracic Duct.
  Tb  Nerves of the Panc^as are small: Like those of J
the other Viscera of the. Abdomen, they  are derived from m
the f.reat Sympathetic and  Eighth Pair.                 *~
  From '.be different Acini of the  Pancreas small Ducts
arise..which join into larger ones running transversely in
the Substance of the Pancreas,  and  forming a common
Duct, ditto Ducc-:s Pancreaticus..
  The Pancreatic Duct, termed also Ductus  \\ irtsunci 
141
after the discoverer of  it in the  Human Body, is remar-
kably thin, of a white colour  and seTii-transparenr.
  It begins  at  the left Extremity of -he  Pancreas, runs
in the  substance  of the Gland,  a  little below its middle
heighth, and becomes  gradually larger  in consequence
of receiving  the  different  Branches which cornpobe it,—
and Is at last about the size of a Raven's-quill.
  At the  Right  Extremity  of the  Pancreas,  it receive*
the Principal Duct of the Pancreas  Minus, and  termin-
ates oblquely in the Duodenum along with the  Ductus
Communis Choledochus.—In seme  rare  cases, however,
it terminates at  a little distance from the Biliary Duct;
and sometimes  also, the  Duct  of the  Pancreas Minus
ends separately in the Duodenum.
  The Pancreas  secrets a Liquid  or Juice, resembling
SaJiva in quality  and appearance,  and  discharges it by
its Excretory Duct into the Duodenum.
  The  Pancreatic Juice incorporates the  Bile  with  the
Alimentary Mass, and  may be said also to answer the
same purpose to the contents of the Intestines, which the
Gastric Juice docs to those ofthe Stomach ;—or, it finishes
that digestive Process in the Intestines which was begun
in the Stomach. 
ORGANS  OF URINE  AND  GENE-
                  RATION.

                IN THE  MALE.
                     KIDNEYS.

   Tut. Kidneys are two  Glandular  bodies, of a pale red
colour, situated in the upper and back part ofthe Abdo-
men, in the Lumbar Region.
   They are placed one or each side of the Spine extewf-
jng from  the Eleventh Pair of Ribs to near the Ossa Ilii-
and rest upon the Diaphragm, large Psoae, Quad rati Lum-
borum, and Transversales Abdominis Muscles.
   The Right Kidney is situated  at  the  under and back-
part of the large Lobe of the Liver,  behind the Colon, and
is commonly very little lower than the left.
   The Left Kidney is situated at the under and back-parfj
of the Spleen, and behind the left parts of the Stomach,
Pancreas, and Colon.                     ,
   The Kidney is abour five or six-fingers-breadth in lengi_
but considerably less from the outer  to the inner fide, am
less than that still from  before backwards; or, it is corwh
pared in shape to nE'rench or Kidney Bean.
   It is rounded anteriorly, flattened posteriorly, ccnvejfp'
and uniform at  its outer margin, and has a deep depre-
sion  or  Sinus towards the Vertebrae,  surrounded with
unequal edges, where  the  Renal  Vessels and  NerveSjj
enter.
   It is a  little broader  behind than  before,  and a little
broader and more curved  above than below, from whiclf
circumstance, but  more particularly from the disposition of
the Vessels to be  afterwards mentioned,  it is easy to dis-
tinguish the Right from the  Left Kidney when taken cut
of the Body. 
H3
   The Right KiJney is connected to the Liver and Duo-
 denum, the Left to the Spleen, and  both to the Muscles
 on  which  they are  placed  and  to  the Renal Glands
 and  Colon, by  Cellular Substance  and l»y the Perito-
 neum.
   They are also connected to .the Aorta and Vena Cava
 by the   Blood-vessels, and  to the Bladder  of Urine by
 the Ureters.—They accompany the motions of the Liver
 and Spleen, in the different states of Respiration.
   Each kidney is surrounded  by loose Cellular Substance,
 whicli  commonly contains a considerable  quantity of Fat,
 from which it is termed Tunica Adiposa.
   The  Tunica  Adiposa  covers  not only  the Kidney,  but
 large Vessels, and defends them from  the pressure of  the
 Surrounding Viscera.
   Under the Tunica Adiposa, there is a Membrane com-
 posed of the original proper Coat  and Cellular Substance
 incorporated, which adheres close to  the Kidney, and is
 retlected over the edges of the Sinus,  to be  joined to  the
 Pelvis and large Vessels*
   The  substance of the Kidney is commonly smooth and
 uniform, though sometimes it is irregular, in consequence
 of the  Lobes which originately from   it  not  being com-
 pletely  incorporated.—Ic consists of an  outer part called
 Cortical, and an inner termed  Medulary.
   The Cortical Substance, termed also Secerning, surrounds
 the Ividney, and forms  about a  third of its  breadth ;—it
 likewise sends in Processes or Partitions, which separate
 the Medulary parts  from each  other.
   The  Medulary termed  also Uriniferous Substance,  is of
 a redder colour tnan  the former, and is divided into a num-
 ber of distinct Columns  each of  whicli terminates in 4
 projection caled Papilla, or Processus Mammillaris.
   The Papilla merely  the continuation ofthe Uriniferous
part;  tiougri frequently  considered as a third division of
the substance of the  Kidney.
   Each   Kidney has one, and sometimes more A-teries,
winch run transversely from  the Aorta, and  a Vein still
larger, which terminates in the Cava.—They enter at the
Siiiu-. of the Ki i..ey,  and  are  included in Cellular  Sub-
stance, which accompanies them throughout tleir course
   The Right Renal  Artery is longer than the  Left in con- 
144
sequence ofthe Vena Cava, behind which it passes, being
placed upon the Right Side ofthe Aorta.
   The Artery as it  approaches  the Kidney,  is divided
into Branches,  which are afterwards minutely distributed
through the Cortical Substance, forming Arches and. An.
astomoses;—but these ait found to be much less freqwii,
than are commonly described.                         *■
   The small Branches, after turning and winding in vaii.
ous directions, pass partly towards the Surface of the K$ M
ney, where they form irregular Stars, some of which sup. 7
ply the proper membrane.              v
   Others turn  inwards in  a  waving direction, and form
Carpuseles,  which are disposed  somewhat after the man-
ner of Clusters of small  Berries,  which  can only be atui>
distinctly by the assistance of  Glasses,  after a  minutwp'!
jection.                                            >i
   The Corpuscles were considered by  Dr. Nicholasm
the Globular termination  of Blood-vessels, and termeJR* I
him Globuli Arteriarum Termini,-—but  these Clobuli wfltll
afterwards observed  by Mr. Hewson to consist of small
vessels intimately intermixed.
   The Veins returning from the  extremities of the Arte-
ries unite in the Cortical  Substance of the Kidney.
   The Branches of  the  Renal Vein  are much larger than
those of the Artery,  but  correspond  with them in their
course.—They  form  a large Trunk  on each side, whicli
lies anterior to  the corresponding Artery, and runs traM-
versely to the Cava;—the  left, which-is the larger of 0
two, passing across the fore-part of the Aorta.       &
   The Lymphatics  of tbe Kidney run from without M-
wards,  and terminate in the   Lumbar  Glands, and after-
wards in the Thoracic Duct.—The  Superficial  Lympha-
tics are so small, as seldom to be seen,  excepting in the
diseased state of the  Kidney.                            m
   The  Nerves are  from the Semilunar Ganglion formed^
by the great  Sympathetic and Eighth Pair.  They form
a Plexus which surrounds the Blood-vessels, and accom-^
panies them in the Kidney.
   From the minute  Extremities *f the Renal Artery, in
the Corpuscles seated in the Cortical Substance, the Uri»'t
iferous Tubes arise.   They are mixed- with some extremely
small  Blood-vessels, and  constitute the  Medullary Sub-
stance of the Kidney, 
                          145

   By degrees they unite into larger  Tubes, which ran in
a  radiated  manner, the direction being from the outer
edge or circumference,  towards the  inner part or Cavity
vf the Kidney.
   Thayradiated Tubes,  becoming still larger in their pas-
sage terminate in the Papilla, which are of a  compressed
conical form, and are at a little distance from each other.
   The Papilla are  twelve  or mo«e in each Kidney, the
number varying according to that of  the  original Lobes
of which the  Kidney  is composed, and  likewise  from
some of the Papillae  being incorporated with each other.
   Upon the points of the Papillae are  the termination of
the Uriniferous Tube,—large enough  to be distinguished
by the naked Eye,—through which the  Urine distils  frOra
 the Substance ofthe Kidney.
   Round  the  root of each Papillae, a Membrane Tube
arises, termed Infundibulum or CaJix, which receives the
Urine from the Papillae.
   Tbe Infundibula are commonly the same in number  with
the Papilla;; the number,  however,  varying  in different
subjects, two or more of the  Papillae sometimes  opening
into the same Infundibulum.
   The Infundibula joins into two or three  larger Trunks
which afterwards form a Dilatation  ot  considerable  size,
of the shape of an inward Cone, and termed pelvis of tha
Kidney.
   The Pelvis  is  placed partly within, but the  greatest
part of it  without the body of tbe Kidney, and contract!-,
into a long Tube, about  the size of  a writing-pen, called
Ureter.
  The Ureters are commonly one to  each Kidney, though
in some  rare  instances they are double on one  or  both
sides.
  The Artery of the Kidney is placed uppermost,— the
Vein in the middle and fore-part,—and the  Pelvis and be-
ginning of the Ureters  at the under and back-part of the
Blood-vessels.
  The Ureters descend obliquely inwards behind the  Pe-
ritoneum,  and go over the great Psoa:  Muscles and liiae
Vessels, opposite to  the anterior and lateral parts of the
Os Sacrum.
  They pass afterwards into the Pelvis, and terminate in
the under, outer, and back-part of the Bladder
       VOL. U.               K 
146
   In their descent, they are  not straight, but form turns,
 which are commonly compared to the Italic/,- neither are
 they cylindrical,  as they  form slight dilatations and con-
 tractions in their course,  two  of which contractions are
 more observable in their passage over the Psoas Muscles,
 and at their insertion into the Bladder.          '
   The Ureters are covered anteriorly  by the Peritoneum,
 and composed of an ESeternal Membranous  coat, a middle
 Muscular one, formed chiefly  of  circular Fibres, and u
 Internal coat, sometimes called Villous.
   The  Inner coat is very Vascular, and is perforated by
 the  Mouths ofthe small Ducts, which line it with a Mu-
 cus  toxlefend it from the Urine.
   The Vessels and Nerves of  the Ureters are from thoie
 of the contiguous parts.
   The use of the Kidneys is  to secrete the Urine from th#
 Blood, and convey it by means of the Ureters to the Blad-
 der.

                 RENAL ELANDS.                 v
                                                      ■**
   The Renal Glands,  termed also Capsulx Atrabilar'ucf
 Capsul*  Renales,  Renes Succenturiati, and Glandula Su-
prarenales, are two small, flat, Glandular-like bodies of a
 dark-yellow colour, lying  in  the  upper and back-part of
 the  Abdomen.
   They are situated at the upper,  inner, and  fore-part of
 the Kidneys, over the large Psoae Muscles and Diaphrajp
 and brighter than the Renal Vessels.                 *
   They are of an irregular figure, and are about a couple  ]
 of fingers-breadth in length, but much larger, proportion-  j
 ally, in the Foetus than in the Adult.                      j
   The Right one  is connected to the Liver, the Left to  |
 the Spleen and Pancreas, and both to the small Muscle otlJ
 the Diaphragm,  and to-the  Psose Muscles and Kidney*,*1
 by the Cellular Substance.  They are likewise retained 1
 by numerous Vessels and Nerves whicli are spread over  I
 them.
   They  are surrounded  by  Cellular Substance, which is
 part of the Tunica Adiposa  of the Kidneys,  and have  a
 thin proper coat which  adheres firmly to them.
   They are frequently observed to be hollow, and to con-
 tain a dark-coloured bilious-like matter, which is coasi- 
147
deretl by many Anatomists as the Internal, very Vascular
and tender parts melted down by putrefaction.
   'Their Arteries come from  th"ose  of the adjacent parts,
particularly from  the Renal,  and  also  from the Aorta,
and Diagrammatic Arteries.
^  Of ihe principal  Veins,  the  Right to the  Vena  Cava,
and the Left to the Renal  Vein.
   Tlie  Lymphatics go chiefly to those ofthe Kidneys.
   The  Nerves come principally from the Renal Plexus.
   They have no Excretory Ducts.
   Tlie   Renal Glands  have been supposed to furnish
 Lymph for the dilution ofthe Bipod returning in the Re-
 nal Veins, afer the secretion of the Urine;
   Or,__to restore to tbe Blood  of  the Vena Cava  the ir-
 ritable  pans which it loses  in the secretion of the Urine
 and Bile;                                           .
   Or,—to  convey  something  useful  to  the Thoracic
 Duct;
    Or,  in  the Foetus,—to divert the Blood from the Kid-
 neys, and thereby lessen the quantity of Urine.
    But  their use is still undiscovered; though it is suppos-
 ed from  their vicinity  to  the Kidneys, not  only in Man,
 but in  many other animals,  that  they  are suWservient to
 these Organs, and particularly to those of the Foetus.

                 VESICA URINARIA.

    The  Vesica Urinaria,  or Bladder of Urine,  is a large
 Sac situated in the Pelvis of the Abdomen,  in the  bottom
 ofthe  Hypogastric Region.
    It is placed in the fore-part  of the  Pelvis, behind the
 Ossa Pubis, and  before the upper, and above the under
 portion of the Intestinum  Rectum.
    When empty, it is contracted into  a small size,  which
 occupies tbe under and  fore-part of the Pelvis; but, when
 fully distended,  it  rises above the brim of that  Cavity,
 and  sometimes ascends  to within a little distance of the
 Umbilicus.
    When moderately dilated, it is  of a roundish, irregular
 oblong form, but a little flattened  before, more convex be-
 hind,  and  broader at its  anterior  and posterior, than to-
  wards its  lateral parts,—a  little  more  capacious, also,
  belotv than above, especially at its posterior part. 
148
    It is distinguished  into Fundus, Body, and  Cervix, the
 first of which is placed upwards and a little forwards;
 the last at the under and fore-part.
    It is connected below to the Rectum,  and at the sides
 to the Pelvis by the reflected Peritoneum and  Cellular
 Substance, the former  of which,  when the  Bladderis
 empty, has the appearance of lateral Ligaments.
   It is attached, at the fore-part of its Body, by  Cellular
 Substance, to the Ossa Pubis, without the intervention d
 the Peritoneum.
   It is also fixed  to  the  Umbilicus by three  Ligaments
 situated between the Peritoneum and'Abdominal Mus-
 cles.—They are formed of the Urachus running- upwardi
 from the Fundus,  and  the shrivelled Umbilical Arteries
 passing obliquely from the sides of the Bladder;
   The firmest connection is by means of a  Ligamentow
 expansion, which runs from  each side ofthe Neck of
 Bladder and Prostate  Gland,  to  be  fixed to the insid
 the  Arch of the Ossa Pubis.  It is connected, also,
 this place, to the Penis, by the Urethra.
   It is composed of different coats  joined together  by
 Cellular Substance, the first of which is only a partial one
 continued from the  Peritoneum,
   The  Peritoneal or common coat, recedes  from the Ab-
 dominal Muscles at the top of the Pubes, and passes over
 the superior,  and down upon the  posterior,  and laterii
 parts ofthe Bladder, to  neatr the termination ofthe Ure-
 ters, where it is about a fingers length from the Apu%-
 and is there reflected upon the Rectum and back part of
 the Pelvis.
   When the  Bladder is  much distended, it carries the
 Peritoneum  with  it, and  leaves  a  space  between that
 Membrane and the  Pubes, of such  length, that an inci-
 sion has frequently  been made  here, and large  Calculi ex-
 tracted  from  the Bladder, without penetrating into the
 Abdomen, or wounding the Peritoneum.
  The second  coat  is termed  Muscular.—It is corn
 of distinct Fleshy  Fibres, interwoven with each other,
and forming Fasciculi.
  The External Fibres run chiefly  in a  longitudinal di-
section, and are connected at  the under and fore-part of
 the Bladder, with the Ossa Pubis. 
149
  More internally, are Fibres  which run in all direction*^
and are intermixed with  each other in the form of Net-
work.
  The Muscular  Fibres are contracted about the Neck of
the Bladder, and  form what  has  been termed  Sphincter
Vesicx;—these, however, are  merely  the continuation of
the other Fibres.
  The Muscular  coat, by its contraction, occasions the
complete evacuation of the Bladder.—The Fibres about
the  Neck  of the Bladder, by acting separately from tbe
rest of  the  Muscular eoat,  prevent the involuntary dis-
charge of the Urine.
   The Cellular Substance, under the Muscular Fibres, is
frequently termed Nervous coat.
,   1'he inner coat, though  often called  Villous, is  smooth
like the inside of the  Peritoneum,  and, though thin, is
so dense as to prevent the exudation of the Urine.
   This coat is rendered somewhat unequal by the project-
 ing of the Fasciculi of the Muscular Fibres; and when the
 Bladder is empty, it forms large wrinkles or Rugae.
    The inside of  the  Bladder is very  irritable,  in conse-
 quence of which a desire  to expel the Urine is occasionally
 excited.  It  is lined,  however, by a Mucus,  discharged
 from its Arteries, which  prevents it from being constantly
 irritated by that  Fluid.
   The under part of  the Bladder is  perforated by  three
 Openings, of which one is placed anteriorly, and two pos-
 teriorly.
   The Anterior Opening is the beginning of the passage
called Urethra, and is surrounded by the Neck of the
Bladder.
   It comes off almost at a  Tight  angle from  the lower
part  of  the  Bladder, without any tapering of that Vis-
cus.
   The other two openings are formed by the termination
of the  Ureters,  which  run  obliquely  forwards and  in-
wards, between the  Muscular and  Inner  coat  of the
Bladder.
   They  terminate in  the  Bladder at a  little distance from
each other, and at the same distance behind the beginning
 of the Urethra, each  by a somewhat oval Opening, which
 is more contracted than the Ureter is immediately above it.
   The Arteries of the Bladder come from various  sources,
                          k 2 
but chiefly  from  tlie  Umbilical and  Pudenda Commu-
nis.
  The Veins return  to the  Internal Iliacs;—They form
a Plexus of considerable size upon each side of the  Blad-
der.
   The Lymphatics  accompany  the principal  Veins on
the Bladder, and, at the under part and sides, pass into
the Iliac  Glands.                                      (
  The Nerves are  Branches of the Great Sympathetic"
and Sacral Nerves.
  The Bladder  receives  the Urine from  the  Ureters by
drops, and sometimes by small thread-like streams or
squirts, tiil by its accumulated quantity and acrimony*  it
forces that Viscus to contract and expel it.
  The Urine is expelled, partly  by the contraction ofthe
Bladder itself, and partly by the  action of the  Abdom'mil
Muscles  and  Diaphragm pressing the Intestines agauifr>
the Bladder.
  The frequency of the evacuation  depends upon the
size and sensibility of  the  Bladder, upon the quantity of
Urine secreted, and the degree of acrimony it possesses.

                      TESTES.

  The Testes, formerly  termed Didymi or  Gemini, are
two Glandular Bodies situated in the Cavity of the Scro-
tum.
   The Scrotum,  which  furnishes an external  covering to
the Testes, is a continuation of the common Integument^
has the same  Structure  with the  Skin in general, but i*f..
more plentifully  supplied with Sebaceous Follicles, has no
fat in its  Cellular Substance, and  is occasionally relaxed fj
and   corrugated in a greater degree than the Skin  iri the
other parts of the Body.
   Upon the Surface  of the Scrotum, there is a superficial,
longitudinal  projecting Line, which divides  it into two
equal parts, and has  the name of Raphe.
  The inner Surface of  the Scrotum  is lined with Cellu-
lar Substance,  which is firmer and more Vascular than
in other places.
   The  Cellular  Substance  of the  Scrotum, in  conse-
quence of its redness,  Fibrous appearance, and supposed 
151
power of contraction,  has,  by many Anatomists, been
considered  as a  Muscle, and  called Dartos.—This opi-
nion, however, has of late years been rejected.
  The Cellular Substance of  the Scrotum involves each
Testicle singly, and forms a Septum or Partition between
the two,  which prevents Air or Water from  passing rea-
dily from one side of the Scrotum to the other.
  The Vessels ant Nerves of the Scrotum are chiefly from
those of the neighbouring parts.
  The  Blood-vessels are Branches of the  Pudenal and
Femoral.
   The Lymphatics go  mostly to the Inguinal,—but some
of them  accompany  those  of'  the  Testes to tbe Lumbar
Glands.
   The anterior part of the.Scro-um derives  Nerves f«nn
the Lumbar, and the posterior from the Pudenal Nerves.
  The Scrotum  assists  in supporting and protecting the
Testes.
   Under the Scrotum are two  Membranes or coats, pro-
 per to fach  of the Testes,  the one  termed  Vaginalis, the
 other Albuginea.
   The Tunica Vaginalis, named from its forming a sheath,
 is of the same nature  with the Peritoneum, being originally
 a Process of that Membrane, which in the Foetus descends
 with the Testicle from the Abdomen.
   It forms a shut Sac,  which lias no communication mRh
 any other part.
   It  incloses the Testicle, as the Pericardium does the
 Heart,  and  lies loose  every  where,  excepting behind,
 where it is continuous with the Albuginea.
   It is considerably  larger than the Testis  which it in-
 closes, reaching  as far above and below it as to allow it
 a certain degree of motion.
   It is connected by it* external Surface to  the Cremas-
 ter Muscle,  and partly, by meaiis  of that, to the inner
 Surface  of the Scrotum.
   It assists the Cremaster  in supporting the Testis, and,
 by being  constantly moistened within by a fluid exhaled
 from its Surface, and from that ofthe Tunica Albuginea,
 it allows the Testicle to move easily.
   The Tunica Albuginea, so called   from its white colour,
 is, like  the former Coat, a continuation of the Peritone-
 um, and invests the Body of the Tesiicle closely. 
                         lo2

  It is a thick,  strong,  dense,  and inelastic Membrane,
of a glistemng appearance.
  It is remarkably smooth orf'the outside, but internally
it is rough and  unequal, adhering every where firmly to
the Body of the  Testis.
  It covers both  the Testis and Epididymis, connects
them to each other, gives strength to them,  and conduct!
their Vessels in the manner  the Mesentery does thosei, ,
the Intestines.                                      fM
  The Body of  the  Testis is of a yellowish colour, anil
has a Pulpy appearance,—is of  an oval form, a little flat-
tened at its outer and inner Surface;—and frequently one
Testicle is a little larger than the other.
  The  Testes  are placed  obliquely,  with  one  endup-
wards, and the other end backwards and downwards. >
  At the outer and back-part ofthe  Testis,  thereisan
Appendix, named Epididymis, from its situation upoj#:
Testis or Didymis,  which  is enclosed in  the same cm-
ing with the Testis itself.
  The/Epididymis  begins at  tbe upper part of  thjt Tes-
ticle immediately above  the  entry of the Blood-vessels;
and this part ®f it being large  and of a round form, is
termed Globus Major, or Head of the Epididymus.
  In its descent, it becomes somewhat smaller and flatter,
and is attached behind to the Body of the Testicle, where
rhe Blood-vessels go in ;  but forwards it is loose,  the Tu-
nica Albuginea dipping  in thiupjace, and forming a Ca^
or Pouch.                                         —,
  The under part  of it becomes more firmly attachjrw
the Body of the Testicle, and forms the  Canda, or GUka
Minort it  is  then turned backwards upon itself, after
which it sends out the Excretory Duct of the Testicle,
  The body of  the  Testis has numerous  Arteries, Veins,
Absorbents,  and Nerves; but is principally composed ot
a collection  of minute,  tender,  elastic  Filaments^ intri-
cately  convoluted, termed  Tubuli Seminiferi, or Vasa St-
minalia.
   The Tubuli Seminiferi are disposed in  Fasciculi or Bun-
dles, between Partitions,  which are formed of Blood-ves-
sels and Cellular Substance.
  'These Septulae begin at the root or Nucleus,  situated
at the back-part of the  Testicle,  sometimes termed Cw 
153
pus Higbmorianum, and extend in a radiated manner to
Tunica Albuginea.
  The Testis is fixed behind by  its Vessels, which are
collected into a Cord termed Spermatic,  but  is loose and
free before, to prevent it from being pinched.
  The Spermatic cord, properly so  called, extends  from
the Ring of the External Oblique Muscle to the Body of
the Testis, and is composed of the Trunks of the differ-
ent Vessels belonging to the Testicle, and of a quantity
of Cellular Substance.—The Cord is covered by the Cre-
master Muscle; and within this, by the same Process of
the  Peritoneum which forms the Tunic  Vaginalis Testis.
This part of the Process, however,  is  so incorporated
with the common Cellular Substance of the Cord, as to
appear to form part of it.
  The under part of  the Vagina of the Cord is separa-
ted by a Partition  formed by the upper end of the Va-
ginal Coat of the  Testicle, and by condensed Cellular
Substance,  so  that no  liquor can past easily from the
 Cord to the Testicle, and vice versa.
   The Arteries ofthe Testes, termed  Arterix-Spermati-
 cx, and Arteri* Preparantes, arise one on each side, from
 the fore-part ofthe Aorta, a little  below the Renal Ar-
 teries.
   The Spermatic Artery crosses over the Psoas Muscle
and Ureter, and descends, behind the Peritoneum, to
the  under part ofthe Abdomen.
   At the lower part of  the Abdomen,  it perforates the
Ring ofthe External Oblique Muscle, and passes  in the
Spermatic Cord to the Testicle.
   In its descent, it gives branches to the adjacent parts,
and is so interlaced with  those of  the corresponding  .
Vein, as to have been supposed by the  Ancients to have
large lateral communications with them.
   After passing the Ring, it divides into Branches whicli
go to the Testis at its posterior edge.   They are partly
dispersed upon the Epydidymis, but the larger Branches
run  in a serpentine direction  into  the Substance of  the
Testis, where they  are  minutely distributed  upon  the
Surface of the Seminal Tubes.
   Besides  the Spermatic  Artery, there is a smaller one
 from the Hypograstic, which accompanies the Vas De-
 ferer«  and i« disnersed alontr with the other ArteiY. 
154
   The* Veins are much larger than the corresponding Ar-
 teries, icnd have severafValves in ihem, e.-peckdly with-
 out the'Abdomen.
   They form a Plexus, which accompanies the Artery
 on each side, and is  sometimes  called Corpus Pampyni-
forme, being compared ro. the shoots of tieVine.oi
 Corpus Pyrimidale, from giving a  Pyramidal form to thV
 Cord.  '                                           f
   The Plexus ascends in the  Abdomen, and upon th«-
 Surface of the psoas Muscle; and about the  part where
 it recedes  from the  Anery,  it  forms a single 'Trunk,
 which, in the right side terminates in the  Vena C ivj,
 nearly opposite to the Artery, ami in the left, side, gats
 into the Renal Vein.
   There is also a small inferior Spermatic Vein, wliicli
 accompanies its  Artery,  and  eiuta in the HipogfastK
 Vein.           *■
   The Tubuli Seminiferi  in the  Body of the Te
 consist of numberless  extremely  minute  Ducts, which.
 are of a Cylindrical form, have.no division into Branch!
 es, and when drawn out, are found to be several feet in
 length.
   They  7^0 first collected into Bundles, between the
 Sep'ulx of liie Testicle, aiid these agairtinto others still
 smaller, each of the smaller being formed of a simple
 Tube, coiled up into  a Conical form  with its Base for-
 wards, and its apex towards the  posterior edge  of the  *
 Testicle.
   From the convoluted Seminal Tubes,  an  equal num-
 ber of straight Vessels are  sent  out at the back-partljfa
 the Testicle, under the name of Vasa Recta.
   At the  upper and back-part of the Testicle, the Vasa
 Recta communicate,  and  form an  irregular Plexus  or
 Net-work, called Rete Vasculosum Testis.
   Tbe Lete 7e*fi*.sends out  from twelve  to eighteen
 Tubes termed Vassa Efferentia, which carry the  Semen
 from the Testicle to the Epididymis.
   The Vassa  Efferentia  soon become convoluted, and
 form Conical Bundles, termed Coni Vasculosi.
   The Coni Vasculosi  are  .firmly connected by  Cellt'ar
 Substance,  and are  observed by  Dr. Mo mho, in  hi*
 Treatise De Testibus,  to compose somewhat more than
 a third part of the Epididymis. 
155
  The  Vascular  Cones gradually unite  into a single
Tube, which constitutes the rest ofthe Epididymis, and
though only about the size of a Hog's Bristle, transmits
the w »-,le ofthe Semen.
  The single Tube becomes  larger in its course and less
convoluted, and_at last, expanding its convolutions, it
comes out  greatly increased  in  size,  and almost in a
straight direction, under the  name of Van Defcrenes.
   Besides the DcKts already described, a has Aberrant
is sometimes observed, which is one of the Vascular
Cones,  wandering off,  and terminating in the Epidid) -
mis lower than usual.
   At other times, the same kind of Vessel forms a Pro-
cessus Cxcus, or blind Duct,  with a dilated, extremity
which does not communicate with any other part.
VESICULtE  seminai.es and pros-

               tate GLAND.


  The vesicul* Seminales are two small  Pyriform  Re-
ceptacles, situated between the under and lateral parts
of the Bladder and the Intestinum Rectum,—about three
fingers-breadth in length,  and  the third part of that in
breadth, and a little flattened.
  They are at a considerable distance from each other
behind, but anteriorly they converge, and become  con-
tiguous, forming a sharp angle.
  Each of them is composed of a convoluted Tube, with
irregular Processes, and surrounded by a quantity of tough
Cellular Substance, and by many Vessels and Nerves.
  Internally, they have a Villous appearance and are form-
ed of irregular Cells which correspond with the irregu-
larities on their External Surface,  and communicate
freely with each other.—Their shape, size,  and general
appearance, however, vary in different subjects, and not
unfrequently in the sortie person. 
  Between the Vesiculx Seminales, the ends of the Vasa,
Deferentia, now become larger  and Cellular,  pass for-
wards till they arrive  at  the  Prostate Gland,  where
each Vas Deferens joins the Vesicula of that sidf*., and
communicate  so  freely with  it, that injected  Fluids
readily pass from the one to the other.
  From each  Vesicula Seminalis and Vas Deferens of
the same side, a small Canal, about a finger breadth in
length,  passes out which  is firmly  connected to its fe|..
low, without communicating- with it,  and becomes gra-
dually smaller, piercing, obliquely,  the Prostate  Gland,
and terminating in the under part of the Neck of the
Bladder.
  The Orifices of these Canals are separated from each
other by a. Caruncula,  or round Projection ofthe Mem-
brane of the  Urethra, termed vcru Montanumir-ox,
from being broad behind and rostriform before,  it is con-
pared to the head and beak of  the Wood cock,  andfjjfe
ed Caput Gallinaginis.                            %
  The Vesiculae Seminales are commonly consideresfas
Reservoirs  of the Semen, receiving it from the Vasa
Deferentia, and  afterwards,—by a power inherent in
themselves, assisted by the action of  the  neighbouring
Muscles, particularly of the J.evatores Ani,—propelling
U to the Urethra.
  The Semen is prevented from passing into the Blad-
der, the opening  from it being  shut while that Flutyi
expelled.                                       >*
  Various experiments have been made on the Vesitt
Seminales by the late Mr.  Hunter, from which he m  I
of opinion, that they are not Reservoirs of Semen, bit
Glands, secreting a particular Mucus;—that, with othtt
parts, they are subservient to the purposes of Genera.
tion ;—and that the Bulb  of  the Urethra is the recep-
tacle of the Semen in which it is  accumulated  previous ,
to its ejection.
  The Prostate Gland, named from  its  situation  before
the Vesiculaca  Seminaks,  lies  immediately behind  the
under end of the Symphysis of the  Pubis, and rests up-
on the Intestinum Rectum.
  It surrounds and closely  embraces  the  Neck  of  the
Bladder, or beginning of  the Urethra; but the  greater 
                         Ul

 part of it is  placed posteriorly and laterally, having 3
. Lobe projecting on each side.
    It. is about the si/.e of a walnut, and of the figure of a
 Spanish chesnut,—or it resembles a heart as commonly
 painted on Playing-cards,  with the Base towards the
,, Bladder, and the Point towards the Penis.
    It has a Spongy Substance,  but is one of the firmest
 Glands of the  Body,  and generally  sends out ten or
, n.-ehe Ducts, which  open obliquely at the beginning of
j, the Urethra, at the sides of the Caput  Gallinaginis and
 near the termination ofthe Seminal D,ucts.
    From the Diets of  the prostate (dand, a thin white
 X-iqitor is discharged,—from  the  same causes,  and at
 the same time with the Semen,—into the  Urethra,   and
 is supposed to be useful in  the process of Generation ;
 —or, according t" some Authors,  this  Fluid facilitates
 the prsfcage of the Semen through the Urethra. .
    T'ne Blood-vessels,  Absorbents,  and Nerves of the
 Vesicula: Seminales, and Prostate Gland, a re in common
  »tth those ci the ports which  suriuund liiem.

                        PENIS.

    The Penis, which  has  obtained a  variety of  other.
 names, and  as  Mnnbrum Virile, Mentula, &c. consists
 of three .spongy Substances, two of which form the up-
 per part and sides, or Body ofthe Penis, and are term-
 ed Corpora Cavernosa  Penis,  the  third surrounds the
 Urethra, and has the name of Corpus  Spongiosum Ure-
 thra.
    The Penis is covered with a continuation ofthe com-
 mon  Integuments, which are  thinner  than elsewheie,
 aid. instead of Fat, there is as in the Scrotum, a Reti-
 cular Substance only under the Skin.
    At the anterior extremiy ofthe Penis, the Integu-
 ments^oim a loose fold, termed Prepuce, which  is con-
 nected to the anterior and under part,  or Glans of the
 P«nis, by a triangular fold, called Frxnutn  Preputii.
    The Corpora Cawrsnna Penis resemble two equaj but
 irregular Cylinders,  closely applied to the sides of each
 other, and im u covered by a  strong, elastic, Ligamen-
 tous Sheath, the Fibres of  which  run  in a transverse,
 and partly in in oblique direction. «
      voi.  t;.              ,r. 
                        158

  They arise one on each side, by two blind Conical ex-
tremities, called their Crura, from the inner part of the
Crura  of  the  Ossa Ischia and  Ossa Pubis, to both of
which they are very firmly connected by Ligamentous
Substances.
  At the under part of the Symphysis of the Pubis,
they are united to each other,  and continue so till thej
reach the  Glands, where they terminate in a rounded
extremity,
  At the upper part of the root of the Penis,  the Lig».
mentous Sheath of the Corpora Cavernosa sends up a
process of  a  triangular form, to  be connected to the
Symphysis of the Ossa Pubis,  under the name of Liga-
mentum Suspensorium,  by  which the Body of  the Penii
is supported, and  prevented  from passing too much
upon the Scrotum.
  The Corpora Cavernosa leave  a Groove above, forth
principal Vein of the Penis, and a Channel below faff*
Cavernous Substance of the Urethra.
  The internal substance of the Corpora Cavernosa con-
sists of loose reticular  Plates,  somewhat similar to the
Cancelli in the ends of long Bones,  and, like them, rea-
dily communicating with each  other.
  Upon the Cells of  the Corpora Cavernosa, the Arte-
ries are plentifully dispersed, and open freely into them,
the Blood of the Arteries tinging the Cells in the relax-
ed state ofthe Penis, and filling them completely wh«
it is distended.
  The Corpora Cavernosa are united to each otherfji
Septum or Partition, formed  by  a continuation of the
elastic Ligament which covers these Bodies.
  The Septum penis is  composed of Cords, extending,
nearly in a  parallel direction, from the Dorsum, or up-
per part of  the Penis, to the  Corpus Spongiosum Ure-
thrae.
  Between  the different Cords, Fissures are left, through
which the Blood, or an injected Fluid,  passes  without
obstruction  from one of the Corpora  Cavernosa to the
other.
  The Corpus Spongiosum Urefhr* is situated under and
betweenfthe Corpora Cavernosa Penis, but projects con-
siderably beyond them.                  l   J
  It begins  a little behind the part where the  Corpora 
159
Cavernosa  are united, adheres to  them by condensed
Cellular Substance, and terminates at the anterior ex-
tremity of the  Penis.
  It has an external covering similar to that ofthe Cor-
pora Cavernosa Penis,  but more delicate and more of a
Membranous appearance.
  The posterior part of the Corpus  Spongiosum is dila-
ted into a longitudinal prominence, of a conical form, situ-
ated within the Skin of the Perineum, and termed Bulb
of the Urethra.   It  extends from the root ofthe Penis
to near the Anus, projects most towards the undenend
back part, and is divided anteriorly by a Septum.
   The Corpus Spongiosum is continued along the under
part of the Corpus  Cavernosa, and  at the end of  these
expands into  the Substance called  Glans penis,  which
covers and incloses the ends  of the Corpora Cavernosa.
   The Glans, or Nut, named from its resemblance to an
Acorn, is separated from the Corpora  Cavernosa by a
continuation of the  Ligamentous Sheath which covers
them, and  is encircled at  its posterior part by a^romi-
nent margin,  called corona Glandis,  behind which is a
CerVix or Neck.
   The Surface of the Glans is covered  with a. plexus,
chiefly of  Venous Vessels, and  with Nervous papill*,
which give it  its sensibility j and these are inclosed in a
fine Membrane continued from the  inside of the Pre-
puce.
   About the Cervix and  Corona of the Glans, are many
Follicles, termed  Glandula Odor if era, which discharge a
Sebaceous Matter,   to preserve  the sensibility  of  the
 Glans, and allow the Prepuce to  move backwards and
 forwards upon it with  facility.
   The Internal Structure ofthe Bulb of the Urethra and
 Glans of the Penis, is of the same  nature with that of
 the Corpora Cavernosa;  and the Internal Structure of
 the rest of the Corpus Spongiosum  differs from that of
the Corpora  Cavernosa only in this,  that the Cells  are
smaller and of a  more delicate texture.—Some Anato-
mists consider the greater part ofthe Corpus Spongio-
sum as merely a Plexus of convoluted Veins.
   The Urethra, named from the Urine passing"through
 it, is a long Canal,   the  Diameter of which is nearly
 equal to that of a  writing-pen.   It begins at the under 
160
and fore-part of the Bladder, runs through the Corpus
Spongiosum, and terminates in  the point of the Penis
by a longitudinal Orifice.
  At its Origin, it descends  a little, and then passes
forwards, under the Symphysis of the Ossa Pubis, «u
which it is closely connected by Cellular Substance: Ft
then ascends at the  under and fore-part of the Ossi
Pubis, varying in the remainder of its course accordM,
to the different degrees of relaxation or distension of ttf
Cells of the Penis.
   There are commonly three Dilatations in the Urethra;
one of which is at the Prostate  Gland, the second in the
Bulb of the Urethra, and the third about the beginning
of the Glans.
   In general, it has also the same number of sligblcon-
tractions,- the first  at  its origin from the Bladder,]^'J
second between the point of  the Prostate Gland ami
Bulb of the Urethra, and the  third at the point offe
 Glans.
   Between tne point of the  Prostate Gland  and part
 where the  Urethra penetrates  the Corpus Spongiosum,
 —including nearly the space of a fingers-breadth,—the ■:■»
 Urinary passage is entirely  Membranous,  and covered   I
 only with the common Cellular Substance.
   At the upper side of the Bulb, the Urethra enters the
 Corpus Spongiosum, in which it is inclosed to its ter-
 mination in the point of the Penis.                 .
   The inside of the Urethra is lined by a very Vai$k
 and sensible Membrane,  which  is observed  to po^sessi
 certain degree of contractility, and is therefore presum-
 ed by several Anatomists to be endowed with Musculuar
 Fibres.                                              j
    Between the Corpus Spongiosum  and  the Membrane 1
 which lines the Urethra, especially towards the Septum
 of  the Penis,  numerous Lacun* of different  sizes are
 situated, one or two of which in  particular,  next the
 Glands, are often considerably larger than the rest.
    They run in a longitudinal direction from behind for-
 ward,  and perforate the Urethra by Orifices large
 enough to admit a Bristle.—The  discharge a bland Mu-
 cus for the defence of the Urethra.
    Besides  the Lacunae, two small bodies, each about the 
161
size of a Garden-pea, are frequently met with, and are
termed, from their discoverer, Cowper's Glands.
  They are situated at the sides of the Membranous
pan ofthe Urethra,—between its Bulb and the point of
the Prostate Gland,—and  covered by  the Accelerator
Muscles.
  When present they are observed to discharge from
their Ducts into the Urethra, a Fluid which is supposed
to serve the srjme purpose  with that of the Lacuna.
  The Arteries of the  Penis are chiefly from the  Pudi-
cx Communes, which are Branches of the Internal lil-
acs, and partly from the Femoral Arteries.
  Each of the  Pudic  Arteries having passed out of the
Pelvis, through the great Notch of the Os Ilium,'runs
between the  Sacro Sciatic Ligaments to  the inner side
of the  Tuber Ischii.  from which it  passes  along the
Cms of that Bone, and of the Os Pubis to the root of
the Penis.
   In ;ts course,  it furnishes Branches  to the adjacent
parts, and afterwards  gives off three principal Branches
which belong to the Tenis:—One of these  goes to the
hulb ofthe  Ore: hra, to be dispersed in the Corj-us Spon-
giosum;—the other two, which are larger than the for-
mer, go to the Body ofthe Penis, one of them penetra-
ting its Cms, and running in the  centre of the  Corpus
Cavernosum ; the other passing between the  Symphysis
Puhis  and joining of the Crura Penis, and extending
along the Dorsum as far as the Corona  Glandis.
  The Branches of the Femoral  Artery  to  the Penis
ct ninunicate with these of the former, and ate chiefly
dispersed upon  the Integuments.
   '1 he Arteries of the penis  are divided into  minute
Ramifications, which communicate with each other, and
with their fellows on the opposite  side, and terminate
partly in the  corresponding  Veins, and  partly in the
C'i lis of the penis.
  The Vtins  arise, seme from the extremities of the
AniTitr;,  and o-.hers  b\  large open Mouths from the
L'( lis <if the penis.
  '1 he greu'er number <f the Veins unite into a Trunk,
C-tllcd vena  Magna J'c\is,  which iuus  in tbe superior
Groove lonr.ui In tlie union of the Ccrpoia Cavernosa
                        i. 2 
                        162  '

.and is furnished  with Valves,  and  with thiok strong
coats.
  The Vena Magna, at the under end of the Symphysis
Pubis, separates into the Right and Left Plexus, wh\k  ,
pass to the corresponding Iliac  Veins.                 .-
  To an obstruction ofthe course of Blood through the '
Veins, by the pressure ofthe Muscles at the root of the
penis, together with  an  increased influx through the
Arteries, is  owing  that  accumulation of, Blood in the   /
Corpora Cavernosa, which occasions a distension of tlie*" '
penis.
  The relaxation of the penis  happens from the causes
which produced the  distension, being removed;—The
Elastic Ligamentous  Membrane which over:- the pe-
nis again forcing the Blood from the Cells in the Vein1".
  Upon  the Surface  of the penis,  there are small sh-
periicial  Veins, which communicate with thoae differ
seated, and commonly  terminate by one or more iHH*-
ches in the Veins at the top ofthe Thighs.
  These Branches assist in carrying ojn. the circulation,
and return part of the Blood  during the dimension of
the penis.
  Of  t.Aj Lymphatics  of the penis, from those of the
prepuce  and Skin,  in  general, go to  the right and left
Inguinal Glands, while the Lymphatics  from the Glauv
and Body ofthe penis accompany the  Arteries into tiis
under part of the pelvis.
  Tlie Nerves of the penis are large in proportion to t'n
size of that Organ.  They come from the Hypo^rastil
plexus, and principally from  the last Sacral Nerves,
are distributed chiefly upon  the  Ligamentous Sheat
which incloses the Corpora Cavernosa.
  They  are  situated upon the Dorsum of the penSf?
more laterally  than the Arteries which lit between thera
and the  principal vein.
   For the Muscles of the penis, see part II.
  The penis ejects the semen into the Vagina, and serves
for the conveyance of the  Urine from the Bladder- 
OJT THE
ORGANS OF URINE AND GENERATION

               IN THE  FEMALE.
   The Kidreys,  Renal Glands,  and Ureters,  have the
 same situation and structure as in the Male.
   The Bladder  has also  the same situation behind the
 Ossa Pubis, but rises higher when it  is iri the distended
 ,,.ite.
   It  is proportionally  larger  than the Bladder of the
 Male, a id is broader from one side  to the other, cor-
 responding to that part of the  Cavity of  the pelvis to
 which it belongs.
   The Urethra is much  shorter,—being  scarcely two
 inches in rtngth,—and straighter than in the Male, hav-
 ing only a slight bend downwards  between the extremi-
 ties.
   It  :s produced from  the most depending part of the
 Bladder, has no prostate Gland, but is furnished, as in
 tf»« Male,  with Lacun*,  which open  into  i^  and dis-
 charge a Mucus to defend it from  the Urine.
   The Parts of Generation in  the Female (which are
 f.ere  supposed to be in the unimpregnated state)  are
 divided into Internal and External.  The  former consist
 ofthe Uterus  and its Appendages, the latter are those
 which are seen without any dissection.

                    Internal Parts.
   The  Uterus Matrix,  or Womb,  is a hollow Viscus,
 situated in the Pelvis, in  the  Hypogastric Region, be-
 tween the Bladder and Rectum, with  which it is  con-
< ncc ted.
   It  is of a triangular figure, and a little flattened before
 nn.l behind, but more so anteriorly ; is large above, small
 below, and has two angles at its upper and laterii parts,
 called Ccrners of the L'iei.12. 
1G4
  It is distinguished into Furulus, or  tipper part, which
includes the space above the insertion of the Fallopian
Tubes, the Body or middle, and cervix or under part, the
two last being nearly of equal length.
  The extent and figure of the Uterus varies consider*.
My in different subjects.—In Women who have  never
been pregnant, it is commonly  about two inches and a
half in length, from one inch and a half to two inched
breadth atthe Fundus, and about half as broad at the Cfc
vix.—It is near an inch in thickness, and is larger in Wo-
men who have borne children, than in the virgin state.
  The Cavity, like the External part ofthe Uterus, is of
a triangular form, but is small  in proportion to the site
ofthe Organ,—being scarcely capable of containing the
Kernel of an Almond,  and has its sides closely applied
to each other.
  It  is covered  externally through its whole length1
with a smooth polished coat, continued from the Peri-
toneum, which, atthe underpart of the Cervix,  is re-
flected forwards upon the Bladder, backwards over the
Rectum, and laterally towards the sides of the Pelvis.
  Its  substance is of a compact, Cellular,  and Fleshy
nature, and plentifully supplied with Blood-vessels:
The Fleshy Fibres, however, are seen distincdy only it*
the Gravid Uterus.
  It is remarkably vascular in its Body, less so  inju
Cervix, and is nearly ofthe same thickness through
excepting at its corners, where the Uterine or Fallop
Tubes terminate.
  It is lined with a fine  and  very vascular Membranes
of a.spmewhat porous  and villous appearance, in which
the Arteries terminate which discharge the Menstrual
Fluid.
  The Cavity of the Cervix has  two small  Longitudinal'-i
Lines projecting in  it,  one in  the anterior, the other in
the posterior part, on each side of which are numerous
Rug*.
   The Rug* run in  an obliquely  transverse rffrection,
and are formed not only of the inner Membrane,  but
also by  the Fibres which compose  the Body of  the
Uterus r*
  Between the  Ruga;  are  many small Follicles,  which
discharge a Motus for lubricatinsr the narrs near  which
in id

lopTkirw 
165
they are placed:—Some of them,  being df a roundish
form were mistaken by Naboth for the Female Ovula.
  The under part of the Cervix projects into  the Vagi-
na, somewhat in form of the .Glans Penis, and is perfo-
rated, by a  transverse slit, termed Os Tine*, from  its
supposed resemblance to the Mouth of the Tench Fish.
  The Os Tine*, in an Uterus which has never been im-
pregnated, is about the size of the  orifice of the Ureth-
ra in the Male, but nearly twice  as large in the Uterus-
of a Wonaan who has borne children.
   li is smooth on its external surface, is placed oblique^
ly in a direction towards the back-part of the Vagina,
and is surrounded by several Mucous Follicles.

               Appendages of the Uterus.

  The Appendages of the Uterus,  arc the  Broad and
Round Ligaments, the Ovaria,  the  Fallopian Tubes, and
tut* Vagina.
   The Li<ramenta Lata, termed sometimes Al* Vesper-
tilionis, from their resemblance to the Wings  of a  Bat,
are two Membranous productions;  or Doublings  ofthe
Peritoneum, sent from the edges of the Uterus and pos-
terior extremity of  the Vagina,  to be fixed to the sides
ofthe Pelvis.
   Along with the Uterus, they separate the Pelvis into
anterior and posterior Ca.ities. and are themselves di-
vided into large and small, or anterior and posterior Altc
or Pinions.
   They contain and  support the  Ovaria  and Uterine
Tubes, with  part of the Spermatic and Uterine Vessels
 and Nerves. 'They likewise inclose a portion of the Liga-
 menta Rotunda, 8cc. connect  the Uterus  to the sides of
 the Pelvis, and assist in retaining it in its place.   In the
 lime of Gestation they become effaced,  by  furnishing
 rhe Uterus with part of i*s exlermil covering.
   The Ligamenta Rotunda  are  two long  and  slender
cords, composed of Vessels  and  Ligamentous Fibres,
arising from the corners of the Uterus, immediately be-
fore and  below the Fallopian Tubes, from which they
descend obliquely in the Ligamenta Lata,  diminishing
a little in their course towards the  Groins.
   They pass through tfie Rings of the Abdominal Mus- 
                       166

ties, in the same manner as  the Spermatic Cords do in
the Male, and afterwards inserted by separate Branches
into the upper and lateral parts of the Pudendum.
  They assist the Ligamenta Lata in preserving the
equilibrium ofthe Uterus.
  The Ovaria,  anciently called  Testes,  Muliebres, are
situated at the sides ofthe Fundus of the Uterus, about
an inch disiant  from it, and are contained in the poste.
rior Pinicms of  the Ligamenta Lata, which form a coat
to them similar to the 'Tunica Albuginea Testis.
  The Ovaria are plain atjpve, and prominent and semi.
oval below, flattened at their anterior and posterior Sur-
faces, and the size of each, when in a state of the great*
est maturity, nearly equal to half of the Male Testicle.
  They are large,;uniform, and smooth, in the vigour*?
life, but become small, unequal,  and shrivelled, in Old
Women, or in those who have borne many children. .»
  They are attached to  the  Uterus by  the  LigamenqT
Lata, and by two small cords, termed  Ligamenta Rotm
da Ovarii, which  were mistaken  by the Ancients foe
Vasa  Deferentia,  carrying  a secreted Liquor to the
Uterus. -
  They are composed  internally of a loose whitish Cel-
lular Substance, intermixed  with  Vessels and Nerves,
and contain a number  of small Vesicles, called Ova, fil«
led with a limpid Fluid, which partakes ofthe qualities
of the white of an egg.
  These Vesicles differ much in size in the same Ovari.
um;—the largest of them are seldom equal to the size
of a small Garden-pea.
  The number  of Ova is differently estimated by differ-
ent Anatomists,—from ten to twenty and upwards hav-
ing been found in one Ovarium.
  According to experiments made by Mr Hunter, it
is ascertained,—that the number  of originally existing
Ota in each  Ovarium, whether that number be greater
or smaller, may be diminished, but cannot be increased.
  The Ovaria serve for the nourishment of the Ova,
which contain the rudiments of the Foetus.
  The Uterine,  or Fallopian  Tubes, compared in shape,
by Fallopius, to that of a Trumpet,  are two Conical
Vermiform Canals, attached to the corners  of  the Ute* 
                        167
                           /
rns,  and terminating in it, each  by a  mm// Opening
which scarcely admits the entrance of a Bristle.
  They become gradually larger in  their passage  to-
wards the sides of the  Pelvis :  Near their outer  extre-
mity, they are convoluted and considerably dilated, but
are afterwards  suddenly contracted, and terminate by
open Mouths  sufficiently large  to admit the  point of a
Goose-quill.
  Their outer ends are free  and fluctuating in the Pel-
vis, and expanding into many irregular jagged or poin-
ted extremities, called Fimbria, which are considerably
longer at one side of the Tube than the other.
  They are commonly  upwards of  a hand-breadth in
length, and contained in a doubling 6f the Ligamenta
Lata—In their natural situation, they lie  near the Ova-
ria;  but when drawn out and extended, are-a finger's-
breadlh disiant from them.
  The structure of the  Tubes  is nearly the same with
that of the Uterus, and, like it, they are capable of dila-
tation and contraction :  Their inner side,  however, has
a different  appearance, being furnished with many small
longitudinal Plica:, which are most  conspicuous towards
the outer extremities.
   The Tubes are  supposed  to  convey the prolific part
of the Male  Semen from the Uterus to the Ovaria, in
order to fu-cundate the Ova? and by grasping that part
o( the Ovarium where  the  ripest Ovum  is situated, to
carry the OViwn, according to some Authors, or its con-
tents only according to others,  to  fie mixed  with the
Male Semen, and to be lodged in the Cavity  of the
Uterus.
  The Vagina is a Membranous  Canal, which extends
from the Neck  of the Uterus to  the opening  of the
Pudendum.
   It is situated behind the Bladder and Urethra, and be-
fore the vnder part of the Intestinum Rectum, to each
of which it is closely connected by Cellular Substance.
 • It begins a little above the Internal Orifice  of the
Uterus, but reaches higher at tbe posterior than anterior
part ; from which circumstance, together with a slight
Orvature, it has backwards,  the Canal is found to be
longer in its posterior than anterior Surface.
  From tl.c  Os  Tihc<c, it pastes downwards and for- 
168
ward"?,  and  terminates  between  the Labia  Pudendi
the Axis of the  Vagina  forming a considerable Angle
with that ofthe Uterus.
  The dimensions of the Vagina correspond with the
size of the Penis in the  Male;  but vary according to
the temperament  of the Body, and become larger in
Women  who have borne children.
  The Body ofthe Vagina is composed of thick, stroa|
Membranous parts,  and  furnished internally withs*
merptts irregular  Ruga  or Wrinkles, and Nervous A-
pill*, the former of  which considerably diminish the
capacity of the Canal, and the latter add to its sensibi-
lity.
  The Rug* run in a transverse direction, and are so dis-
posed as to divide the Vagina into anterior and poste-
rior Columns, which join together laterally, and pro'ducal
a Raphe or Suture at the right and left sides.       ip
  Tliey are deepest,  largest,, and most  crowded upa
true anterior and towards the outer part of the Vagjjra;^
are most conspicuous in Virgins, less  so  in martiefj
women,  and become more  and more effaced in those
who have borne children.  The  Rugae facilitate the dis-
tension of the Vagina during child-birth.
  The whole extent ofthe Vagina, particularly towards
its outer extremity,  is  furnished  with small Follicles*  '■
the orifices of which can frequently be seen.        -flr
  They  supply the Mucus, with which the Canal issf
ways lubricated, and which is  discharged,  in tinmpf
Coition in such abundance,  as to have  been fortify
considered as an emission of female Semen.
 i The outer end of the Vagina is covered on each side,
by  a Substance composed of Blood-vessels and Cells si-
milar to those ofthe Penis, and described by De Graaf
under the name of Plexus Reteformis,  and by later An-
atomists under that  of Corpus Cavernospm Vagina.
   The Corpora Covemosa  are covered by the Sphincter
Vaginre Muscle, the action of which, joined to the Dila-
tation of these Bodies, serves to  contract the entry of
the Vagina in the time of Coition.
   The use of the Vagina is  to receive the Penis and
Semen,  and to convey from the Uterus the Menstrual
Flux, and Foetus, the Secundines, and the Lochia.
   The Uterus, with its Ligaments, Ovaria, and Uterir.e 
                        169

Tubes, are supplied with Blood from the Spermatic and,
Uterine Arteries.
  The Spermatic Arteries arise from the Aorta, as in the
Male/and run in the Ligamenta Lata,  to be dispersed
upon the Ovaria and Uterine  Tubes, and afterwards up-
on the Uterus itself.
  The Uterine Arteries are derived from the Internal Ri-
ses, and are much-larger than  the  Spermatics.  They
dircct their course, first to the under part of the Uterus,
after which  they  ascend along its edges, and near its
upper part join the Spermatic Arteries.
   From the Uterine chiefly,  and partly from the Sper-
matic  Arteries, many  small Branches are furnished,
which run in a serpentine  manner,  and  communicate
with their fellows in the opposite sides of the Uterus.
  The Vagina is supplied w ith an artery on each side,
—termed Vaginal,—from the Uterine, and with small
Branches from  the  umbilical,  Middle  Hxmorrhoidal,
and Pudenda; Communes.
   The: S/tiermrir/c Veins  have the same termination as in
the  Male, but  are considerably  larger.—The  other
Veins runs into the Internal Iliac.
   The  Lymphatics, like the  Blood-vessels, run  also in
two Sets.  Those  of the one 6et accompany the Sper-
matic  Blood-vessels, and, 'like the  absorbents  of the
Testes in the Male,  go to the Lumbar Glands.  1  hose
ofthe other correspond with the  Hypogastric. Blood-
vessels, and terminate in the  Glands at the lateral parts
of the Pelvis.
  The Nerves are  from the  Sacral and Great Sympa-
thetics.
   The use ofthe Uterus is,—to receive from the  Ovaria
by means of the Fallopian Tubes, the Rudiments of the
Foetus,—to nourish it, and, after bringing it to maturity.
—to expel it through the Os Interinum Uteri and Va-
gina—From the Inner Surface of the Uterus, the Men-
strual Evacuation is also discharged.

                   External  Parts.

  The external parts,  called  Pudendum or  Vulva,  are
formed of two prominent sides, termed Labia Pudendi,
Labia Externa, or  Ala Majorat.  These  are contiguous* 
170
when the Limbs are not much  separated,  thereby pre-
venting the access  of  the  Air to '.he Internal  Parts,
which they at the same tim£ protect and conceal.
  The upper part of the Pudendum,  named Pubei or
Mons Veneris, is  situated on the fore-side  of the Ousa
Pubis', and is covered vith  Hair similar to that  inthe
Male, and beginning tr. grow about the same period of
life.
  The Pubes is composed of the common Integumerift,
under which a considerable quantity of Fat  is siuiaied,(
rendering it thick, soft, and prominent.
  The Labia  Pudendi extend  from the Pubes to within
about an inch of v-he Anus,  the space between the Pn-
dendum and Anus obiainrng the name <if perineum, from
a moisture supposed to flow about this part ofthe Skin.
—It is sometimes  also  called  anterior perineum,  to dia-
tingnish it from  that part which extends from the Amis
to the Coccyx,  termed by  some  Anatomists posterh
perineum.
  'The opening between the two Labia has the name of
Fossa M.igna;—it increases a little in si/.e  and depth ai
it descends, and forms  a small boat-like Cavity at  its
under extremity, termed Fossa  Navicularis.
  The Labia are thickest above, become thinner below,
and terminat'e in a transverse fqld of  the rskin, named
Franum Furcula,  or Fourchette, which is frequently la-
cerated in the first child-birth.                     1
  The Labia are composed  of  the  Skin  elc-vatedjfi
large quantity of Cellular Substance and some Fat,'wd
lined by a very Vascular Membrane, which  is thin, Wil-
der, and red like the inside of  the lips, and is furnished
with  numerous Sebaceous Follicles,  secreting a  Liquor
whereby the parts are preserved smooth and moist.
  Between the upper ends of  the Labia,  is the Sub-
stance named  Clitoris, and by  some  Mentula Muliebrit,
—not exceeding an  inch in length, and little more than  ^
the third part  of that in thickness, and tied down to the  (
fore-part of the Symphysis Pubis.  ,
  It is extremely Vascular and Nervous, and is compc- <
sed, like the Penis in the Male, of two crura and corps*
ra cavernosa, contained in a Ligamentous  Sheath, with
a Septum between them,,
 •v The Crura are upward* of twice the length of the Baj 
171
' ef the Clitoris, avd, together  with  Muscles belonging
 to them, arise, as the O.jra ofthe Penis do in the Male,
 from the Crura of the Ossa ischia and Pubis.
    The Clitoris is also provided  with  a Ligamentum Sus-
 pensoriitm, by which it is  connected  to the Ossa Pubis,
 and  w'kh v. Glans, which,  like  that ofthe  Penis, is ex-
 tremely sensible, but has no perforation  in it for the
 passage of the Urine.
    It is covered by a coniir.uation ofthe Skin ofthe La-
 bia,  which at its inferi'-r extremity,  forms a Semilunar
 Fold, termed preputinum c.itoridis.
    The  Prepuce is furnished  with  Glandula Odorifer*
 upon its inner Surface, and with a small Fraiium which
 fixes it to the  Glans.
    In the time of Coition, the Glans  Clitoridis is suppo-
 sed to produce nearly the same sensation in the Female
 as the Glans Penis does in the Male.
    At the under and outer part  of the  Clitoris* are two
 Bodies called Ny.npha, from  their being  supposed to
 preside over and direct the course of the water proceed-
 ing  from the Bladder.
    The Nympha  arise narrow  from  the Prepuce and
 Glans, and run-obliquely downwards and outwards along
 the inside of the Labia, increasing in breadth, but sud-
 denl) contracting again at their lower extremity.
    They are chiefly formed by a production  ofthe inside
 of the Labia,  have the same   florid  colour with  them,
 and  in their natural state are contiguous, and cover the
 Orifice ofthe Ureihra.
    'They are sometimes  of unequal size, and not unfre-
 quently, particularly in  warm climates, they project be-
 yond the edges of the Labia.
    Their  Internal  Structure consists of 'Celhilar Sub-
 stance, with a. large proportion  of Blood-vessels-  They
 have also  many Nervous  Papillai, which  render them
 very sensible,  and  Sebaceous Follicles, the  contents of
 which prevent them from being injured by  the Urine.
    TJie Nympha* assist  in directing  the course of  the
 Tunc* from the Urethra, and in  preventing the Air from
 entering the Vagina.—They also tend to  enlarge  the
 passage for the child in the time of parturition.
    Between  the  Perineum and N)mpha*,   there is a
 smooth cavit;  or -..\:ibuium, which is most complete  in 
172
Virgins, and leads to two passages, viz.  to the Urethra
above, and to  the Vagina below.
 '  The Orifice  of tbe Urethra is  placed a little below the
Glans of the Clitoris, and between the two Nymphs, and
is  surrounded  by a Spongy Eminence, which projects at
its under part, called  by  some  Author:, Corpus Glandw
iosum, or Glandul*- Prostate Mufierum.
   The Corpus Glandulosum  is  perforated by  Lacurl^.
some of which are of considerable depth, and dischargt
a viscid matter round the Orifice of the Urethra.
   The Orifice  ofthe Vagina teemed likewise Os Externum  '
Uteri, is placed immediately under that ofthe Urethra,
and is naturally straiter than the rest ofthe  Canal, but
in the  virgin   state  is still more contracted by the Sub-
stance called  Hymen,  or  Circulus  Membranosus, which
partly surrounds it.
   The Hymen  approaches to a Circular Figure, but jlL,
Circle is  frequently incomplete next the orifice ofWP"
Urethra, the  broad  part being turned towards the Pe-
rineum.
   When the  Hymen  is ruptured,  it degenerates into
small Conical  Papilla;, termed Caruncula Myrtiformes,
from  their supposed  resemblance to Myrtle berries.
   The  Hymen has  been considered as a Test of Vir.
ginity;—but neither the  presence  nor absence of this
Membrane can be depended  upon as a certain Crite-
rion.
   About the Orifice  of the Vagina are  several MuM
Follicles, similar to those round the opening of the Die-
tbra.
   The Blood-vessels and Nerves of  the  External  Parti
are from the Pudic branches, and are dispersed in nu-
merous Ramifications upon the end of the Vagina, La-
bia Externa, and Clitoris.
   The Absorbents pass partly  to  the Inguinal Glands,
»nd partly to   those placed  at  the sides of  Pelvis, ot
upon the Lumbar Vertebra. 
173
       OF THE  GRAVID UTERUS.

  When the Rudiments  of the Fcctus have been con-
vcved from one of the Ovaria into the Cavity of the Ute-
rus, through the medium of the corresponding Uterine
Tube, whether in the state of a Fluid only, or of a com-
plete Ovum, impregnation is said to have taken place.
  Some davs after Impregnation  has commenced, an
Ovum, consisting of a Vesicle filled with  a limpid Fluid
is found in the Cavity ofthe Uterus-
  The Ovum, when first  visible, is observed to have a
smooth surface, but in a short time thereafter it sends off
flocculent Branches, the greaicr part of which are by de-
grees convened into  a Placenta, at  that  part  of  the
Uterus where the Ovum happens to be first attached.
  The Rudiments of the  tutus, however, are not al-
ways convened to the Uterus after Impregnation, tor
son'.ciinu-s a Fat us is found in the Ovarium ;  at-other
times in one of the Uterine Tubes  ; and  some  rare in-
stances have occurred  where the  Embryo has dropped
frrm one ofthe Ovaria or Tulvs into the Caviiy of ihe
Abdomen, \\ here a placenta has been formed, by which,
it has been nourished
  The Ovum, at an  earlv period of Gestation, consists
of a thin Mtmbranous Capsule, which encloses  the Em-
bryo cr Germ with tbe umbilical cord and wa'ers; and
the Capsule, again,  consists of an  internal Membrane
called Amnios, on the outside of  which is the  True Cho-
 rion, which ia covered with a Filamentcus and  Spongy
 Substance,  termed by Ruysch  Tunica Filarncntosa, and
 by more modi rn Authors, 1-dse or Spongy Chorion.
   The Spungy Chorion  is  described bs Dr. II c nter as
 consisting, in early  Gestation,  of two Layers, one lining
 the Caviiy ofthe Uterus, and firmed by him Mtmbrar.a
 Drcidua, from being supposed to  be  cast  off from the
Uterus; The other covering  that  part  of the Ovum
 which does not adhere to the Uterus, he terms Decidua
Reflexa.
   'Ihe Pecidua is least distinct between the U'erus and
 Place-nia.   Near the edge ot the  Placenta, both it and 
                        1 74

that part of it called Refiexa, are thickest and strongest,
and decrease  in thickness t<>v ards the other end of  the
Uterus and Ovum, in proportion as these become more
expanded.
  The Decidua and Decidua Refiexa unite into  one
Membrane in advanced Gestation. '1 hey have been sup-
posed to be formed originally by an efflorescence throv»<
out upon the  parts on which they are placed, in the m^t
ner it is thrown out upon inflamed surfaces.
  Between the Amnios and Chorion, a Gelatinous Fluid
is contained  in the early Months, at which periods
small Bag, filled with a milky.like Fluid, is observed nti
the  Amnios, near the  Umbilical Cord,  and is termed
Vesicula Umbilicalis or Alba
  The Vesicula Umbilicalis is connected to the Cord by
a Filament consisting of  an Artery  and  Vein,  whicli,
with  the Fluid and  Bag, soon disappear.  The usl|£ ■
this Vesicle which has sometimes been mistaken form
Allantois is not yet understood
  In early  Gestaiion, the Ovum is large  in proportion
to the Embryo; but towards the  latter period of preg-
nancy  the proportion is reversed, as appears from  the
following observations
  No well authenticated account has been _et received,
ef the Embryo being observable lilt near the end ofthe
third week,  wh.-n iris found  to appear like an  oblcnj
Vesicle floating in the limpid  Liquor ofthe Ovum.  ,.
  In the fourth week,  the Ovum is about the size^Fi
Pigeon's tgg and the  Embryo not larger than that of i
common Fly.
  About the end ofthe third month, the Ovurrfis  the she
of a Goose's  Egg, and weighs eight ounces while the
Embryo is  befwem two and three Ounces in weight  and
three inches in  leug-h ; —and  the  Head and Extremities
being now distinctiv observable,  it obtains the  name of
Fatus, which it  retains from this time till the end of
Gestation.
  In tbe sixth  month,  the  Placenta  and Membrane!
weigh seven  or eight ounces, the Foetus, twelve or  thir-
teen, and is eight or nine inches  in length, and perfect
in all us external pans.
  At bir.h, the Sccundines weigh only between one and
two pounds,  the Fotus six or seven,  and is from eigh-
teeu to twenty -two inches in length. 
175
  Still however, from the difficulty of ascertaining when
Pregnancv commences--from  the differences  of  Foe-
tuses of the same age ill different  women,  and in the
same women in different  Pregnancies, and—from the
Foetus  being frequently  retained  in  the Uterus some
time after it is dead, as well as from the small depend-
anceto be  placed  upon many of the  figures given  ot
these Parts,—the above observations are not altogether
to be depended upon.

  Changes produced in tbe Uteri,* System  by Impregnation.

   Irr,mediately  afier  impregnation, a large Orifice is
constantly observed in the Ovarium, leading to a.Cavtty
in tha  part of  it from whence tire Rudiments of  the
Fatus have been derived.
   This Cavity appears first flocculent, and is afterwards
filled up  with a Granulous Substance,  which has the
name of Corpus Luteum, from the yellow appearance it
 assumes, especially in Quadrupeds
   The Corpus Luteum, consists of an outer vascular, and
 an inner Inorganic-looking Substance, which has been
 considered  by  some  authors  as the  remains  of  the
 Ovum
   The Corpus Luteum is  not found till after impregna-
 tion.  It continues during pregnancy, and for some time
 after delivery,  when it gradually vanishes,  but leaves a
 Scar in the Ovarium, which continues for life —The
 number of Corpora Lutea  corresponds with that of the
 Ova impregnated
   After the Embryo is received into the Cavity of the
 Uterus,  the Os Tinea* is shut up  by a Ropy Mucus  se-
 creted from the Follicles in the Curvix Uteri; the Men-
 strua cease to flaw.—and the Uterus b)  degrees is charg-
 ed from a triangular to an oval form.
   From the influx of Blood.'and the growth ofthe Ovum,
 the Cavity of the Uterus gradually enlarges from a size
 capable only of admitting an  Almond, to that which
 contains the full-grown Fcctus, the Secundines and wa-
 ters ; composing  together a Mass equal to nine or  ten
 pounds weight
   Some time after impregnation,  the Fundus and Body 
ire
of the Uterus, being softer and looser than the Cervix,
first yield to the par s which it Contains.
  For the two first  Months, the Uterus increases so lit-
tle as jio remain in  the Caviiy  of the Pelvis, anditii
generally after  the third  month, before  the Tumour
f'-rmed by it  can be felt above  the  Symphysis  of tht
Pubis
  1).ring the first thre« months, the  Os Tincae remajjj
smopth and even and its Onhce is nearly as im theiKl
impregnated  state: but  between, the third and  fifth
month, the Cervix and Orifice  begin to be dilated, the
former becoming  softer,  and  the  latter  changing its
common appearance,  and projecting more into  the Ca-
vi'y of the Vagina.                                ".
  the Uiems continues to rise  through  the whole£fe I
riod  of Gestation, but frequently inclines a little tojnt, ,
side.—-In the seventh  month, it reaches the  Uminus
and at last touches the Scrobiculus Cordis, Stol™A
and Colon, occupying the whole of  the Umbilical Epi-
gastric Regions. •
  In the progress of  Gestation, the whole  Uterus be-  •
comes softer, looser,  and more  Vascular,  and,the  Ves-
sels are generally enlarged,  the proportional increase
being lieai-ly.similts to chat of the Uterus.             T
  The course of the Arteries is  remarkably convolutefl.|
—fully as much so as they are  previo.us to conceptions'™
andgrea.ly more so than that of the corresponding Vek.
   The Veins are much larger than the Arteries,  then  |
diameters being such as to have distinguished  themby  |
tjhe name of Sinuses ;—-and to them the great bulk ofthe
Uierus is clncrly owing.                           .  i , jj
  The Substance of the Uterus was formerly suppose* , ]
by sonic*  to be thicker,  and by others to be thinner  m
the Gravid,  than  in  the  unimpregna'ied state ; but the
general "y of Anatomists sfr.em  now sufficiently satisfiedi
that it is nearly the same thickness in both states, and
during t,lie whole n-rm of Pivgnancy.
  In 'he latter months, the Tub^icle of  the Os Uteri is
considerably  enlarged,  and the firmness of its texture
coriv. rted  to the   Spongy softness of the Body of the
Uh'ius.  The-tiansverse  Rin-a  or  Orifice is  changed
i.-tto an oval  Pit u'.id in women who have borne several 
177
children,  it is considerably dilated  near the  end of
Gestation.
  The situation of  the Appendages of the Uterus is al-
so considerably altered.  The Ovaria, with  the Tubes
and Ligaments of  the  Uterus,  are lower situated, in
respect to the Fundus Uteri, in proportion as it ascends ;
and at the full time, the Broad Ligaments, by assisting
in forming a covering to the Uterus,  are nearly oblite-
rated.
  In  the enlarged state of the Uterus, the Muscular Fi-
bres are distinctly seen.—They form Fasciculi which run
in various directions, but cannot be traced far  wiihout
interruption
   A description is given by Ruvsch of a circular muscle
in the bottom ofthe Uterus, for the expulsion ofthe Pla-
centa;—but the Placenta is found to  adhere to  other
parts  besides the Fundus Uteri ;  nor has  such a  Muscle
been observed by  later Anatomists.
   The Muscular Fibres of  the Uterus assist in the deli-
very of the child and expulsion ofthe Placenta; and in a
few days afterwards, the Uterus partly by the contractile
power of these Fibres, and partly by that ofthe Blood-
vessels, is restored to near  its former dimensions.

     Contents of the Uterus about tbe end of Pregnancy.

   T*he contents of the Uterus, towards the end of Preg-
nancy, consist of the Fatus, the Umbilical Cord, Placenta,
Membranes, and Waters.
   The Cord, Placenta, and Membranes,  are named the
Secundiues, or After-birth, with  which  some include the
waters though these are  discharged previous  to the ex-
pulsion of the  child.
   The Cord is fixed by one end to the Umbilicus of the
Foetus, and by the other it is attached to the Placenta at
a little distance from its middle, from which circumstance
the extraction ofthe Placenta is more easily effected.
   It is commonly  about two feet long,—in some instances
more, in others less; but in general it is of sufficient length
to allow the,Birth of  the child,  while the Placenta ad-
heres to the Uterus ofthe mother.
   Its thickness is nearly  equal to that of ones finger, but
smaller and weaker at the extremity next the Placenta, 
178
   —It is seldom of a cylindrical form, being marked with
   Sulci corresponding to thfr course of its Vessels.
      It is composed of one  Vein and two Arteries, whkh
   twist about each other in a spiral direction, and are cov-
   ered by a smooth coat derived from the Membranes.
      The Trunks of the Vessels are inclosed in a Gelatintm
   Cellular Substance, which adds to the strength and elaj.
   ticity of the Cord, and allows the Blcod t" pas.* freely lib
   tween the Foetus  and  Placenta, without being in danw
   of interruption from pressure.                       3
      The Vein is much larger than the Arteries ; it is desti-
   tute of Valves, and sends off no  Branches till it reaches
   the Fcctus.
      It arises from the Substance ofthe Placenta, and after
   perforating the Umbilicus, it passes in the inferior part si
   the Ligamentum Suspensorium, to the under side ofthe
   Liver.
     The Arteries arise from the Iliac Arteries of the Fortai,
   perforate the Umbilicus, and run to the Placenta, in uw
   substance of which they divide into their ultimate Bran-
   ches, where the  Ramifications  of one Artery frequent-
   ly form large Anastomoses with those of the other, and
   both communicate with the Branches of the Vein, in the
   manner Arteries and Veins do in other parts of the Body<
     The use of the Cord is, by means of the Vein, to con-
   vey pure Bloodfrom the Placentafor the nourishment of
 \the Fcctus, and, through the  medium ofthe Ar'eries, to
- Return what is not used, in Nutrition, again to be mixed
   with the Blood of the  Uterus.—By the interventionef
   the Cord al.-;o, the Placenta is more readily extracted.
     The Placenta, so called from its resemolance to a broad
   Cake, is a spongy  mass, of a round form, occupying near
   a fourth part ofthe Ovum.
     It is about seven or eight inches in  breadth,  and up-
   wards of one inch  in thickness, but is thinner at the edges
   where the  Membranes go off.
     The t \ternai surface, or that next the Uterus, is divid-
   ed Into L< bules with dee]) Fissures, while the internal,
  or that next the Fcctus, forms a regular mass, v. hich has
   numerous large Branches of  the Umbilical  Vessels dis-
   persed upon it.
     In the Placenta  are to be observed,—on the side next
   the child, the ramifications of the Umbilical Vessels fch-jn- 
179
ing the principal part of its substance,—on the side next
tbe nother, branches of the  Uterine Arteries, almost of
the size of Crow-quills, passing in a convoluted manner
between the Uierus and Placenta, and terminating in the
latter;—Veins corresponding with these Arteries, but flat
and of great size, running obliquely to the Uterus, and, in
the substance ofthe Placenta, an appearance which has
been supposed by many Authors to be the common Cel-
lular Membrane, of a tender nature, and easily ruptured
by injection,  but which is considered by late Authors as
a regular spongy Substance, similar td that in the Bodjr
of the Penis.
   The Placenta is connected to the Uterus on one side,
by Blood-vessels, and by the Decidua, and to the Foetus
on the oth^r by means of the Umbilical Cord.
   The common place of attachment is  near the Fundus
Uteri, though it is found at different times adhering to
all the other pans ofthe Uterus, not even the Os Tinea:
excepted.
   In  the case of Twins, there is sometimes only one, but
 most frequently two distinct Placentae, adhering together
by the intervention of a Membrane in which the Vessels
ofthe two Placentae occasionally communicate with each '
other.
   There are in these cases also two distinct apartments
separated by a partition, each apartment containing its
own waters and Cord.
   The use ofthe Placenta is, to receive Blood from the
Uterus, and, according to the opinion of modern Anato-
mists, to purify it, (as  the Lungs do in the Adult), for
the nourishment of the Fcetos
   The Membranes consist of the Spongy Chorion, the True
 Cor ion,  and the Amnios.
   They form a complete but slender Bag,  which lines
the Cavity ofthe Uterus, and incloses the Foetus, Umbi-
lical Cord, and Waters.
   The Spongy Chorion is a thick opaque substance, which
adheres to the-Uterus,  and forms the outer Layer of the
Ovum,  but scarcely  penetrates between the Lobules of
the Placenta.
   Between  the Uterus and Placenta, it is less distinct
than elsewhere, being perforated there, and in some dc- 
 tpl

3f*f
 the
                        180

gree concealed by the Blood-vessels proceeding from the
inside of the Uterus.
  It has a Spongy and Villous appearance, and full of
small Blood-vessels, which can be readily injected from
those of the Uterus.
  The True Chorion,—the  term derived  from Cborw^,
company, numerous Vessels being  found  to exist in it ji
the Quadruped,—is thinner, smoother, and much dentf.:
than the former.                                   jj|
  It is connected with the Spongy Chorion as far as
edge of the Placenta, where it separates from it, is i
fleeted over the Surface of the Placenta,  which is oppo- i
Bed to  the  Foetus, and is afterwards continued over the
whole of the Cord.
  It is uniform in its texture, has  a transparent appear-
ance, adheres to the Spongy Chorion and Surface of the
Placenta, by  a delicate Cellular Substance,  and has no
Vessels visible to the naked Eye, or which can be in-
jected.
  The Armors,—so called, according to  some Authors,
from its supposed  resemblance to  a Vessel used by the
Ancients for the reception of Blood in SacrificeJr—line;
the Surface of the  True Chorion, and,  with it, is re-
flected from the Placenta upon the Cord, which it sup-
plies with an external covering.
  It is thinner, more dense,  and transparent,  than the
Chorion, to which it adheres every where by a Jelly.
  It is smooth and polished on the side next the Foetus,
and is destitute of Blood-vessels.
  The Membranes, besides  containing  the Child and
Waters,  give origin to  the latter,  and,  in the time of
Labour, assist in  opening the Orifice ofthe Uterus.
  The Waters, .called Liquor Amnii, are thinnest jrnS
clearest in  the first months, after which they acquitt'
some degree of colour and ropiness.
  The Liquor Amnii, is chiefly composed of the Serum
of the Blood.   In its natural state, it has all the chaj
racters of the Liquor Pericardii,  or of the  Liquort
exhaled from the Surfaces of other  Membranes similaj
to the Pericardium—It is supposed to be derived from
the Exhalent Arteries ofthe Amnois.
  It is proportionally greater in quantity in the first than
in the last months, but the proportion and quantity vary 
                        181
considerably in different women, and in the same women
fn different pregnancies.
  Between the  Amnios and Chorion, water is frequently
collected, but in much smaller quantity than in the Am-
nios, and is  termed False Water, 01  False Delivery-   It
it frequently discharged some time previous to the birth
of the child, without any danger.
  The liquor Amnii  defends the child and Umbilical
Vessels from the pressure of the Uterus, assists in dis-
tending the  Uterus during Gestation, and allows  the Fc?;
tus a certain degree of motion.
  In the  time  of labour, it also  assists  in  dilating  the
Mouih of the Uterus, and, by lubricating the Vagina, fa-
cilitates delivery.

               Peculiarities ofthe F*tus.

  All the Bones of  the Body, excepting a few, are soft,
yielding, and imperfect, and many ef them entirely in a
state of Cartilage.
  The- head is large in proportion to the rest of the body,
and the bones of the  Cranium are united by Membrane,
which allows the size  of the head to  be  diminished,
whereby its passage is facilitated in the time of delivery.
  Between  the Frontal and Parietal bones,  is the Mem-
brane  called Bregma, formed by the Dura Mater  and
Pericranium, which  commonly  disappears before  the
child is two years of age, the margins of the bones being
then united.
  —The other peculiarities of the Bones of the Fatus are
taken notice  of in the Description of the bones ofthe  Adult.
  There is a iarge proportion of Fluids, and the Solid*
are generally srfter  than in the Adr.lt.
  The Skin is of a bright red colour, in consequence of iti
greater degree  of Vast ularity.
  That part chiefly of the Cellular Membrane is Adipose,
which is upon the Surface of the  body;  scarcely any  F.J|
being found in  the interior parts, where it gradually ac-
cumulates as the person grows older.
  The Brain, Spinal  Marrow, and Nervous System, ate
proportionally larger, but softer.
  The Sanguiferous System, and Glandular Organs, are
larger.
     VOL.  II.              L 
                         182
   In the Eye is the Membrana Pupillaris,  which ariiei
 rom the inner margin of the Iris, and completely coiera
 die Pupil.
   It separates the Camera from each other, and is very
 Vascular.  According to Blumenbach, it keep6 the Ira
 expanded, during the rapid  Increase of tbe Ball of the
 Eye.
   The Crystalline Lens is almost Spherical, and has*
 merous Vessels dispersed upon its Capsule.         4
   The Meatus Auditorius is wholly Cartilaginous, mi
 adheres by its extremity to an imperfect Bony CirrtMLL.
 which the Membrana Tympani is placed.          »^*
 •  The Meatus  Externus, and Membrana Tympani, art
 lined by a Mucous Membrane,  which is cast off after
 Bulb.
   'i he Thymus Gland, in the Fcctus, is a large Substance
 situated in the upper part of the Thorax,  betweenjb
 Layers' of the Anterior Mediastinum.              E
   It lies  over  the Pericardium,  and occupies the sfp
 where the Aorta sends off the  Carotid  and Subclavian
 Branches, and'extends a short way into tlie fore-part of
the Neck.
   It has two long Cornua above,  and ftiio  broad Lobes be-
low, is of a pale-red colour, and  becomes afterwards of a
darker hue.                                 ""^J"
   A white serous liquor can frequently be sqiieezewfmn its
 substance ; but it bas no Excretory Duct; nor is the use
ofthe Fluid, or ofthe Gland itself, yet ascertained*
   Some Anatomists are of opinion, that the white Fluid
 is  Chyle sent by a retrogade motion from  the  Thoracic
 '•_-• ct, and that the Thymus  Gland is a DiverticHlum to
 :.ie Chyle, when too great a quantity  of Lymph is sent
 to  the Subclavian Vein.
   In the  Adult, the Thymus  Gland is so completely ab-
soibed, that scarcely any thing but Cellular  Substanct
 remains in its prace.
  The Blood-vessels ofthe Thymus are Branches ofthe
 Subclavian  and Internal  Mammary; the Nerves come
from the great Sympathetica  and Eighth Pair.
   Its Lymphatics have not yet been very accurately tra-
ced.
  The Lungs are small, firm, and of a dark-red  colour, 
                        183.
and sink when thrown into water, in consequence of tlie
Bronchial Cells having not yet received Air.
  But if Air be admitted to  them by putrefaction or
otherwise, they swim in water, in the same manner ■•<!
if Air had .been conveyed to them in  consequence of
Respiration.
  The Valve  of Eustachius is distinct in the Foetus,  but
frequently Cribriform in  the Adult, is larger in propor-
tion, and is supposed to direct the Blood ofthe inferior
Cava, immediately through the Foramen Ovale-to the
Left Auricle.                               -
  In the back-part  of the Septum, between the Right
and Left Auricles, is the Foramen  Ovale,  nearly <(ual
in size to the  Mouth of the Inferior Cava, bounded ibya
thick Muscular edge termed Annulus Foraminis Ovatis.
  Upon the left side ofthe Foramen Ovale, a Membra-
nous Valve is  placed, which allows  part ofthe Blood trf
the Bight Auricle to pass through the, Foramen Ovale.
immediately to the left one, but which.completely pre-
vents its return.                        ,:
  The Blood  going through the Foramen Ovale, assists
in keeping up the  balance of circulation between the
two sides of  the heart, till the Lungs be  ready to re-
ceive it.
  The pulmonary Artery dividesinto three Branches, the
right and left of which run to  the Lungs,  while tbe
middle one, called Ductus Arteriosus, larger than both
the other Branches,  and  its Area nearly  equal  to that
ofthe Foramen  Ovale, passes in an  oblique direction to
the beginning of the descending Aorta.
  The Ductus, or Canalis Arteriosus, forms nearly one
half of the Aorta, carries  part ofthe Blood ofthe right
Ventricle into that  Artery, without  allowing  it to pass
to the Lungs ;  and the Aorta, formed  in this manner,
receives the force  of both Ventricles,  by which  it is
more enabled to send Blood through the Umbilical Ar-
teries to the Placenta.
  The Stomach is of a rounder form than in the Adult,
and commonly contains a small quantity of a Gelatinous
Matter.
  The  Appendix Vermiformis is  larger in proportion,
and is  inserted into the extremity of tne Colon, which,
at this titns, does not project to form a proper Caecum. 
         *                184.
    The Colon, and frequently also the end of the Ilium,
   .re filled with it greenish black Faces, of a viscid consii-
   •nee, termed Meconium.
    The Liver is so large a*  to occupy both Hypochon-
  driac Regions.
    The Umbilical  Vein passes from the Umbilicus, in t
  duplicative ofthe Peritoneum, to the left Branch ofthe
  Vena  Portat, and carries the Blood from the PlacenU
  to the Liver.
    From the Trunk of the Umbilical Vein, where it ter-
  minates in the Liver, a Branch called Ductus, or Cansft
  Venosus, runs in a somewhat waving direction, and joins
  the left Vena Hepatica,  where that Vein  enters the
  Cava.
    The  Ductus Venosus is much smaller than the trunk
  ofthe  Umbilical Vein, and carries part ofthe Blood of
  the Vein  directly  to  the heart, without allowing it to
  enter the  circulation in the Liver.
   The  Umbilical  Vein sends Branches  to  the  Right
  Lobe ofthe Liver,  but is principally distributed through
 the Left Lcbe ; while the Right Branch of the Vens
 Portae carried the Blood cf the Splenic  and Mesenteric
 Arteries to the Right Lobe of the Lher.
   After birth, tlie  Left Lobe of the  Liver,  whicli was
 formerly more particularly supplied by  the Umbilical
 Vein,  receives an additional proportion of Bloodfrom
 the Vena Port arum.
   The icason why  the Umbilical Vein goes partly to
 the Cava, and not entirely to the heart, is not  under-
 stood.
   The Kidneys are irregular on their Surface being for-
 med of Lobes, each of which  consists of a Cortical, a
 Medullary part, and a  Papilla, and is covered by a pro-
per Membrane.
   The  Glandula Renalis is almost as large as the Kid-
ney, but afterwards rather diminishes than increases in
 size.
  The Bladder of the Urine is of a long form, and ex-
tends almost to the  Umbilicus.  The greater part of it
is above the Pelvis, and is more particularly covered by
tlie Peritoneum than in the Adult.
  The  Urachus, which is of a Conical form, ascends
from the bottom ofthe Bladder, between the  Umbilical 
185
Arteries, and between the Peritoneum and Line* Alba,
to the Umbilicus, and vanisjies by degrees » the Uinta-
lical Cord.                     . .  -   j   ,r  •
  It is formed by a production of the Fundus Vesicay
and in the Human Body is generally solid, forming' a
Suspensory Ligament of the Bladder.
  It has been sometimes found hollow at its beginning
and has been said to be  so, in one  or two instances,
throughout its whole length
  In the Foetal Quadruped, it is a large Tube, which
transmits Urine from the Bladder to a Bag bet ween the
Amnios and Chorion, called Allantois.
  The common Iliac Arteries divide, on each side, into
a small External, and large Internal Branch.
  The principal part ofthe Internal Iliac is occupied in
forming the Umbilical Arteries, which mount by the sides
ofthe  Bladder, on the  outside ofthe Peritoneum, and
perforate the Umbilicus in their progress  to the Umbi-
lical Cord.
   Soon after delivery, the Foramen Ovale, Ductus Ar-
teriosus, and Venosus, with  the  Umbilical  Vein and
 Arteries, begin to  contract, and are, in general, com-
 pletely closed, and the  Vessels shrivelled into  Liga-
 ments within a year after birth.
   This obliteration is produced by a contractile power
in the parts, by a pressure in the surrounding Viscera,
and by tlie Blood  being directed through other chaa.
nels.
  The Pelvis of the Fatus is commonly so small, that
the principal parts  of  its Viscera are contained in the
open Cavity of the Abdomen,
   The Prepuce of the Clitoris is proportionally so much
larger in a young Fcctus than it is afterwards, that, in  an
Abortion, a Female Fcctus has been frequently mista-
ken for a Male.
   The Tests are lodged  during the greater part of Ges-
tation, in the Cavity of  the  Abdomen, over the PsOae
Muscles, and a little below the Kindneys.
   They then  constitute a part of the  Abdominal Vis-
cera, and, in a similar manner with them, are connected
to the body by a production of the  Peritoneum, which
 forms their Tunical Albuginea.
   Bctwetn the, Testicle and  Scrotum, a FiWroua and
                         T   •> 
                          186
 Vascular Substance, of a  Conical form, is extended,-*.
 called by Mr. Hunter, Guburnaculum, or Ligamentum
 Testis, which he considers sfs a principal agent in direc-
 ting the course ofthe Testicle, and in making way for it
 in its descent.
   About the eighth month of pregnancy, the Testis, by
 means not yet completely ascertained, passes gradually
 along to the Scrotum, a process ofthe Peritoneum pre-
 ceding it,  which  afterwards forms its Vaginal Coat.
   The  Testes through the whole  of its course", contin-
 ues to be covered by the Peritoneum,  is connected to
 the parts on which it rests, and has  its Vessels passing
 to it from  behind forwards, the same as when situate!
 in the Abdomen.
   While the Testicle is passing  through the Ring of
 the  Abdominal Muscle,  the Ligamentum Testis is found
 to be in some measure inverted, and to form the under
 and fore-part of  the Vaginal Coat,  on whicli the  Crt-
 master  Muscle is expanded.
   After the descent ofthe  Testicle, the Peritoneal pro-
 cess, which descends along with it, begins to contract
 at the Ring, and a firm  adhesion of its  sides,  to within
 a  little distance of the  Testicle, is commonly  found to
 be produced by the time of birth.

                 Position of the Fatus.

   In the first months, the Embryo swims in the liqjr
 Amnii,  free from the pressure ofthe surrounding pew
 —and from many dissections and observations  madefy
 the latest Anatomists, it is ascertained,—that  the head
 preponderates, and in general continues undermost till
 the child is delivered.
   Formerly it was supposed that  the  Embryo, in the
 first months, was situated with the head uppermost, and
that, in  the latter months,.the attitude of the Foetus was
 inverted.
   The Foetus is observed to'be coiled  up into as round
 a figure as  possible, so as to be properly adapted to the
Cavity ofthe Uterus.
  The head is bent towards the  Thorax, and  the arms
are folded.—Th : knees are drawn towards the Abdo-
men, and tlie heels towards the Nates. 
isr
  The Spine is bent into an arch,  and »ne side of the
body of the Foetus is frequently turned forwards.
  The hpad  is placed diagonally, with its long Diame-
ter corresponding1 to that of the Pelvis, and the occiput
opposed to the  Os Tincae.

         Circulation of the Blood in the Fatus.

  The blood is  sent by the Arteries ofthe Uterus to the
Substance of the  Placenta,  from which according to
most of the ancient  Anatomists, it pusses to the Umbi-
lical Vein by a direct communication of  Branches ; or,
according to the opinion ofthe greater part of modern
Anatomists,—bv  Absorption.
  By the Umbilical Vein it goes r rincipally to be circu-
lated in the Liver, and by the Ductus Venosus, a small
portion of it goes to the right Auricle ofthe heart.
  The blood sent from the Inferior Cav a  is transmitted
by the l* oramen Ovale to the left Auricle, and that sent
by the Superior Cava is transmitted  to the right Auri-
cle and Ventricle, and from thence to the Pulmonary
Artery.
   From the Pulmonary Artery, one portion of it passes
thiough tlie Circulation ofthe 1.'  ngs, and another goes
by the Ductus  Arteriosus to the Aorta Descendens.
  From tbe Lungs it is returned by the Plumonary Veins
to the Left Auricle, where it mixes  with that  coming
from the right  Auricle by  the  Foramen Ovale, and is
sent by the Aorta to the different parts of the body.
  From the Iliac Arteries, it is  conveyed  by the Umbi-
lical  Branches to  the Substance ofthe Placenta, where
one portion of it returns by  corresponding Veins to the
Fatus, the rest  going to the Uterus in the manner it was
discharged from the Uterine  Arteries to the  Branches
ot the Umbilical Vein.
                      L 3 
PART V.
OF THE  ABSORBENT  SYSTEM.
          Of the Absorbents in General.

  THE Absorbent System, consists ofthe Absorbent Vet-
sels and Conglobate Glands, the former of which are di-
vided into Lymphatic and Lacteal Vessels.
  The Absorbents are small pellucid Tubes, which have
been discovered in most parts of the body,  and are sup-
posed to exist in all.
  They begin  by numberless open mouths, too minute
to be visible  to tbe  naked Eye ;  though,  by the assiv
tance of Glasses, the Orifices of the Luteals have been
seen int.ie humanbody by Mf.CauicKSHA\::, and those
ofthe  Lymphatics, in certain kinds of  Fishes, by Dr.
Mosko.—See their Treatises upon this Subject.
  They arise from the External Surface  of the body"i
from the Cellular Substance, from the Surfaces of the
large Cavities, and from tlie Surface and  Substance of
the different Viscera ;—but have not yet been observed
in the Cavity ofthe Cranium, or in the Placenta and its
Membranes.
   In the different parts  ofthe Body in general they run
in two  sets,  one superficial and very numerous, the
other accompanying  the Arteries, and at least double
their number.
   The Lacteals are  of  the same nature with the other
 Absorbents.   They begin from the inside  of the Intes- 
189
  tinesr and, when these contain Alimentary matter, they
  carry a white Fluid, called Chyle, and at other times a
  Clear Fluid or Lymph, to be mixed with the  contents of
  the Lymphatics.
   Mart of the Lymphatics, and all the Lacteals, termi-
  nate in the Thoracic Duct, by which the Lymph and
  Chyle are conveyed to the red Veins, to be mixed with
  the Blood.
   The  common place- of termination  is  in tlie large
  Veins in the bottom of the Neck;—no  facts or obser-
  vations having been yet established of their terminating
  in*any other part of the Venous, System.
   The coats of the Absorbents are thinner  arid more
 transparent, but stronger.than those of the Red Veins,
 being able to support a Column of Mercury of conside-
rable weight; but  from their thinness  they, cannot be
 enumerated.
   They are generally supposed however to be formed
 •f different Membranous Layers, like the Blood-vessels.
  Fibres can be seen in them, and their Muscularity is
  rendered probable  by the Contractile power which they
  are observed to 'misscss in a living or moribund Animal.
   By this contractility they convey their contents from
 their Origins towards their terminations, in which they
 are assisted by the  motions, of the surrounding parts, in-
 dependent of such  a Vis a te'go as contributes to propel
 the Blood through the Veins.
   Thoj are furnished with Blood-vessels for their nou-
 rishment, as sometimes observed by penetrating injec-
 tions ; and this.is rendered still m.ore evident; by their
 being susceptible of inflammation and pain-
  The presence of Nerves also appears probable from the
nentcness of their feeling when in a state of inflamma-
tion.
  In general, tliey form an irregular Net-work, having
frequent communications  with,each, other ;• and these
arc most numerous  in ^5. vicinity of their  Glands.
  Through their whole extent, tliey are .injerc^'pted by
Faliec,  which art placed in pairs, and are  of a semicir-
cular firm, haying.one <idge of each^ ^alve fixed io the
side of tlie Vessel, and the other edge" loose across its
cavity, fyiv tuvqe<d;ii)uards the ginc-ial Jeyninatiohs
  The Vahes are found, in'so me "pans, to be sftnated 
190
a,t equal distances ; in others, more irregularly.-Vrheir
number also is very uncertain, amounting in some parts
to three or four, and in others to seven or eight, or up-
wards, in the length of an inch ;—but varying still more
with respect to number, in different Bodies, and in dif-
ferent parts of the Body.
  When the  Absorbents are  destended,  they appear
largest on the side of the Valves towards their general
termination, and the enlargements are such as to give
the Lymphatics a jointed, and the Lacteals frequently
a vesicular  appearance.
  In the termination ofthe Absorbents, whether in the
Thoracic Duct, or in the Bed Veins, there  is always
one  and commonly two  Valves, to prevent the contents
of the Duct or of the Veins from passing into them.
  The use of the  Valve is to promote the general course
ofthe Lymph and Chyle, and to prevent the retrcgade
motion of these  Fluids within their Vessels.
  Use of the Absorbents: The Lymphatics take in the
Fluids applied to their orifices by the Capillary Attrac-
tion, and by a power inherent  in themselves, and by
their contractile  nature conduct them into the Mass of
Blood, whereby  they prevent morbid  accumulations.—
The Lacteals, in like manner,  receive the Chyle  from
the  Intestines for the nourishment of the Body.
  The Conglobate Glands, or  Glands of the Absorbent
Vessels, are found in various parts ofthe Body, and are
situated in  the Cellular Substance under the Skin, or
over the  Trunks of the Blood-vessels belonging to the
different Viscera :—They are of a round or Oval form,
and  frequently a  little flattened.
  They are of different sizes, from that of a Millet-seed
to that of a Substance near  an  inch in diameter ; and
sometimes several are collected into one mass.
  Their colour also varies in different parts ofthe body
and at different times of life.
  In young  subjects, they  are generally largest, and of
a redish or brown colour, but become smaller and pa-
ler  with increasing age ; and  immediately  under the
Skin, they  are reder and  firmer tlun within the  large
Cavities.
  They hate a smooth, dense,  Membranous Covering, 
191
which give them a shining appearance, and are connec-
ted to the surrounding parts by loose Cellular Substance.
  Their Coat  is connected  to the Glandular part by a
Cellular  Membrane, which according to Dr. Hali.er,
is pervaded by a Succus proprius full "of Globules, which
Mr Hew son supposed, afterwards  form the Red Glo-
bules ofthe Blood.
  Like oilier Glands,  they have  Arteries, Veins, and
Nerves, entering their composition.
  They arc described  by  some Anatomists, as being
composed of Cells internally, while  others consider them
as bcirg a Congeries of convoluted Absorbent Vessels.
Most ofthe Glands have much of the former, but many
of the in of  the latter appearance.
   1 he Absorbents entering into the Glands, are called
Vas Inferrutia.  When they  approach,  or come  in con-
tiict w'nb the Gland,  they split into radiated Branches,
which, after spreading over it, penetrate  into its  Sub-
stance.
   Ihe greater part of the  Absorbents, approaching a
 Gland, terminate in it in this manner, while others turn
 aside, or go over it, and terminate in other Absorbents
 or in other Glands.
   From the opposite side of the Glands, vessels go out
in the manner they entered it, and are termed Vasa Ef-
ferentia-   They are frequent y, though by no means al-
ways, fewer in number, but larger than the Vasa Infer-
entia.
  Most ofthe Absorbents go through  several Glands,
but in some parts through one only, before they reach
their general terminations.
  The Lymph and Chyle  are strained  through  the
Glands,  by which they are supposed to undergo  certain
changes,—but the nature of these changes has  not yet
been ascertained.


             Ofthe Particular Absorbents.

  The Superficial Absorbents of the  Lower Extremities,
consist of numerous vessels, which lie between the Skin,
and Muscleti. 
192
   They belong to the Integuments in general, and ar«
 much more  numerous  than the  Subcutaneous Red
' Veins.
   They can be traced from the Toes, round which they
 form a Plexus.
   From the Toes, several Branches, likewise forming a
 Plexus, run over the top of the  Foot to the inner part
 ofthe L  g, and from that  along the corresponding part
 ofthe Knee.                                          ,
   From the outer part of  the Foot, another Plexus a-
 rises, which runs along the outside of the  Leg, where
 it splits into two divisions, one of which crosses obliquely
 over the fore-part of the  Tibir, to the Lymphatics at
 the inner side of the Knee.
    The  other division  pulses partly to the Political
  Glands,  some ascending upon the  outer and back-part
 ofthe Thigh.
    The Political Glands are commonly  two  or  three in
 number, and are situated  near the  Artery  of *he same
 name, but frequently they are  so smutl und so much
 turied in Fat, as to be discovered with difficulty.
    From  the Sole, another Plexus of Lymphatics arises,
 and joins these upon the Leg already described.
    From  the  inside  of the Knee a Pl-.:xus runs up, con-
  sisting of from twelve to twenty Trunks, which pass af-
 terwards on the fore aud inner part of the Thigh to  tlicjv
  Groin.                                             *
    The greater  part of the Trunks of the Plexus, ac-
  company the Vein called Sapheiia Major,  and in their
 passage  they receive many small branches from  tht '
 outer and back-part ofthe Thigh.
    In the Groin, they split  into Branches  which pene-
  trate the Inguinal Glands.
    The Ing-tiual Glands  are  generally from six or eight
  to a dozen in number., and ai e  of very different sizes ;
  but sometimes the number is smaller, in consequence of
  two or more of them being united into one  large Gland.   <
    Ofthe Inguinal Glands, some lie in ihe an^ie betweeu
  the Thigh and  Abdomen, and others a few inches fai>
  ther down  on the  fore-part of the Thigh.
    The greater  number are placed upon the outer  part  •
  of the Tendinous Aponeurosis, the rest deeper, bein^
  in contact with the great B^oeid-ve-Jbeitr. 
193
  The Superficial  Lymphatics of the  Thigfc jenter the
lowest of these Glands ; one or mdre ofthrniVhowevei',
frequently pass by the first Glands they meet with, and
penetrate others higher in the Groin,  and sometimes a
few do not enter any Glands till they go into the Abdo-
men.
  Into the Inguinal Glands enter likewise the superfi-
cial Lymphatics ofthe upper and back-part of the Thigh
with those ofthe Nates and ofthe Abdomen and Loins.
  The deep-seated Lymphatics ofthe Lower Extremity afe
situated  among  the   Muscles.—they  accompany  the
Blood-vessels and are few in number  when compared
with the Subcutaneous set.
  In several places, one only has been yet observed on
each side ofthe Trunks ofthe Arteries, thongh, in o-
thers, they are  somewhat more  numerous, forming a
Plexus over the Blood-vessels.
  They arise from the sides of the Toes, and from  the
deep parts of the  Sole, accompanying  the Plantar  Ar-
teries; and after reaching the  Leg, they run up with
the posterior Tibial Artery to the Ham.
  In the Ham,  they lie close  upon the Trunk of the
Artery, and enter the Political Glands.
  Besides these, there are similar but smaller Lympha-
tics, which begin upon the upper part of the Foot,  and
afterwards  accompany the anterior Tibial,  and the Fi-
bular  Arteries, receiving Branches from the deep parts
ofthe fore and outer-side  ofthe Leg.
  The anterior Tibial and the Fibular Lymphatics,  ter-
minate with the posterior Tibial in the Glands  ofthe
Ham.
  From the Political Glands, two and sometimes more
Trunks of considerable size are sent out, w hich accom-
pany the Femoral Artery,  and  at different  distances,
which communicate with each other, by Branches which
pass obliquely across the Artery.                   f
  At the upper part of the Thigh, they enter the under-
most ofthe Inguinal  Glands, where the Lymph of ihe
superficial and deep-seated Absorbents of the Limb Is
mixed and incorporated.
  The superficial Lymphatics of  the Scrotum enter the
upper and inner Inguinal  Glands, those deaper seated 
194
passing with the Lymphatics of the Testicle into the
Abdomen.
  The superficial Lymphatics  of the Penis begin at the
Prepuce, and form a lew Trunks v» hich run principally
upon  the  Dorsum  Penis,  receiving in their passage
Branches which turn round from its inferior surface..
  In some Subjects, they unite into trunks in the mid.
die of the Dorsum  Penis,  which  afterwards sepanfc
into- right and left parts.
  In others, they are more unconnected, and in all they
appear to divide at the root of the Penis into right and
left Branches, passing into the corresponding Inguinal
Glands, wh ch lie next the Symphysis ofthe Pubis.1
  The deep-seated Lymphatics of the Penis arise from the
Glans, and from the Body of trie Penis, and accompany
the Arteries into the tinder part of the  Pelvis.
  The Lymphatics ofthe Testicle are numerous, and ire
among the largest ofthe Body some of them exceeding
the size of a Crow-quill.
  They arise from the Coats and  Body ofthe Testicle,
and from the Epididymus, and run with  the Spermatic
Cord through the  Ring of the Abdominal Muscle, to
terminate in the  Lumbar Glands.—In their passage,
they have few communications with each other.
  The Lymphatics of the external parts of Generation if
Women,  go partly to the Inguinal Glands of each side,
and  partly through the Rings of the external oblique
Muscles, in company with  the round Ligaments ofwe
Uterus, and terminate in the  Iliac or in the Lurihf
Glands.
  The superficial Lymphatics  of the under part qflk
Abdomen, those  of the Loins, Nates, and verge of the
Anus, pass into the Inguinal Glands, each set termias-
ting in such ofthe Glands as  lie nearest parts to which
the Vessels belong.
  The Inguinal Glands, having  received the  Lympha-
tics of the Inferior Extremity, and likewise the superfi-
cial Lymphatics of the external  parts of Generation,
•end  out Trunks fewer in number, but considerably
large  than those which entered the Glands.
  The Vassa Eficuntia of the  Inguinal Glands enter
the Abdomen under Povfaht's Ligament, in company
with the Inguinal and Iliac An cry. 
195
  Some of them go into  the Glands situated about the
Iliac or the Lumbar blood-vessels.   The Iliac Glands
jare frequently almost as numerous as the Glands of the
Groin, and one of them  is generally found larger than
the rest, and placed at the inner edge of Poupart's Li-
gament.  The Lumbar Glands are more numerous than
any of the  classes already described, and are placed
over tbe Abdominal Aorta, Inferior Cava, and bodies of
the Lumbar Vertebrx.
  The rest of the Lymphatics from the  Lower Extre-
mity descend at the side ofthe Pelvis, near the Inter-
nal Iliac Blood-vessels, and pass through some of the
Glands which are situated there.
  The last-mentioned  Lymphatics are joined by absor-
bents from the viscera ofthe Pelvis in general, especi-
ally by those ofthe Bladder and Vesicular Seminales in
the Male, and by a portion of those of the  Uterus and
ofthe Vagina in the Female.
  The  Lymphatics ofthe Bladder, in both sexes, accom-
pany its principal Blood-vessels, pass through some small
Glands upon the side of it, and, at the under part ofthe
Pelvis, go into the Glands which surround the Internal
Iliac Artery and Vein.
  The Lymphatics of the Uterus run in two Sets j one,
which  is the largest, goes with the Appogastric, the
other with the Spermatic Blood-vessels.
  Tbe  Hypogastric Lymphatics form a Plexus which runs
from above  downwards,  into Glands situated  on the
sides of the Vagina.
  From these  Glands {hey pass  to others which sur-
round the  Internal Iliac  Vessels, and then intermixing
with the Trunks  from the extremities,  they terminate
in the Thoracic Duct.
  The  Lymphatics,  corresponding with the Spermatic
Vessels, terminate in the Lumbar Glands, as in the
Male.
  The  Lymphatics ofthe  Uterus, like its Blood-vessels
are much enlarged and of consequence easily discovered,
in the Gravid state.
  The  Lymphatics  ofthe Rectum go  first  into  small
Glands which  lie between it and the  Os Sacrum, and
afterwards terminate in the Lumbar Plexus ot Glands
and Vessels,. 
196
   Besides the  Lymphatics  which lie on  the  inside of
 the external Iliac Artery, there are others situated on
 the outside of it, upon the Psoas Muscle.
   Of these, one part passes  up to  the Lumbar Plexus,
 and goes under the Aorta, in different Branches which
 terminate in the Thoracic Duct.                   «
   Another part passes under the Iliac Arteries, and ajjt
 pears upon the Os Sacrum, forming a remarkable Pkf
 us, which goes through many Glands, and is chieiy sitt
 ated behind the Aorta and Vena Cava.
   The Lacteal Vessels, so called from conveying a fluid
 like milk, which is termed Chyle, begin upon the inner
 Surface  ofthe Intestines.  Each Lacteal  takes its ori.
 gin upon one of the  Villi, by numerous short radiated
 Branches, and each Branch  is furnished with an Orifice
 for imbibing the Chyle.
   From  the Villi the Lacteals run a considerable way
 under the Muscular Coat of the  Intestines, and-then
 pass obliquely through them, uniting in their course in-
 to larger Branches.                           •
   They follow the direction of the  Blood-vessels, and
 their Trunks are double the number ofthe Arteries,—
 one being situated on each side of them.
   Upon the outside ofthe Intestines an external set ap-
 pears.   They run between the Peritoneal and MuscuUi
 Coats, and commonly placed someway in  the directioo
 ofthe Intestine, and with a  few ramifications.
   The Superficial and deep-seated Lacteals com mini-
 cate in the Substance ofthe Intestines, and,, after kjfr-
 ing them, commonly form a Plexus, which runs betvfeeo
 the plies ofthe Mesentery and  Mesocolon, without^-
 lowing the course of the Blood-Vessels.
   The Lacteals ofthe Jejunum are larger and more nu-
 merous than those ofthe Ilium, the principal part of the
 Chyle being contained in this Intestine.
   In their course, they pass through a great number of
 Lacteal or Mesenteric Glands, which like  the Lacteals
themselves, are largest and most numerous in that part
ofthe Mesentery which belongs to the Jejunum.
  The Mesenteric Glands are seated in the  Fat between
the Layers of the Mesentery,  near the Branchings af
 the Blood-vessels. 
197
  They are commonly scattered over the Mesentery,  at
a little distance from each other ; but there are seldom
any  observed within two or three inches  ofthe Intes-
tines.
  They are of different sizes in different parts of the Me-
sentery, some being about a lialf, or two thirds of an iac.h
in diameter, while others are so small as to be traced with
difficulty.
  Their Structure is  the same with that of the Absor-
bent Glands in  other parts of the Body, but tliey are ge-
nerally flatter, and are of a white colour when tilled with
the Chyle.
  They are considered by some Authors as dividing the
 Lnctcals into different Orders.
  From the Intestines to the Glands,  the  Lecteais are
called  Vassa Lactea Primi Generis, and from the Glands
to the Thoracic Duct,  Vassa Lactea Secundi Generis.
  Some  divide them  into three Orders ;—the first con-
sisting of those which go from the Intestines to tlie
Glands,—the second of those which run from one set of
 Glands to another,—and the third, of those which pass
 from the Glands to the Thoracic Duct.
  The Lacteals of the  small  Intestines, after passing
through the different Glands ofthe Mesentery, form atlast
one, and frequently two, three, or  more Trunks, which
accompany the Trunk of the superior Mesenteric Artery,
till  they arrive at the right side of the Aorta, where they
sometimes pass into the Thoracic Duct: At other times
tliey descend a little, and join the Trunks from the Infe-
rior Extremities, to  form that Duct.
  The Absorbents ofthe Great are of an Inferior size in
proportion to those of the Small  Intestines, f rid  have
seldom, though sometimes, been observed  to  be filled
With Chyle.
  In their course they go through the Mesocolic Glands,
whicli  are situated between the Layers of the Mesoco-
lon, but are generally much less numerous  and conside-
rably smaller than those ofthe Mesentery, or of most o-
ther parts ofthe Body.
  The Absorbents ofthe Cxcum, and ofthe right portion
ofthe Colon, join those ofthe Small Intestines, about the
teot of the Mesentery. 
198
   Those of the left portion of the  Colon accompany the
 Inferior Mesenteric Artery, and communicate with large
 lymphatics near its Root
   They terminate at last in the Lumbar Glands, or go
 directly into the lower part of the  Thoracic Duct
   Of the Absorbents of the Stomach, one set runs upon
 its small, and another upon its great Curvature, but nei-
 ther the one nor the other are found  to carry Chjk,
 Chough a few have been observed filled  with  it in other
 animals,—as the Dog.                              {
   The former of these i composed  of Branches from (hi
 upper and under surfaces  of the  Stomach, accompas
 the Superior Coronary Artery.
   In their passage, they go through a few small Glandi  '
 situated at  the junction of the Omentum Minus to tbe
 Stomach, and,  after becoming larger they enter other
 Glands in company with the deep-seated Lymphatic! of
 the Liver,  along with which they terminate in the 1k>
 racic Duct.
   The other set passes from  the great Curvature of the
 Stomach, partly to  the right, and partly  to the left side,
 and, as on the small Curvature, are formed of Branches
 from its opposite Surfaces.
   Those on the Left side receive the Lymphatic* of the
 middle and  corresponding half of  the OmentunP-Majus.
 Running to the left side of the large  Curvature of tbe
 Siomach, and passing through one or two small Gland'
 on it,  they  go  with the Lymphatics of the SpleevaMJ
 Pancreas to the Thoracic Duct.
   Those of the right side receive the Lymphatics of ute
 corresponding half of the great Omentum, and also pass
 through one or two small Glands which lie close to d«
 right Gastric Artery.
   In their descent by the Pylorus,  they meet the Plexhs
 which accompany the superior Coronary Artery, and run
 with them, and with the deep Lymphatics of the Liver to
 the Thoracic Duct.
   The Lymphatics ojTthe  Liver, as  in other Viscera, run
 in  two sets, the superfical of  which are numerous,  and
 unite into Trunks in the manner Roots unite  to form the
trunk of a tree.
   The Superficial and deep sets communicate so freely
 (hat upon injecting  the Lymphatics en tlie external syr- 
199
face, tlie deep-seated Absorbents are readily filled from
them.
  The principal part ofthe Lymphatics upon the convex
Surface of the  Liver, go by  a right and left Plexus to-
wards the Suspensory Ligament.
  Running along this Ligament they directly perforate
the Diaphragm, after which they pass through Glands si-
tuated upon the anterior part of the Pericardium.
  Other Lymphatics from the convex part ofthe Liver
run towards the lateral Ligaments, where they  form on
each side one or more Trunks of considerable size.
  From the lateral Ligaments they pass through the sub-
stance of the Diaphragm, and afterwards run forwards on
its convex Surface, following the direction ofthe Ribs.—
Not unfrequently, these Vessels, instead of perforating
the  Diaphragm, run downwards and terminate in the
Thoracic Duct, within the Abdomen.
  In their course upon the Diaphragm,  they often send
Branches backwards, which  terminate in Glands upon
the Esophagus—in  ether instances, these Branches are
observed to go directly into the Thoracic Duct.
  They receive Branches from the Substance ofthe Dia-
phragm, and after perforating two or three  Glands upon
its Surface; they join the Trunks from the Ligamentum
Suapensorium. ,                         '
  Tbe Lymphatics from the  lateral Ligaments, joined
by  those from the Ligamentum Suspensorium, form
either a principal Trunk, or  a Plexus,  which runs  up,
sometimes between the  Layers ofthe anterior Mediasti-
num, and at other times, in  company with the  internal
Mammary Blood-vessels on each side.
  When this trunk or Plexus runs in the anterior Medi-
astinum, it most frequently terminates in the upper end
ofthe Thoracic Duct;—sometimes,  however,it commu-
nicates with the general  termination of the right side of
the  Neck.
  When they accompany the internal Mammary Vessels,
they are observed to terminate, the  left  in the Thoracic
Duct, and the  right in  the general termination of that
side.
  The Lymphatics on the concave Surface of the Liver
run towards the  Porta, and join the deep seated Set.
—One part of  them goes over the under Surface of  tbe
     VOL. II.            M       ' 
200
1

Gall-bladder, from which they receive numerous small
Branches.
  The deep-seated Lymphatics accompany the Blood
and Biliary Vessels, and communicating with the Super-
ficial Absorbents already  mentioned, they pass through
several Glands situated about the Trunk ofthe Vena Por-
t'ac, and terminate in the Thoracic Duct, near the root of
the superior Mesenteric Artery.
  The Superficial Lymphatics of the  Spleen are remar-
kably small.   They pass from its convex to its concave
Surface, where they  join the deep-seated Lymphatics,
which are very considerable in size and number.
  The  Splenic Plexus of  Lymphatics  accompany the
Splenic Artery, and go through several Glands of a dark
colour scattered along the Surface of that Vessel.
  The Lymphatics of the Spleen  receive those of the
Pancreas, which run into them in a transverse directiA
  In their course, they unite with the  Lymphatics ofljjft \
Stomach and those descending from the under part onW   '
Liver; and the whole of them, near the head ofthe Pan.
creas, form a considerable  Plexus. From  this  Plexui,
Branches are sent off, some passing over the Duodenum,
and  others under it, and all of them going into  the Tho-
racic Duct near the termination ofthe Lacteals..
  The Lymphatics of the Kidney are seldom seen/excep-
ting when it is enlarged or ulcerated, in which case they
may sometimes be distinctly observed.
   The Superficial Absorbents run from its outer towards
its inner edge,  where, meeting with  those  deep-seated,
they commonly unite with them, and form a Plexus which
accompanies the Renal Blood-vessels, after which they
pass through some of the Lumbar Glands, and terminate
in large Lymphatics near the  Aorta.
   The Lymphatics of theCapsula Renalis, which are nu-
merous in  proportion to  its  size, terminate in the Renal
 Plexus.                                           *
   All the Absorbents already described, excepting those
from the convex Surface of the Liver,  terminate in the
Thoracic Duct near its beginning.
   The  Thoracic Duct, at  its under extremity, is formed
by the  union of three, or sometimes of more principal
 Trunks, tire first of whicli is composed ofthe Lymphat-
 v oi tl. - right, and the iccond of those of tlie left infer- 
                       201
ior Extremity-^-the third Trunk, or set of  Trunks, be-
longs chiefly to the Lacteals.
  These large Absorbents unite so as to form the Duct
over the third Vertebra of the Loins.       *
  Sometimes they unite upon the second Vertebra ot
the Loins,  where the Duct formed by them is twice or
thrice as large in diameter as it is higher up.
  Commonly it enlarges again upon  the first Vertebra
ofthe Loins, where it has generally been called the re-
ceptacle ofthe Chvle and considered as the beginning
 ofthe Duct, being'often found forming an  oval, or Py-
 riform Bag, about the third of an inch in diameter.
   These large Trunks which form the Thoracic Duct
 lie close upon the Spine, those of the right side being
 placed  below the right Crus of  the Diaphragm,  and
 those ofthe left between the Aorta and Spine, while the
 Thoracic  Duct itself lies at  first behind the Aorta,
 but afterwards passes from it upwards, and a little to the
 right side, till  it gets before the fii3t Vertebra ofthe
  Loins.
    Here it is situated behind the  right Crus ofthe Dia-
  phragm,  a little higher than the right Renal Artery,
  from whence it passes upwards, and afterwards appears
  in the Thorax, upon the fore and right side ofthe Spine,
  between the Aorta and Vena Azygos, where  it is sup-
  posed to be considerably  assisted by the  strokes of tlie
  Aorta in impelling its Fluids.
    In the middle of the Thorax,  it is smaller than else-
  where,  being only about a line in diameter.  After this
  it gradually enlarges, and, near its termination, is about
  an eighth or tenth of an inch over.
    In the  Thorax, it receives the Lymphatics  of the
  Spatia Intercostalia, one or two  of  which accompanies
  each of  the Intercostal  Arteries,  and  the  whole go
  through small Glands  placed near these  Arteries, but
  most numerous about the. sides ofthe Dorsal Vertebrae
  whore they form a sort of chain.
    Here,  likewise,  it receives Branches from the Eso-
  phagus and Lungs, the  former  of which is surrounded
  with a number of' Glands, and with a remarkable and in-
  tricate Plexus Of Lymphatic Vessels.
    The Superficial Lymphatics  of the Lungs form large
  Arcolx,  which have smaller Areola: within them,  tho 
                       202
larger running chiefly between  the  Lobules,  and the
smaller passing over them in such a  manner as to cover
almost the whole Surface of the Lungs.
  From the surface they go to the root of the Lungs,
where they pass through the Bronchial Glands, which
have already been taken notice  of in the descriptionof
the Lungs.
  At this placethey are joined by the deep-seated Lym-
phatics which creep along the Branches ofthe Trachea  J
and of the Pulmonary Blood-vessels.                  1
  Through the medium of the  Bronchial Glands, the  1
Lymphatics of the two sides of the Lungs communicate  1
freely with each other.                           <   1
  Having left the Glands, the principal part  of those   j
from the left Lung form a trunk of considerable  siae,
which terminates in  the Thoracic Duct behind thehi>  j
furcation of the Trachea.                             i
  The rest of the Absorbents  of the left Lung pM    j
through Glands behind the  Arch of  the  Aorta, whttk    j
are likewise common to those ofthe Heart. They run
at last by a principal Trunk into the Thoracic Duct near  ,
its termination.                                     ,
  After leaving the Bronchial Glands, the Absorbenfsof  1
the right  Lung form a  few principal  Trunksi one of
which commonly ascends on the fore part of the Vena
Cava Superior, and, running in a convoluted manner,
opens into the Trunk which terminates  in the Veins in
the right side ofthe Neck.
  The rest of these Trunks go into the Thoracic Duct,
near the bifurcation of the Trachea.
  The Absorbents of the Heart are small, but numerous,
and form principal Trunks which accompany the Coro-  /
nary  Arteries, and, like them, the largest belong to the
left Ventricle.
  Erom the side ofthe right Coronary Artery, an Ab-
sorbent Trunk whicli corresponds with it, passes over
the  Arch of the Aorta to a Gland commonly found be-
hind  the origin  of the Carotid  Arteries.
  From this Gland it goes afterwards to the general
termination in the right side ofthe Neck.
  The  Lymphatic trunk accompanying the left Coro-
nary Artery is formed of two principal Branches, one of
which runs in the Groove between the Ventricles on the
superior Surface ofthe  Heart: The other runs in a si-
milar Groove on the under side of the Heart, and hav- 
                       203
ing reached the space between the Auricles and Ven-
tricles, turns  round to join the former Branch near its
corresponding Artery.
  The Trunk runs next  to a Gland placed behind the
Pulmonary Artery, between the arch of the Aorta and
root of the Trachea, which, with the others here situa-
ted, is common to the  Absorbents of the  Heart and
Lungs.
  This trunk  terminates at length in the upper end of
the Tnoracic Duct.
  The Thoracic Duct, after receiving numerous Lym-
phatics within the Thorax, and having reached as high
as the third or fourth Dorsal Vertebra, passes obliquely
over to the left side of the Spine, behind the Esopha-
gus and end of the arch of the Aorta, or beginning of
the Aorta Descendens, till it reaches the  left Carotid
Artery.
   After this, it emerges from the Thorax, and runs be-
 tween the  Longus Colli  Muscle and Internal  Jugular
 Vein, to about the sixth Vertebra of the Neck.
   It now makes a turn downwards, and, after descend-
 ing near an inch, terminates in the upper and back part
 of the angle formed by  the left Internal Jugular and
 Subclavian Vein.
   Throughout its whole course, it has a waving appear-
 ance, and  this becomes  more conspicuous in proportion
 as it is distended by injection.   Near the middle of the
 Thorax, it not unfrequently splits into two or more bran-
 ches, and sometimes forms a Plexus,  the Branches of
 which again unite into a  common trunk a little higher up.
   After emerging from the Thorax, it  commonly di-
 vides into  two parts, which unite again previous to the
 termination of the Duct  in the red Veins ; and where
 there is no division, there is generally  a Dilatation or
 Sac at the termination.
    Sometimes there is one termination in the angle for-
 med by the red Veins, and one or two in the Subclavian
 Vein, and now and then, though more seldom, in the
 Internal Jugular, near  the angle.
    In a few instances, it has been found double through
 its whole length, one Duct going to the common place
 of termination in  the left side of the Neck, and the o-
 ther in the corresponding part in the right.
                        M  2 
204
    It has also, in a few rare instances, been found termi-
  nating in the Veins in the right, side of the Neck, while
  a short trunk, similar to that commonly found there, has
  terminated in the left side.
    The Superior, in a similar manner  with the Inferior   .
  Extremities, have two  sets  of Lymphatics, one  lying   \
  immediately under the Integuments,  and belonging to   ,
  the Skin and  Cellular Substance under it, the other ac-
  companying the principal Blood-Vessels, and belonging
  to the parts deep-seated.
   The Superficial Lymphatics are numerous,  and rea-   j
  dily seen in emaciated Subjects.                       J
   They arise from the fore and back-parts of the fingers  ■
  and hand, by a considerable number of Branches, and
  form  an extensive Plexus upon the corresponding sides
  ofthe Fore-Arm.
   Those upon the anterior part of the Fore-arm run
  directly upwards to the Arm, while the Lymphatics on
  its back-part, separate into two sets, one of which pas-
  ses obliquely over the Muscles on the anterior part of   3
  the Fore-Arm.                                       j
   The Lymphatics of the Fore-Arm run over the bend-  I
 ing of the elbow, and afterwards ascend upon the fore    I
 and inner part ofthe Arm, the greater number of them
 running near the Basilic Vein.
   Some of them frequently  pass through small Glands    '
 placed along the Humeral Artery, one of which is com-
 monly found a little above  the inner Condyle  of the
 Os Humeri, others do not appear to  enter any Glands
- till they reach those of the Axilla.
   A few Lymphatics accompany the Cephalic Vein, and
 receive Branches from the outer part of the arm, and,   i
 after passing  betw'een the Pectoral and Deltoid Mus-
 cles, penetrate Glands at the under side ofthe Clavicle.    f
   Of the deep-seated Lymphatics, two commonly ac-
 company each principal  Artery in the Fore-Arm, and
 these uniting at the elbow, form two principal Lympha-    1
 tics, which accompany the trunk of the Humeral Arte-
 ry.
   Having reached the upper part of the arm, they en-
ter the Axillary Glands, where they are joined by Lym-
phatics which come from the Mamma and lateral parts
of the  Thorax, after passing through small Glands pia- 
205
ced upon the under edge ofthe former and of the large
Pectoral Muscle.
  The Axillary Glands vary in number and size in dif-
ferent persons.  They are somewhat smaller, and fewer
in number than those of the Groin.   They are generally
surrounded by a considerable quantity of Fat, and are
situated in the hollow between the large Pectoral and
Latissimus Dorsi  Muscles, adhering closely to the
Trunks of the Axillary Blood-Vessels and Nerves.
  From the Axillary Glands large Branches go under
the Clavicle, and form a Trunk, which in the left side,
commonly joins the Thoracic Duct near its termination.
In the right side, they join the short Trunk which forms
the second general termination of the Absorbent Sys-
tem.   Sometimes this Trunk, proceeding from the Su-
perior Extremity, terminates in the Subclavian Vein, at
a little distance from the  general termination.
  The Axillary Glands  receive also the Subcutaneous
Lymphatics from the back-part of the Thorax, and like-
wise the Lymphatics from the  Integuments and Mus-
cles of the Scapula.
   The Lymphatics on the outside of the Head accompa-
ny the Blood-vessels, and pass through Glands in their
way to the Neck.
   Those passing down with the Temporal  Artery  go
through small Glands connected with the Parotid Gland,
and also through others situated immediately under the
root ofthe Zygoma.
   The  Lymphatics  which  accompany  the Occipital
Blood-vessels penetrate one or two minute Glands pla-
ced a little behind the root of the ear, over the Mastoid
Process ofthe Temporal Bone.
   The Lymphatics proceeding from the different parts
of the Face accompany the Branches and Trunk of the
Facial Artery.
   Some of them pass through Glands situated upon the
outside of the Buccinator  Muscle, while the principal
Trunks  go through a number of large Glands placed
upon the outer, and also at the under part of the Lower
Jaw, at the anterior edge ofthe Masseter Muscle, and
about the Inferior Maxillary Gland.
   The Lymphatics from the inner part of the Nose run
principally with the  internal Maxillary Artery, and pass
                        M 3 
206
 through Glands situated behind the Angle of the Lower
 Jaw, where they  are joined by those which  belong.,to
 the inner parts of the Mouth.
   The Lymphatics of the Tongue, and likewise of the
 Muscles and other parts about the Os Hyoides, enter  ,
 the Glands placed behind the angle ofthe lower Jaw.
   Lymphatics have been frequently searched for in the
 Brain, but their existence in that Organ is not yet fully
 ascertained, though rendered highly probable,—from  an
 appearance  of Lymphatics having  been  now and then
 observed "opon the surface of the Dura Mater, and be-  ]
 tween the Tunica Arachnoides and Pia Mater,—from
 Lymphatics and Glands being occasionally found in,  or
 immediately on the outside ofthe passages ofthe Blood-
 vessels ofthe Brain,—from swellings in the Lymphatic
 Glands ofthe Neck, following diseases ef the Brain,—
 from the Absorption of Water,  which has sometimes
 happened in Hydrocephalus cases, and from  their hav-
 ing been found on the Brain of Fishes.
   From the superficial and deep part of the Head  in
 general,  the Lymphatics accompany the External and
 Internal  Jugular  Veins and the Carotid Arteries, re-
 ceiving at the same time Branches from the Muscles
 and other parts of the Neck.
   The principal part of these Lymphatics go along with
 the Internal Jugular Vein and Carotid Artery, and in
 their passage form a remarkable Plexus,  which goes
 through the numerous  Glands seated near the Blood-
 vessels, composing a chain, from which they are termed
 Concatenat*.
   The Glandul* Concatenat* are more numerous  than
 any other set of Glands  in the Body, excepting those
 which belong to the Mesentery.
   The Cervical Plexus of Lymphatics  having passed
through the Glandulae Concatenatae, unite at the bottom
ofthe Neck into a trunk,  which in the left  side, enters
the Thoracic Duct near its termination, and in the right
goes into the trunk, which forms the general termina-
tion of tliat side.
   The trunk which forms this general termination  is
 only from a quarter  to half an inch in length, but its
size not much less than that of the Thoracic Duct. 
207
  It is formed by Lymphatics from  the  right side of
the Liver,  Diaphragm, Heart,  and the right Lobe of
the Lungs, by those ofthe right Arm, right side ofthe
Head, Neck, and Thyroid Gland ; the Lymphatics of
the left side of the Thyroid Gland forming a trunk
which ends in the Thoracic Duct.
 Besides this common Termination, some of these Lym-
phatics occasionally open into the Internal Jugular, or
into the Subclavian Vein,  at a little  distance from the
angle formed by these two Veins.
M  4 
PART  VI.
                 OF THE

BLOOD-VESSELS IN GENERAL,
The Blood-Vessels  are divided into Arteries and Veins.

                    Arteries.

 The Arteries are elastic Canals, which convey the Blood
from the Heart to the different parts  ofthe Body, and
are distinguished from the Veins by their Pulsation.
  They have obtained their name from the Ancients,
supposing that they carried the finer parts ofthe Blood
mixed with Air,—forming what  they considered the
Animal Spirits.
  The Original Trunks ofthe  Arteries, or those which
arise from the Heart, are two in number, viz. the Pul-
monary Artery and Aorta,—all the others being derived
from these.
  They are dispersed over the whole Body, and every
where surrounded  with Cellular Substance.
  The principal trunks run in  the Centre of the Body, or
of the Extremities, where they are least exposed to dan-
ger,—deriving support or defence from the Bones along
which they pass
  The largest  Arteries go to the  Viscera,  within the
great Cavities, the  smaller ones to the Skin and Mus-
cles, and those still smaller to the Bones,—and,  in a few 
209
 places,  they become so extremely minute as altogether
 to exclude the red Blood, carrying a colourless Fluid
 only.
   The Arteries are distinguished, in the Subject, from
 the Veins, by the whiteness of their Colour anil thickness
 of their coats.
   They are composed of different Layers or Coats which
 are readily separated by dissection.
   In several parts of the Body, as in the Posterior Me-
 diastinum, they are surrounded  by a Membrane, com-
 mon to them and to the neighbouring Viscera.
   In other parts ofthe  Body, especially in young Snb-
■ jects, they are surrounded with so much Cellular Sub-
 stance,  as to  give them the appearance of being inclo-
 sed in Sheaths.
   The first of the proper  coats  is the External Mem-
 branous, or Cellular, called also by some  Authors the
 Nervous Coat.
   In the large Arteries, this coat is frequently furnish -
 ed with Fat, and is of a very elastic nature.  Owing to
 this  elasticity, the  Arteries,  in • receiving  the  Blood
 from the  Heart,  become dilated and elongated, and'
 start from  their place,  in  consequence of which they
 form the Pulse, called also the Diastole ofthe Arteries.
   The Second, or  Middle  Coat,  is composed of Fibres
 running in a transverse direction,—of a pale red colour,
 —each Fibre  appearing to form only the Segment of a
 Circle, although the whole constitute a cylinder round
 the Artery.
   By the Contractility of this, and the elastic nature of
 the former Coat, the Arteries are enabled to drive the
 Blood to the Veins, in proportion  as they receive it from
 the Heart ;—and  this contraction is  called  the Systole
 ofthe Arteries.
   The Third, or Inner Coat, is formed of a transparent
 Membrane, remarkably thin,  smooth, and  dense, by
 which theBlood is prevented from transuding.
   The different coats ofthe Arteries are connected to
 each other" by fine Cellular  Substances,  which some
 Authors have considered as so many Lamellae.
   The Arteries are  supplied with their own Blood-ves-
 sels, termed Vasa Vasorum, which come from the near- 
                       210                        I
er small Branches, and are every where dispersed upon '
their external Surface.
  They have also their Lymphatics, which, on the large
Arteries, as the Aorta, are so numerous as sometimes J
to cover them.                                     *
  They are likewise furnished with small Nerves, for-
ming, in some parts of the Body, a Plexus, which va-
nishes in their external coat.                         )
  There are no Valves belonging to the  Arteries, ex- j
cepting those which are placed at the mouths of the
Pulmonary Artery and Aorta.                        I
   Where the Arteries run a certain way without sending t
off Branches.they are observed to be of ^Cylindricalform;
but where Branches come off, their Capacity is diminish-
ed, and this in proportion to the number of  their Rami.
fixations.
   Whenever an Artery divides into two Branches, the
Areae of these two Branches, taken conjunctly, are found
to be nearly one half larger than that of the Trunk from
which they issue-
   When the Trunk and Branches of  an  Artery are're-
garded collectively, they appear evidently of a Conical
figure, the point of the Cone being formed by the trunk, .
and the Basis by the Branches ofthe Artery.         (
   The Section ofthe Arteries is circular •—when empty,'
they become flat, but recover their round form upon be-
ing distended by injection.
   The  angles  at which the Branches go off from their
Trunks are in general in proportion to their vicinity to
the Heart, and are such as  are most favourable to the
parts they have to supply.
   In the trunk of the Body, or where they belong  to
tender and delicate Viscera, the angles are more obtuse;
in the  extremities, they  are  more acute, the former
circumstance tending to diminish, and the latter to in-
crease the force of the Blood.
   The Arteries form  many  Divisions and Subdivisions
before  they reach their Terminations, and at  last be-
come invisible to the naked eye.
   The Divisions formed by any particular  Artery have
been variously enumerated  by different Authors,—one
reckoning them at forty, and another, of equal respecta-
 bility, at twenty only ;—the number of them, however, 
                          till
   is  such as to allow them to supply the most minute'
   parts ofthe Body.
     The  strength of the Arteries depends upon the thick-
   ness of their coats, which is found  to vary in  different
   Arteries.—In the Aorta, the coats are thick and strong;
   —In the Arteries ofthe Brain and Spleen, they are thin
   and tender ;—but the thickness and consequent strength
   are proportionably greater in the small Branches than
   in the large trunks.
    The Arteries run more or less in a waving direction,
\  which breaks the force of the  Blood in  them,  and pre-
   vents them  from being  strained by the motions of the
,"  parts to which  they belong.
    The Flexions are  most frequent in Arteries belonging
   to parts the size and situation of which are changeable.
    The windings of many of  the Arteries are in propor-
   tion to  the degree in  which they are distended, those
   which  are nearly  straight  in their natural state, fre-
   quently becoming serpentine when their distension in-
   creases.
    Several of the large Arteries form communications
I  with each other, termed by Anatomists Anastomoses;
   but  the Anastomoses  are  more  frequent  among the
   small Branches, where they form  a  Plexus  which les-
✓  sens the danger of the obstruction.
;   The Anastomoses are most frequent in the Skin and
|  Membranous Parts.  In the solid Viscera, the  Arteries
   run in a different manner, being in some crowded toge-
   ther in the form of Trees or Bushes, in others having a
,  serpentine appearance, and  in several forming Penicilli,
;  or little Brushes, according to the  disposition of the
   part.
■;   The Arteries obtain their particular names from their
i  situations, place of destination, cJ*c. and the term Captl-
F  lary, as  expressive  of their smallness, is applied  to
  (their minutest Branches.
    The Diameters ofthe different Trunks and Branches
  ofthe Arteries, vary much in different parts ofthe body*
  but  thise of the Capillaries are more nearly  equal to
  each other.
    The  Arteries terminate  in  the  following  manner,
  viz. 
                        212
., n red Veins, as is observed by the assistance of tlie
  'croscope and by Injections :
  In Glands or Follicles by  Secretory Ducts, which se-
Parate a Fluid from the general Mass of Blood.
  In exhalent vessels, which discharge tlieir  contents
•nto the internal Cavities, or upon the  external Surface
ofthe Body.
  In colourless or Lymphatic Branches, which are af-
terwards continued to the circulating Veins, as in the
Cartilages and Cornea.
  The use ofthe Arteries is :
  To convey Blood from the Heart to the different parts
of the Body:
  To assist in converting the Chyle into Blood :
  To nourish the Body, and promote its growth :
  To assist in preserving the fluidity of the Blood, and'
the heat and life ofthe Body :
  To form the different Secretions : and
  To renew the growth of  parts destroyed by accide
or disease.

                        Veins.

   The  Veins are  elastic flexible Tubes, returning the
 Blood from the different parts ofthe Body to the Heart,
 —and have no pulsation.
   The  Coats ofthe Veins are the same in number with
 those ofthe Arteries, but are thinner, denser, and less
 elastic-
   ln the  large Veins,  as the Vena Cava, the coats can
 be separated from each other;—but in the small Bran-f
 ches their separation is difficult.
   The Muscular Coat of the Veins being much thinner,
 loose like Cellular Substance, and more indistinct than
 that of the ATteries, has occasioned its existence to  be
 denied by many Authors.
   The Veins are also furnished with their Vasa Vasorm.
 similar to and from the same source with those of the
 Arteries.
   The Colour ofthe Veins  is somewhat blue, and when
 full of Blood they appear of a purple tinge, in  conse-
 quence of their thinness. 
213
     Their Size is more than double that of the Arteries to
   which they belong, excepting the Pulmonary Veins, the
   size of which scarcely surpasses that of their corres-
   ponding Arteries.                             r
     In the fleshy parts of the Body, particularly  in  the
   extremities, they consist of Two Sets, one deep-seated
,   accompanying the Arteries, the other running immedi-
   ately under the Skin, and termed Subcutaneous.
r    Tlie Veins of the  Thoracic and Abdominal Viscera in
r  general, accompany their Arteries ;  and the same is ob-
■  servable in the small Branches belonging to Membranous
   parts.
     The Figure ofthe Veins is similar to that ofthe Arte-
   ries ; and upon comparing the Area of their Trunks with
   the collective Arexof their Branches, like them too, they
   are perceived to be conical, the base  of the Cone being
   formed by the Branches and the Apex by the Trunks.
     The size and number ofthe Veins is so much greater
   than that of their corresponding Arteries,  that when the
   vessels of a membranous part are distended by an Injec-
'   tion of different colours, the Veins are observed in a great
   measure to conceal the Arteries—In the Intestines, how-
   ever, the  number of the Arteries and Veins  is nearly
s   equal.
*    There is  much greater variety among the  trunks of
It  Veins, with respect  to situation and division into branch-
   es, than is observable among the Arteries.
,.    The variety in Nature is such, that the Veins of every
   Subject differ a little from those of another.
I    The Veins are  capable of suffering  greater  distention
   than the Arteries, yet are more frequently ruptured.
     The  Anastomoses are greater and more frequent in
   Veins than  in Arteries, those of the former  being fre-
   quently by large Trunks, whereas those ofthe  latter, ex-
   cepting in afew places, are by small branches only.
     Where the Veins are exposed to Muscular action, they
   are furnished with  Valves, which are semilunar Folds
   continued from the  inner side ofthe Vessels and placed
   in pairs at irregular distances, their nature being similar
   to those ofthe Absorbents.
     The Valves are concave towards the Heart,  and when
   close or applied to each other, present a figure somewhat
   like that ofthe shut end of a thimble. 
214
  Between the Valves and Sides of the Veins next the
Heart,  the blood insinuates, and Cavities  are' formed,,
termed Sinuses of the Valves, which appear  externally ■
in the form of Varices.
  The Valves are found in the fleshy parts of the Body
in general, but are chiefly situated in  the  Veins of the#j
Extremities.
  They are a wanting in the Veins of the deep-seated
Viscera, viz.  in those ofthe Cranium, Thorax, and Ab.™
domen, excepting the Spermatic Veins, and  sometimes'
the Internal Mammary Veins, and the Branches ofthe
Vena Azygos.
  The Valves direct the Blood towards the  Heart,
and prevent Regurgitation.
  The use of the Veins is :
  To convey the Blood from the extremities ofthe
teries, with the Chyle and Lymph, from the  Absorb
to the Heart.
ie Ar-
DISTRIBUTION OF THE BLOOD-VESSELS,

      Ofthe Pulmonary  Artery and Veixs;

  The Pulmonary Artery arises from the right Ventricle j
of the Heart,  and  ascends behind tlie Sternum, andj
within the Pericardium, inclining a little to the left.    j
  Having run as high as the concave side of the Archj
ofthe Aorta, it divides into right and  left lateral Bran-
ches, which terminate in the corresponding sides ofthe
Lungs.
  The right Branch passes behind the curvature ofthe
Aorta and the superior Vena Cava, and is of course the
longer of the two.
  The two Branches are dispersed throughout the sub.
stance of the Lungs, by ramifications which accompa-
ny those ot the Bronchi.
  From the extreme Branches ofthe Pulmonary Artery,
the Blood is returned by corresponding Veins.
  The Pulmonary Veins run contiguous to the Arteries, 
                       5515
and unlike the other Veins in general, are nearly of the
same size with their Arteries.
  In their course, they unite into larger Branches, which
at length form four principal Trunks,—two from the
right, and two from the left Lung,—which after perfo-
rating the Pericardium, terminate 'in the left Auricle of
the Heart.

      General Course of the Aorta and Vena Cava.

  The Aorta arises from the left Ventricle of the Heart
and sends off, at its Origin, the Coronary. Arteries for-
merly described.
   Where it takes  its origin, it turns a little to the right,
and is afterwards directed upwards, backwards, and to-
wards the left side.
   It ascends as far as the top of the Thorax, under the
name of Aorta Ascendens, and is afterwards reflected ob-
liquely backwards over the root of the left Branches of
 the 1 rachea, forming what is termed Curvature or Arch
 ofthe Aorta.
    It then commences Aorta Descendens, which runs down
' close upon the Spine, till it reaches the fourth Vertebra
i °f the Loins, where it divides into the  two Iliac Arte-
Iries.
I   The Thoracic portion ofthe  Aorta Descendens is si-
Ituated on  the fore and left part ofthe Spine, between
  the Layers of the Posterior Mediastinum.
    Where it passes from the Thorax to  the Abdomen,
|  it goes between the long Crura of  the Diaphragm, after
I,  which  it descends more immediately upon the forepart
^Of the Vertebra*.
,    The Aorta sends off  Arteries  which carry Blood to
  the different parts of the  Body,  from whence it is re-
  turned by the Veins to the Inferior and Superior Vena
  Cava,—excepting what passes to the Coronary Vessels.
    The  Inferior Cava is formed by the union ofthe two
  Ven* Iliacae, upon the last Vertebra ofthe Loins, a lit-
  tle below the Termination ofthe  descending Aorta.
    It V, situated upon the fore-part ofthe Spine,  and at
  the right side of the Aorta, which it accompanies  fur
  a considerable way through the Abdomen. 
216
   Near the upper end of the Abdomen, it recedes from
 the Aorta, and passes  behind the large  Lobe ofthe
 Liver.
   It perforates the Diaphragm in  its Tendinous part,,
 and having entered the Pericardium, it goes immedi-
 ately into the right Auricle of the  Heart.            *
   The Inferior Cava receives the Blood from the Inferior
 Extremities, from the  Pelvis and Abdomen, and carries'
 it to the Heart.
   The Superior Cava,—formed by t!he union of the two
 great Venae Subclavian with the addition of the Vena-
 Azygos,—is situated in the upper part  of  the Thorax,,
 upon the right side of, and a little more anteriorly than
 the ascending Aorta.
   It begins behind the Cartilage of the  first Rib, some.;
 what higher than the arch  ofthe Aorta, and ha3 at first
 a small inclination towards  the right side.
  After descending about an inch, it perforates  the Pe-
ricardium, and having run down nearly twice this space, I
it enters the right auricle, opposite to the termination of
the Inferior Cava.
  The Superior Cava receives the Blood from the Head,
Neck, arms, and containing parts of the Thorax, andabo
carries it to the Heart.
 BLOOD-VESSELS of the HEAD,  and

     PART or THOSE of the NECK.


                    Arteries.


  From the upper side of the arch of the Aorta,  Three
Large Arteries arise, which supply the Head, Neck, and
Superior Extremities.
  Of these three Arteries, one on the right side, termed
Innominata,  soon divides into  the  Right Carotid, and
Right Subclavian Artery. 
217
  The other two are the Left Carotid, and Left Subclavian,
which come off in separate Trunks.
  Carotid Arteries : The Carotid Arteries, after emerg-
ing from the Thorax, run up on  each side of the Neck,
between the  Trachea  and Internal Jugular Veins, and
behind the Sterna-mastoid Muscles, gradually  receding
from each other.
  In the Neck, they do not send off any  Branches till
they reach the top of the Larynx, where  each, opposite
to the Os Hyoides, divides into  External and Internal
Carotid Arteries;  the former supplying the outer parts of
the Head, the other the Brain.
  The External Carotid is placed more anteriorly, and
nearer the Larynx than the Internal, which lies deeper,
and is at its root, the larger ofthe two.
  The External, though smaller than the other, appears
as a continuation ofthe common Trunk.
   It runs up behind the angle of the Lower Jaw, and in
its passage before the Ear towards the Temple, is sunk
deep in the  substance of the Parotid Gland,  which it
supplies with Blood, and is divided into the following
principal Branches, viz.
  The Arteria Laryngea Superior, Gutturalis Superior, or
Thyroidea Superior, which comes off from the root ofthe
external Carotid, and sometimes from the top of the com-
mon Carotid.
  It passes downwards in a  winding direction, and sends
  Branches to the Muscles about tlie Os Hyoides ;—
  To the Muscles, Jugular Glands,  and  Skin near the
Larynx;—-and
  To the different parts ofthe Larynx itself, the continua-
tion and  principal part of the Artery terminating in the
Thyroid Gland.
   The Arteria Lingualis, which is sent off immediately
above the former.—It  goes  forwards and upwards over
the corresponding Cornu of  the  Os Hyoides, and under
the Hyo-glossus  Muscle, in a direction towards the un-
der and fore-part ofthe Tongue.—It gives
   A small Branch to the Pharynx;—
   A Branch,  termed  Ramus Hyoideus, to the  Muscles
 placed between the Tongue and Larynx ;—
   The Dorsalis  Lingua to the Fauces, Aimgdala, E; .
lottis, &c—
      vol.. II.             K 
                      .  218
   The Ramus Sublingualis, which comes  off under the
 middle ofthe Tongue, and is dispersed upon the Sublin-
 gual Gland and adjacent Muscles;—and
   The Ramus Raninus, which is the principal Branch of
 the  Lingunl Artery, running al the tinder and lateral part
 of the Tongue, and terminating near its point.
   The Arteria Facialis, Maxillaris Externa, Labi alts, or
 Ahgularis, which  also runs forwards, and goes under
 the  Stylo-hyoid, and Tendon of the Diagastric Muscles.
 It perforates the Submaxillary Gland, mounts suddenly
 Over the angle of the Lower Jaw, at the under and  fore- '
 part ofthe Maseter Muscle, from whence it proceeds in
 a tortuous manner towards the inner coiner of the Eye.
   In this course, it sends the following Branches to the .
 adjacent parts.
   Tbe Palatina Inferior, which runs  upwards upon the ,
 side ofthe Pharynx.—
   A Branch to the Tonsil, Sec-
   Branches to the Inferior Maxillary Gland ;—
   Small Branches to the  root of the Tongue, to the
 Skin,  Muscle s, &c. near the angle of the Jaw ;—
   The A. Submentalis, which  runs forw ards under the
 Base of the  Lower Jaw,  furnishing Branches to  the
 parts near it, andterminatingon the middle ofthe Chin :
   Upon the outside ofthe Jaw,—a Branch to the Mas-
 seter Muscle;—
   While upon the Buccinator Muscle,—Branches to the
 Check and to the lower part of the under Lip ;—
   Near the qorn'er ot the mouth,—the A.  Coronaria Ii-\
ferior to the under Lip ;  and a little higher,—
   The Coronaria Superior to the upper Lip, from whence^
 Branches run  to  the under part of the  Partition  and
 Point of the Nose.
  The  Coronary  Arteries run near the edge ofthe lips,
 where meeting with  their fellows of the opposite side,
 ttfey form an A. Coronaria Labiorum.
   Frequently one or both Coronary Arteries are larger
 than ordinary, in which case those on  the opposite  side
 are proportionally smaller.
   After sending offthe Coronary Branches, the Facial
 Arterv runs near the wing and side ofthe Nose.
   From this part ofthe Artery,  Branches are sent in-
 wa.'fts  to the Nose, and outwards,to the Cheek'.
  T he  Facial  Artery  is at last lost upon the parts about 
219
  the inner corner of the Eye, and  middle of the Fore-
  head.
    The Pharyngea Inferior, which is a small Artery aris-
  ing near the Lingual  Artery,  and frequently from the
  root of the Occipitalis.
    After ascending some way,  it divides into Branches,
  which are dispersed  upon the  Pharynx, Fauces, and
  Base of the Skull, where some of them'enter the large
  Foramina, and supply part o£the Dura Mater.
    The  A. Occipitalis, which arises from the back-part
  ofthe External Carotid, and at  its origin is concealed
  by the other original Branches sent offfrom that Artery.
    It run6 over the beginning of the  Internal Jugular
  Vein, and afterwards passes under the Mastoid Process,
  and posterior Belly ofthe Digastric Muscle.
    It goes likewise under the upper ends ofthe Trachelo-
  mastoideus,  Splenitis, and complexus Muscles;  after
  which, it becomes  more  superficial, where it runs near
  the middle ofthe Occiput.
    In its course, it is very tortuous, and gives off differ-
  ent Branches to the surrounding Muscles : viz.
    One which descends along the Sterno-mastoid Mus-
  cle, and communicates with the 'Thyroid, Cervical, and
  Vertebral Arteries:
    Another which passes, with the Jugular Vein, to the
  under and back-part of the Dura Mater :
    A Twig, through the Foramen Stylo-mastoideum, to
  different parts ofthe Internal Ear :
    A Branch which proceeds to the back-part of the ear,
  under the name of Auricularis Posterior /—and
»<■   Another of considerable size, which  descends be-
• tween the Trachelo-mastoideus and Complexus Mus-
  cles, and, after bestowing Twigs upon several Muscles
  ofthe Neck, communicates with the Cervical and Ver-
  tebral Arteries.
    The Artery is at last  dispersed  upon  the beginning
  ofthe Occipito-frontalis  Muscle, and Skin of the Occi-
  put, where it communicates with its fellow, and with tbe
  Temporal Artery.
    Sometimes, a Twig of this Artery passes to the Dura
  Mater, through that small hole occasionally found near
  the Mastoid Process ofthe Temporal Bone.
    The A.  Maxillaris Interna, which goes off from that 
                       220                          ;
part of the Trunk which is covered by the Parotid Gland,
and at its origin lies behind the middle of the upright
Plate which divides into the Condyloid  and Coronoid
Processes ofthe Lower Jaw.
  It passes first between the Jaw  and External Ptery-
goid  Muscle, and afterwards runs  in a very  winding  ,
manner, towards the back-part of the Antrum Maxillare,
sending numerous Branches to the parts belonging to
both Jaws.              *
  At its origin, it furnishes Twigs to the fore-side and
adjacent parts of the outer Ear.                        '
  It then sends off the A. Dur* Matris Media Maxirhi  ,
Meningea,  or Spheno spinalis, which runs between the  ■
Exterfial and Internal Carotids, passes through the Fo-
ramen Spinale ofthe Sphenoid Bone, and spreads over
the Surface ofthe Dura Mater and inside of the Pari-
etal Done, like the Branching of a Tree-'
  The Inferior Maxillary Branch, which runs in the In-
ferior Maxillary Canal,  sending Branches  to  the sub-
stance of the Bone, and to the Teeth ;—the remainder
of it passing out at the Anterior Maxillary Foramen,
and communicating upon the Chin with  Branches of
the Facial  Artery.
  Branches to the Pterygoid, Masseter, and inner part of
fhe Temporal Muscle, under tlie names of A. Pterygordea,
Masseteric*, and Temporales Profund* .-
  The A. Buccales to the Buccinator Muscle and other  j
soft parts of tlie Cheek.                               J
  The A. Alveolares, which run behind the Antrum, and  I
send Branches to the  soft parts surrounding the Upper  1
Jaw.—-The Maxillary Artery  sends other Branches,  \
w'hich enter by small Holes to the Antrum, and to the
Substance  and back teeth of the Jaw ; one of which is
larger than the rest, and is the Proper Alveolaris.
  The Infra-orbitar, which passes in the Canal under
the Orbit, giving, at its entrance, Twigs to the soft parts
in the bottom of the  Orbit, and  in its progress, other
Twigs to the Antrum, Substance ofthe Jaw, and Fore-
Teeth ; after which it  goes  out  at the Foramen Infra-
orbitarium, and terminates on the cheek by small Bran-
ches Which communicate with those ofthe Facial Artery.
  The Palato-maxillary Branch, which passes through
the  Foramen Palatinum Posterius, and runs  between
the Osseous and Fleshy  parts of the Palate, supplying 
                       221
these with Branches, and frequently proceeding through
the Foramen Incisivum to the inner part ofthe Nose.
  The Superior Pharyngeal,  which is  a small Branch
terminating in and about the upper part ofthe Pharynx.
  The Large Lateral Nasal, which enters the  Foramen
Sphenopalatinum,   and divides into many Branches
which supply the greater part ofthe inside of the Nose.
  A. Temporalis.—The Trunk ofthe External Carotid,
having given off the Arteries already mentioned, passes
up between the  Meatus Auditorius and root of the Zy-
goma, and forms the Temporal Artery, named also Tem-
poralis  Externa* or Superficialis;—from the root  of
which are sent off,
  The  Transversalis Faciei,  which proceeds forwards
 under the Zygoma, supplying a  large portion of the
 Cheek, and communicating  with  the  Facial and Infra-
 orbitar Arteries :
  Some small Branches to the Articulation ofthe Jaw :
   Several small Branches  to the root of the  Ear, part
 of which are dispersed upon the External Meatus and
 Membrana Tympani,—some Twigs penetrating as far
 as the inner Ear.
   A little above the root  of the Zygoma, where the
 Pulsation ofthe Temporal Artery can be felt,  and fre-
 quently even seen, it divides into two large Branches,
 an Anterior, and Posterior, which are placed superficial-
 ly between the Integuments of the Head and Aponeu-
 rosis ofthe TemPorsd  Muscle.
   The Anterior Branch proceeds forwards,  in a serpen-.
 tine direction, to tbe side and upper-part of  the Fore-
k head, supplying the Skin and Muscles near  it, and com-
» municating with Branches ofthe Facial and Ocular Ar-
 teries, andwith those  of its Fellow on the opposite side
 of the Head.
   The Posterior ascends obliquely backwards, giving a
 few Branches to the upper part of the Ear,  but is chief-
 ly  dispersed on the Integuments and Muscles upon tlie
 lateral  part  and  crown of the Head, communicating
 with its fellow of the same and of the opposite side, and
 also with the Occipitalis, by numerous Ramifications.

                Internal Carotid'Artery.
   The  Internal Carotid,—sometimes termed  A Cerebri
                         N  2 
                        222
 Us,—is arched back at its origin, and then ascends in a
 waving direction on the fore-part ofthe Rectus Capitis
 Anterior Major Muscle, as far as the Foramen Caroti-
 cum, without giving offaiy Branches.
   At the Base ofthe Cranium, it makes a sudden turn
 forwards, and enters the Carotic Canal of the Tempo- (
 ral Bone ;  While  in the Canal it  passes upwards and
 forwards like the Canal itself, and is  surrounded by a
 considerable quantity of Cellular Substance, and by the j
 Dura Mater, which form a Cushion between it and the
 Bone.
   After leaving the Canal, it again bends upwards and
 then forwards, by the side  of the  Sella  Turcica ; and
 perforating the Dura Mater, at the root of the Anterior
 Clinoid Process, it is suddenly reflected obliquely back-
 wards and  upwards,  after which it divides into Bran-
 ches
   Through the whole of its course,  it runs in a serpen-
 tine manner, which prevents the Blood in it from rush-
 ing too quickly and forcibly upon the tender Substance
 ofthe Brain, and, contrary to the nature of other Arte-
 ries.—it is of a  Conical form, though  it does not send
 off any Branches till it enters the Cranium-
   While at the Side of the Sella Turcica, it furnishes
 small Twigs to the Dura Mater and parts adjacent, one   i
 of which passes  through the Foramen   Lacerum to  the 1
 Orbit, and, another,  accompanied by  a  similar Twig J
 from the Meningeal Artery, through the Pars  Petrosa,
 to the Tympanum.                                  ^
   As soon as the Carotid perforates the  Dura Mater, H
 at the root ofthe Clinoid Process, it transmits         M
   The Arteria Ophthalmica, which is the principal Ar- m
 tery belonging to the Eye and its Appendages.          ™
   The Ophthalmic, or Ocular Artery,  immediately af.  i
 ter it comes off from the Carotid, enters the Foramen
 Opticum, and creeps under the Optic Nerve, included
 in the Dura Mater, towards the outer part of the Orbit.
   After proceeding some way through the Orbit, it tra-
verses its Cavity, taking a Spiral direction towards the
Nose, between the Optic Nerve and Muscles in the up.
per part of the Orbit.
  In this course, it first transmits Filaments to the Dura
Hater and Substance of the Optic Nerve, and to the be- 
223
gimiing of the Muscles in the bottom of" the Orbit, after
which it gives off the following Branches, viz.
  The Arteria Lacrymalis, which runs at the outside of
the Orbit, and is chiefly  dispersed  upon the Lacrymal
Gland, some Threads advancing to the Eye-lids :
  The A. Centralis Retina,  which penetrates the Optic
Nerve  a little  behind the Ball of the Eye,—runs in the
Lentre of the  Nerve, and spreads out into many small
Branches upon the inside of the Retina.
  When the Nerve is cut across, the orifice of the  di-
vided Artery is  observeable, which, before its nature
was understood, was long known  by the name of Porus
Opticus.
  In the Adult, the Central Artery appears to terminate
entirely upon the Retina ; but in the Foetus, after furnish-
ing, at the bottom of the Orbit, the Branches proper to
the Retina,  the Trunk is  continued forwards through
the Axis of the Vitreous   Humour, supplying its Cells
and Membrane with delicate  Filaments, and afterwards
spreading out upon the back-part of the Capsule of the
Lens.
   Its Branches are dispersed upon the Lens in a radia-
ted manner, and after surrounding >', some of them arc
sent forwards to the  Membrana 1 upillaris.
  The Arteri* Ciliares,—two or sonic-times more innum-
ber,— which divide into Branches running in  a serpen-
tine direction along  the  opposite  sides of the Optio
Nerve, and  dividing  into the  Ciliares Breves, and Cilia-
res Longx.
  The Ciliares Breves, or Posteriores,—formed not only
of Branches from the original Ciliary Trunk, but also of
Twigs from the Muscular Branches,—are numerous.
They perforate the Sclerotica, near the insertion ofthe
Optic  Nerve, give Twigs to that coat, and dividing in-
to still smaller Branches, creep forwards upon the Tu-
nica Choroides,—forming  many  Communications with
tacli other as they advance, and retiring gradually from
the convex  to the concave surface of this coat  to supply
the Iris and Ciliary Processes.
   The Ciliares Long*, — which seldom  consist of more
•ban two Trunks,—perforate the Sclerotica a little far-
'.lu.r torwaids than the former, pass along the Choroid 
                        ''24,                         t>

coat to its anterior part, and then separate  into  Bran- fi
ches.
  Besides the Ciliares Breves et Longrc, there is anoth-
er set, termed Ciliares Anteriores, which are a few Arte-
rious Filaments li-om the Muscular Branches, entering
the eye where the straight Muscles are inserted.
  At the root ofthe Iris, the different  sets of Ciliary
Arteries unite into niches, which form an irregular cir-
cle,  called Circulus Iridis.
  From this circle, many Arteries run upon the Iris, in
a radiated serpentine manner, towards  the  Pupil, near
which several of them also unite into Arches ; and from
these Twigs ate sent, along with the rest ofthe radiat-
ed Branches, to the inner edge ofthe Iris.—In the Frr-  j
tus, they are continued to the Membrana Pupillaris.
  'The Muscularis Superior, and Inferior, which are dis-
persed upon the Muscles and Fat of tlie Eye.
  The  OEthmoidaiis Anterior, and Posterior,  two ex-  i
tremely small Twigs, especially the latter, which pass
through the Foramina Orbitaria Interna,— Anterius, et
Posterius,—to the Bones and Membranes ofthe Nose.
  The  Supra-orbltalis,  or  Frontalis, which, emerging
from the  Socket, passes through  the Foramen  Supra
orbitorium, and is divided into two parts ;—one disper-
sed  upon the Periosteum of the Fore-head, the other  1
running to the Skin and Muscles on the Fore-head and  I
upper eye-lid,  and communicating with the  anterior  m
Branch ofthe Temporal Artery.                        I
  Tlie remains of the Ocular Artery are  continued to  ■
the  inner angle ofthe Eye, and are dispersed upon tlie  ■
Eye-lids, Lacrymal Sac, side ofthe  Nose, and Frontal
Muscle, communicating with the upper end of the Fa-
cial  Artery.

                 Arteries ofthe Brain.

  The Arteries ofthe Brain consist ofthe two Internal
Carotids, and the two Virtebrals.
  Each Internal  Carotid,  after sending forwards the
Ocular Artery, gives a Branch backwards to the Verte-
bral, termed A. Cammunicans,  and then divides into the
A. Anterior, and A. Media Cerebri.
  'The Anterior Cerer.ri, turns towards its fellow ofthe 
225
opposite  side, and commonly sends  Filaments to  the
first and second Pair of Nerves.
  A little before the union of the Optic Nerves,  the
right and left anterior Cerebral Arteries become almost
contiguous,  and anastomose  by means of a  short,  but
large transverse Branch, which forms part of that com-
munication of vessels termed  Circus Arteriosus IVillisii.
  From the transverse Branch, but more frequently from
She Anterior Cerebral  Artery near it, a  Branch is sent
off, which passes into the third Ventricle, and furnishes
Twigs to the Septum  Lucidum,  and fore-part of  t\\p
Fornix.
  The Anterior Cerebral Artery  ascends upon the in-
jier side of the Anterior Lobe of  the Brain,  and sends
off a principal Branch and commonly another soon after
?-<>th of which arch backwards upon the  inner flat sur-
face ofthe Hemisphere.
  The continuation of the Anterior Cerebral Artery is
termed A. Corporis Callosi, and is  reflected back upon
the union ofthe Corpus Callosum  and Hemisphere, as
f.ir as the posterior Lobe ofthe Brain.
  The Branches of the Anterior  Cerebral Artery  are
divided into minute Ramifications,  which are first spread
out upon the flat surface of  the Hemisphere,  and  af-
terwards upon its upper part.
  The Ramifications form  numberless  Anastomoses
with each other upon the surface  ofthe  Brain, and af-
terwards pass, by minute Filaments, into its Cortical  and
Medullary Substance.
  Uesides the Anastomoses of the different Branches
of this Artery on the suriace ofthe Hemisphere, small
Branches run across  the Corpus Callosum, and inoscu-
late with those ofthe opposite side.
  The Arteria Media Cerebri,—which is larger than  the
former,—runs outwards in  a  lateral  direction through
the  Fossa  of Sylvius, to the outer part ofthe Brain.
  It gh'es first Filaments to the GlandulaPituitanaand
parts  adjacent to it, and  then divides  into principal
Branches, of which one set  go to the  Anterior, and  the
other to the Lateral  part of the Posterior Lobe ofthe
brain.
  From this  Artery, one or two Twigs, run up into  the
                        N  4 
226
 Anterior Cornu of the Lateral Ventricle, and assist in
 fqrming the Choroid Plexus of that Cavity.
  Upon the outer surface of the Brain, the Branches of
 this Artery inosculate with each other, and with those
 ofthe Anterior Cerebral Artery, and  thert  plunge into
 the substance of the Brain, where they meet with the
 deep Branches of that Artery.

                  Vertebral Arteries.

  The two Vertebral Arteries,—which are only a  little
 smaller  than the  Internal  Carotids,—arise from the
 Subclavian Arteries at the bottom of the Neck.
  Each of them,, at a smnll distance from its origin, en-
 ters the Canal formed for its reception by  the six up-
 permost Cervical Vertebrx.
  It ascends through the Neck, nearly in a straight di-
 rection, sending Twigs outwards between the Vertebrx
 to the deep Muscles ofthe Neck, and others which pass
 inwards to the Spinal Marrow and  its Membranes, by
 the Holes which transmit the Spinnl Nerves.
  Immediately below the Head, it gives out more con-
 siderable Branches to the deep Muscles at the back-
 part of the Neck, which inosculate with  the Occipital
 Artery.
  At the upper part of the Neck, it forms contortions  \
 somewhat similar to, and  answering the same  purpose
 with those of the Internal Carotid Artery.             ■
  One turn is formed upwards and outwards,  in pass-  ■
 ing from the third to the second Vertebra ; and another
 outwards and forwards, in going between  the second
 Vertebra and Atlas.
  After perforating the Atlas, it bends suddenly back,
 and runs in an Horizontal direction in  a Notch  upon
 that Bone.
  Having reached the Foramen  Magnum Occipitis, it
turns upwards, perforates the Dura Mater, and enters
the Cavity ofthe Cranium.
  After entering the Cranium, it passes with the Me-
dulla Oblongata, upon the Cuneiform Process ofthe  ]
Occipital Bone, inclining tow aids its fellow on the other
side, and at  the beginning of the. Medulla,  the two   ]
Veriebrals  unite into the Trunk called Basilar Artery. 
227
   Upon entering the Skull, each Vertebral Artery sends
a small  Branch, termed A Meningea  Posterior,—to the
posterior part ofthe Dura  Mater.
   It then disperses.Twigs to the Medulla Oblongata, and
frequently gives off the small Branch  which forms the
Posterior Artery of the Spinal Marrow.
   Near the part where it unites with its fellow, it sends
down the Anterior Artery of the Spinal Marrow.
   From the Vertebral, or from the Basilar, or sometimes
from each a principal Branch is sent off, named A. Cere-
belli Posterior,  or  Inferior, which passes  between the
Cerebellum  and Medulla Oblongata, and furnishes bran-
ches to tlie under part of the  Cerebellum, to  the back-
part ofthe Medulla Oblongata and Tuber Annulare, and
forms the Choroid Plexus ofthe Fourth Ventricle.
   The Basilar Artery runs  along the middle ofthe Tuber
Annulare, which it slightly impresses,  and lies upon the
Cuneiform Process ofthe Occipital Bone.
   From tlie sides of this Artery, numerous Filaments run
<t raneversely, to be dispersed upon the Tuber and adjacent
•jKirts.
   One Branch, larger than the rest, called Auditoria In-
terna, passes between the  two portions of the Seventh
Pair of Nenes to the Internal Organ of Hearing.
   At the extremity ofthe  Cuneiform or Basilar Process
ofthe Occipital Bone, and at the upper and fore-part
of the Tuber Annulare, the Basilar Artery divided in-
to tour principal branches, two to each side,  and these
go off almost at right angles from the Trunk, viz.
   The  A. Superior, or Superior Cerebelli, which turns
round the Crura Cerebri,  expands its Branches upon
the upper part  of the Cerebellum,  and  sinks into its
substance, supplying also  the Nates, Testes,  and Parts
near them.
   The  Arteria Posterior Profunda Cerebri, which sends
Twigs to the  1'uber  and to the Crura Cerebri, and
unites with the  Internal  Carotid by-the Arteria com-
municans.
   It supplies also parts lying near the third Ventricle,
and afterwards turning round the Crura  Cerebri, pas-
ses between the Cerebrum and Cerebellum.
   It distributes its numerous Branches  chiefly  to the
Posterior Lobe of the  Bcain, one Branch in  particular 
                       228
penetrating into the posterior Coinu ofthe Lateral Vt-n.
tricle, and with Branches of the Internal Carotid, for-
ming the Arterious part of the Choroid Plexus.
  The Branches of this Artery  anastomose with those
ofthe anterior part of the Internal Carotid, at the in-
side ofthe Hemisphere,—an-l with those ofthe latent
part ofthe Artery, at the outside of the Hemisphere,
in the manner these  do with each other  in the other
parts of the Brain.
  The Arteria Communicans, which unites  the postelter
Cerebral Branch of the Vertebral Artery to the Tranjk
ofthe Internal Carotid, and is  nearly the  same diame-
ter, but longer than  that transverse Artery which con-
nects the anterior Branches ofthe Internal Carotid:
   It sends minute  Threads to the Crura  Cerebri, &c.
and contributes to-the formation of the Circle o/"Wil-
lis,—or  that kind  of Communication by which the
Blood or  Injected Matter can pass readily across from
one Internal Carotid to the other,—or from these back-
wards to the Basilar Artery.

    Veins ofthe Head and of Part ofthe Neck-

   The Veins which return the Blood from tlie Arteries
ofthe Head and Neck, unite into the following Trunks,
viz.
   The Facial Vein, which is formed by the  Frontal Vein,
and by an intricate Plexus of Branches upon the Face.  4
   It winds obliquely downwards and outwards, at a (tis-
tance from the Artery ; but in crossing the Jaw, it goes
close by the outside  of it, and terminates  in the Exter-
nal Jugular Vein.
   The Temporal Vein, formed  by superficial and deep
Branches from the sides and upper part  of the fLad}*'
and running  down upon the Temple at some distance
from the  Artery.
   The Branches of the Temporal Vein form large an-
astomoses,  before,  with  those of the Frontal Veins,
above, with their fellows on the other side  ; and behind,
 with the  Branches of the Occipital Vein.
   The Trunk descends at the fore-part ofthe ear, and,
along with the Artery,  is sunk in tlie substan-.-c cf'ix*
Parotid Gland. 
229
     In its descent  before the Meatus Auditorius Exter-
   nus, it receives Branches from the ear,  Parotid Gland,
   and Cheek,  corresponding  with the Arteries sent to
   tL^se parts from  the Carotid or Temporal Artery.
     At the under part of the  Lower Jaw, the Facial and
   Temporal Veins commonly unite and form the External
   Jugular.
     The External Jugular Vein  receives the following
   Branches at the upper part ofthe Neck, viz,
     Branches of the Internal Maxillary Vein,  the princi-
   pal part terminating in the Internal jugular.
     The Lingual Vein, one Branch of which, termed Pa*
   nina from its complexion, is  seen  under the Tongue,
   and is that Vein whicli is opened in the  Venesection of
   this Organ.
     Branches ofthe Occipital Vein, the rest passing to the
   Internal Jugular, and Vertebral Veins,  and  sometimes
   also communicating by a Foramen Mastoideum with the
   Lateral Sinus.
     The Trunk of the External Jugular Vein descends in
   the  Neck, between the  Paltysma Myoides and Sterno-
   xnastoid Muscles, receives in its course  Branches  from
1   the  adjacent parts, and terminates in tbe Subclavian
   Vein.
     In the formation and termination of this Vein, there
   is great variety in different Subjects.
     It  frequently happens that most of the Ramifications,
   which  commonly run from  the Face and Throat into
   this Vein, go to the internal Jugular.
     Often the Facial Vein goes into the Internal Jugular,
   and the Temporal continued forms the External Jugu-
   lar.
     Sometimes one ofthe external Jugulars terminates in
   the usual way, and the other in the Internal Jugular.
     In some rare cases, the external Jugulars have  both
   been found terminating in one side ofthe Neck.
     Anterior External Jugular Vein.  Besides the  Vein
   commonly called  External Jugular, a small Subcutane-
   ous Vein, termed Anterior External Jugular, descends
   in the fore-part of the Neck, receiving  Branches  fromn
   the adjacent parts, and terminating in  the Subclavian
   Vein.                                       .? 
280
         Veins of the Eye and its Appendages.

  The Blood sent to the Contents ofthe Orbit is return-
ed partly to the Facial Vein at the inner corner ofthe
Eye, but chiefly to the proper Ocular Vein, which ter-
minates in the Cavernous Sinus by  the following Veins,-
viz-
  The Vena Centralis Retin*, which is formed by many
small Branches expanded upon  the inner surface ofthe
Retina, along with those of the corresponding Artery.
  The Vena Centralis enters the  Optic  Nerve, where^j
the Artery leaves it; and a little behind the ball of the vf
Eye, it emerges from  the  Nerve,  and runs between H
and  the Sheath which covers it, receiving many Twigs   ^
from the Nerve and its Membranes.
  It passes afterwards under the Fasciculus of Nerves
which belongs to the Eye, and terminates, sometimes in   :
the Ocular Vein, but in general, directly in the  Caver-
nous Sinus.
  From the Iris and Choroid Coat, the Blood is return-
ed by  the  Short or Anterior  Ciliary  Veins,  and  by the
Long or Posterior Ciliary Veins, and also by a principal
set of Ciliary Veins, termed Vasa  Vorticosa.
  Small Veins return from the Iris, which go under the
Arterious  Circle to the Veins ofthe Choroid Coat, and
communicate with each other; but without forming any" 1
Circle, such as is found in tbe Eyes of Oxen, and which  J
corresponds, in them, with the Arterous Circle.        «
  The Anterior Ciliary Veins pass from the  Iris through i|
the Scleijotic coat, near the same part where the Anterior y
Ciliary Arteries enter.                               _
  The long Ciliary  Veins are commonly two in numben-^
like the Arteries, and of a smaller  size than the Vorti-
cose Veins.
  They run from the Iris backwards  along  the Choroid
coat, communicate in  their passage by minute Branches
with the Vorticose Veins, and afterwards perforate the
Tunica Sclerotica behind.
  The  ven* verticos*, are  numerous, and obtain  their
name from the whirls composed by their Branches, the
course of which has been compared to a Jet dfeau, or to
the  Spiral  Ridges upon the points ofthe ringers, 8cc
  Of these Veins, four, or sometimes five,  are by much 
231
 the most conspicuous, the rest being smaller, and having
 less of the Vorticose appearance.
   The Branches of each of the four principal Venx Vor-
 ticosac run in  close congeries, unite at acute angles into
 larger Branches which have a curved direction, and these
 proceeding from  a(l sides, meet in point, and form the
 Trunk of the Vein.
   The Trunks of these Venx Vorticosx, thus placed in
 the centre of their respective whirls are situated at the
. opposite sides of the  Eye, and perforate the Scierotic
 coat obliquely near its middle.
   The rest of the Venx Vorticosx,  or smaller Ciliary
 Veins, communicate with  the adjacent larger Vorticose
 Veins upon the surface ofthe Choroid coat, and also per-
 forates the Sclerotica near its middle.
    After piercing the Sclerotica, the different Vorticose
 Veins unite into four or five small Ciliary Trunks, receiv-
 ing a number  of minute Twigs, which paint  the Cellular
 Substance covering the Surface ofthe Sclerotica.
    The Ciliary Veins run in a serpentine direction at the
 opposite sides ofthe Eye, and  pass either separately or
 united with other small Veins in the Orbit, into the trunk
 ofthe Ocular Vein.
    The other Venous Branches within the Orbit Corres-
k pond in a great measure with their respective Arteries ;
 such as,
    Branches from  the  Palpebrx and inner corner of the
 Eye.
   The Lacrymal Branch :
   The OEthmaidal Branches :
    Muscular Branches,—and Branches from the Fat in the
 Orbit, and from the Membranes lining it.
   The different Branches from the Eye  and  its appenda-
 ges form, by their union, the Ocular vein, which greatly
 exceeds the size ofthe corresponding Artery.
    The Ocular Vein forms large Anastomoses, at the in-
 ner corner of  the  Eye, with  the Facial Vein, and after-
 wards passes back at the inner side ofthe Orbit.
    From the inner, it goes across to the outer side of the
 Orbit, under the  Attollens Muscle ; and after running
 back under the Anterior Clinoid Process, covered by the
 Third and Sixth Pair of Nerves, it terminates, under the
 Carotid  Artery, in the Cavernous Sinus. 
                        232
 Veins of the Dura Mater corresponding vith its Arteries.

  The veins ofthe Dura Mater accompany their Arteries'*
and  go partly  through Perforations in the Base ofthe  !
Cranium, to terminate in Branches ofthe External or In-  .
ternal Jugular Veins ;—the rest go into the nearest Simi-
ses of the Brain.

                  Veins of the Brain.

  The smaller Veins ofthe Brain accompany the ArteriesH
Their Trunks run chiefly between the Circumvolutions  J
ofthe  Brain, at a distance  from the Trunks  of the Ar-
teries,                                               j
  They terminate in the  different Sinuses of tbe Dun
Mate*-, and generally in an oblique direction, which pre-  j
vents the Blood from returning into them.            *
  The Sinuses  most commonly found are the  following,'
  The Superior Longitudinal Sinus, which  begins at the
under part of the Spine of tlie  Frontal Bone, runs along
the upper  edge of the Falx,—-and becoming gradually
wider, terminates upon the middle ofthe Occipital Bone,
in the two  Lateral Sinuses
  It receives the Blood from the upper part of the Brain
by several large Venous Trunks, which enter  it obliquely
forwards.
  The Torcular Herophili, or  Fourth  Sinus  of the An
cients, chiefly formed  by  the  Vena Galcni, which r
turns the Blood from the Choroid Plexus, Corpora Stri
ta,  Septum Lucidum, and  other  Internal parts of the
Brain.
  The Torcular passes back in the joining of the Falx
and Tentorium, and terminates along  with the Superior
Longitudinal Sinus, in the beginning of the Lateral Sinu-
ses.
  The Inferior  Longitudinal Sinus, a  remarkably small
one, situated in the under edge ofthe Falx.—It receives
Branches  from that  Membrane,  and  from the Corpus
Callosum and parts ofthe  Brain near it, and  terminates
in the beginning of Torcular Herophili.
  The two  Lateral Sinuses, or  Second and  Third Sinuses
ofthe Ancients, formed by the  Longitudinal and Torcu-
lar Sinus.
e"
An-J

riafl 
                         13J
   They run at the Posterior edge of the Tentorium, along
 the lateral ridges ofthe Os Occipitis, as far as the Base
 of the Petrosal  Processes of the Temporal Bones, from
 whence  they  wind downwards, pass through the Fora-
 mina Lacera  common to the  Occipital and  Temporal
 Bones, and Terminate in the  Internal Jugular Veins.
   Frequently one ofthe Lateral Sinuses is formed by the
 Longitudinal, and the other by the Torcular Sinus ; in
 which case, the one is found larger than the other.
   The Lateral Sinuses receive Veins from the Cerebel-
 lum and from the under and back-part of the Cerebrum ;
 they likewise receive the Blood from the following small
 Sinuses, situated under the Brain, viz.
   The Circular Sinus of Ridley, which is placed about
 the Glandula Pituitaria, and frequently surrounds it com-
 pletely, receiving the Blood from it and from the adjacent
 Bones and Membranes, and  terminating in the  Caver-
 nous Sinuses :
   •The Cavernous Sinuses, which are situated at the sides
 ofthe Sella Turcica, and receive Bloodfrom Veins lying
 near the lateral branches of tlie Internal Carotid Arteries
 from  the Ocular Veins, and from  the  Circular Sinus of
 Ridley :
   The Cavernosus Sinuses surround tbe Carotid Arteries
 and Sixth Pair of Nerves, and have a Cavernous Struc-
 ture within, somewhat resembling  that ofthe Penis :
   The Superior Petrosal Sinuses, situated upon the ridges
 ofthe Partes Petrosx.
  They receive some  small Veins from the Dura Mater
 and Base ofthe  Brain, aud communicate backwards with
 the Lateral, and forwards with the  Cavernous Sinuses.
  The Inferior Petrosal Sinuses, placed  at the roots of
the Partes  Petrosx.—They receive  the Blood from the
 Cavernous,  and discharge into tlie  ends  of the Lateral
 Sinuses.
  Besides the Sinuses mentioned  above, the  following
others are frequently met with, viz.
  A PerpeniUcular Occipital Sinus,  situated in the Falx
 Cerebelli, which is sometimes single,  sometimes double
and terminates in the Lateral Sinuses.—It receives Veins
 from the Dura Mater, and communicates with the Verte-
 bral Veins. -
   Anterior  Superior, and Anterior Inferior Occipital Sinu- 
234
ses, placed over the Cuneiform Process of tlie  Occipital
Bone, and communicating with the Inferior Petrosal and
Lateral Sinuses,  and with the Vertebral Veins.

                Internal Jugular Veins.

  The Lateral Sinuses, having received the Blood sent to
the Brain from the Carotid and Vertebral Arteries, pass
out ofthe Cranium, and form the Internal Jugular Veins;
each of which, at its origin is bulged back in form oft ''
Varix, which is termed Diverticulum; and this is lodged
in a Fossa at the root of the Pars Petrosa of the Tempo-
ral Bone.
   The Internal Jugular Vein descends behind the  Ster-
no-mastoid Muscle, upon tbe fore and outer part of the
common Carotid Artery, with which  it is  included in n
Sheath of Cellular Substance ; and  is frequently a good
deal dilated  towards its  under  Extremity,  especially  ,
in advanced life.                                     <
   In its course in the Neck, it receives
    Branches from  the Pharynx  and  Muscles  adjacent
to it:
   The Internal Maxillary vein .-
   One or more Branches from the Occiput:
   The Lingual vein, which sometimes terminates in the  ,
External Jugular :                                    j
   The Superior Laryngeal, and now and  then Inferior  j
 Laryngeal which more frequently goes  into the Subcla-
vian, or to the top of the Cava.
   The Internal Jugular also receives Branches from the
Muscles of the Neck, and at the length  terminates in the ]
Subclavian Vein.                                   *  1
The remaining Blood-Vessels of the  Neck, with those
       ofthe superior Extremity in General.
                    Arteries.
  Subclavian Artery.  The Subclavian Artery has been
already observed to arise on the  right  side, in common
with the Carotid; and on the left, to come off directly from
the Aorta. 
235
    After the Artery leaves  the Thorax, it passes trans-
  versely outwards at the under part ofthe  Neck, behind
  the under end of the Sterno-mastoid Muscle, and conti-
  nues its course outwards between the Anterior and middle}
  Scaleni Muscles, and between the Subclavian Muscle and
  first Rib.
    After crossing the first Rib, it goes under the Pectoral
  Muscles to the Axilla, where it obtains the name of Ax-
  illary Artery—In this course, it sends off the following
  branches, viz.
    The vertebral;—The Internal Mammary ;—The Su-
  perior Intercostal Artery-   The first of these has been
  already described ; tbe two others belong to the inner part
  ofthe Thorax.
    The Thyroidea, or Gutturalis Inferior, which arises at
  the outer side of the Vertebral, and, ascending obliquely
  inwards behind the Carotid Artery, gives Branches to
  the Trachea and Esophagus, and Muscles near them ;
  but is chiefly dispersed upon the  Thyroid  Gland, com-
  municating by  large  Anastomoses with the Laryngea
  Superior.
    The Cerviealis Antarior, which  frequently  comes off
  from the root of the Inferior Thyroid, and ascends in :
  the Neck, furnishing superficial Branches to the Mus- !
  cles which go from the Trunk ofthe Body to the Neck,
'  and deep Branches to the Glands, Nerves, &c. lying on !
  the fore  and lateral parts ofthe Cervical Vertebrx.
    The deep Branches anastomose with the  Vertebral
  and Occipital Arteries ;  and some passing through the
  Intervertebral Holes where the Nerves come out, com-
J. municate with the Spinal Arteries.
    The Cervicalis Posterior, which arises in common with
!' the Anterior Cervical, or with the Inferior Thyroid.—
  This  is larger than the former, lies farther out, and runs
  in a winding direction outwards and upwards.
    It supplies the  Skin and Muscles at the lateral and
  back-part of the  Neck, communicates with Branches of
  the Occipital and Vertebral Arteries, and  sends a prin-
  cipal Branch downwards to  the parts  about the top of
  the shoulder.
    The  Dersalis  Superior  Scapula, which comes fre-
:  quently from the root of the Thyroid, and running trans-
  versely behind the origin of the Su-rno-mastoid Muscle,
       VOL.  II.              o 
                        236
near the Clavicle,—perforates the Notch in the superior
Costa ofthe Scapula, and expanding its Branches upon
the Do>sum of  that  Bone, supplies the Spinati and o-
Iher Muscles  situated there, and  likewise furnishes
Branches to the  joint of the Shoulder.
  The Axillary Artery, lying in the Axilla, and surroun-
ded by the Lymphatic Glands and Fat, and by the large
Nerves which form the Brachial Plexus. The Axillary
Artery, give some small Branches to the parts adjacent;
but its principal Branches are,
  The Thoracic*, or  Mammair*  Externa,—three or
four in number,—which, by some Authors,  are descri-
bed by particular names ; as,
  The Ahoracica  Superior,  which gives Branches to
the Pectorales and Serratus, and some to the Intercos-
tal  Muscles:
  The Tharacica Lemga, which sends Twigs to the Ax-
illary Glands ; but goes  chiefly  to  the large Pectoni
Muscles,  Mamma, and  Integuments, and  inosculates
with the Branches ofthe Thoracica Superior.
  The Thoracica Humeralis, or Thoracic Artery of the
Shoulder, which goes off opposite the Thoracica Superior,
and divides suddenly into Branches which run to the up.
per parts of the Thorax near it, and to the Muscles and
Integuments surrounding the Articulation :
  Tlie Thoracica Axillaris,  which,  when  present, goes
off from or near to the Thoracica Humeralis, and is be-
stowed upon the Glands, Fat, 8tc. frequently dispeising
Branches  upon  the under  edge of the Subscapularis
Muscle.
  The Stapularis Interna, which soon divides  into the
Proper Scapularis Interna, and the Dorsalis  Scapula In-
ferior.
  The Scapularis  Interna runs near the inferior edge
of the Scapula, sends off many large Branches,  the
principal part of which are  dispersed upon the Latissi-
mus  Dorsi, Teres Major, and Subscapularis Muscles,
and have large Anastomoses with each other, and with
the Superior Dorsal Artery ofthe Scapula.
  'The Dorsalis  Scapul* Inferior, immediately after lea-
ving the Internal Scapulary Artery, turns round the in-
ner fdge of tlie  Scapula, a little below its Cervix.
  Upon the Posterior Surface of the Scapula, it spreads 
237
out into Branches of considerable size,  which are dis-
persed upon the  Muscles covering the under and back-
part of the Bone; while the Trunk, ascending, inoscu-
lates with that of the Superior  Dorsal Artery of the
Scapula, whereby an Arch common to the two Arteries
is formed at the root ofthe Acomion.
  The Circumflexa Anterior, or Articularis, which passes
in a transverse direction between the Heads ofthe Co-
racobrachial and Biceps Muscles, and Body ofthe Oa
Humeri, immediately  below the Joint ofthe Humerus.
  The Circumflexa, or Articularis Posterior, which arises
directly opposite to the former, and is by much the lar-
ger of the two.
  It passes first between the Subscapularis Muscle and
Teres Major, and then turns round between the back-
part of the Os Humeri, and long head  of the Triceps,
and the Deltoid Muscle, and  is dispersed  upon the
Deltoides and  parts  about the  Joint;—its extreme
Branches anastomosing with those ofthe Anterior Cir-
cumflex Artery, so as  completely to encompass the Bo-
dy  of the Bone.
  After giving offthese different Branches, the Axillary
Artery emerges from behind  the edge  of  the great
Pectoral Muscles, and runs along the Os Humeri, where
it is termed Humeral  or Brachial Artery.
  The Humeral Artery descends behi.id the inner edge
ofthe Biceps Muscle, covered by tbe Tendinous Apon-
eurosis of the Ann, and having the Triceps Extensor
Cubiti behind.   In this course, it bestows Branches  to
the Muscles and Integuments, and to  the Peritoneum
and Bone, viz.
  The Profunda Humeri,  or Spiralis, which arises near
the upper part of the Arm, at the insertion ofthe Latis-
aimus.Dorsi and Teres Major Muscles, taking a Spiral
direction downwards and outwards, between the Triceps
Muscle and Bone, and terminating at tlie outer Condyle
ofthe Os Humeri.
  The  Arteria  Profunda sends Branches  chiefly to the
Coraco brae hi alls and  Triceps Muscles, and to those at
the outer part ofthe Elbow ;—and one of them,-descen-
ding at the  inner side of the Arm, is sometimes so con-
siderable as to  form— 
238
   The Profunda Inferior, or Minor.  This  Artery is frc-
 quently a Branch of the  Profunda Superior, but more
 commonly an original Branch sent off from the Trunk
 ofthe Artery, near the middle ofthe Arm.
   It gives Branches  to the Muscles and other parts at
 the inside of the  Arm, and terminates about the inner
 part ofthe Os Humeri.
   The Ramus Anastomosticus Magnus, which comes off
 a little above the Elbow, and bestows Branches to the
 Brachialis Internus,  to the under end of the Triceps,
 and to the Parts in general about the  Elbow-Joint.
   Besides these, there are several other Branches sent
 in succession from the Trunk of the Humeral  Artery
 into  the Muscles and other parts adjacent.—These are
 shorter than the rest, and run more in a transverse di-
 xection, especially those to the Biceps  Muscle.—One
 small Branch, termed Nutritia,  or Medullaris, pene-
 trates the substance of the Bone  by the  passage near
 its middle, and supplies  the  Marrow and parts which
 contain it.
   The Trunk ofthe Humeral Artery having sent off the
 different Branches which belong to the Arm, passes to
 the  middle of the bending of the  Elbow, between the
 Aponeurosis  and round Tendon ofthe Biceps Muscle. ,
   About an inch below the Elbow, it commonly divides
 into  two principal  Arteries, the Radial and Ulnar. It
 happens,  however, now  and then,  that this Division
 takes place about the middle  ofthe Arm ; and in cer-
 tain  instances, as high as the Axilla.
   The Radialis passes over the Pronator Teres Muscle,
 and follows the course ofthe Radius through the whole
 length of that Bone.
   At the upper part ofthe Fore-Arm,  it  is covered by
 the Supinator Longus : In its  descent, it becomes more
 superficial, and, at the under part  of the  Fore-Arm, it
lies close upon the Radius, and immediately under the
 Skin, in "consequence of which, the Pulse  is commonly
felt in this place.
   The Recurrens  Radialis, which  is reflected  to the
Muscles and Parts ofthe  Joint near it, and anastomoses
freely with the Arteria Profunda Humeri  at the outer
 part  of the Elbow.
   Numerous  Lateral Branches, in  the descent of the
 
                       239
Artery, to the Mnscles and Integuments, and parts in
general situated about the Radius.
  A Branch at the Wrist, which goes over the Root of
the Thumb, and  sometimes a  principal  Branch along
one side of it;—at other times, it is dispersed upon the
Palm ofthe Hand.
  Small Branches to the Ligaments, Bones and other
parts about the Wrist.
  One, or sometimes two Branches, termed  Dorsal, to
the back-part ofthe Metacarpos and Fingers.
  At the under end ofthe Fore-Arm, the Radial  Artery
turns back under the Tendons of the Extensors ofthe
Thumb,  and gets between the  Roots ofthe Metacarpal
Bones of the Thumb and Fore-Finger, where it divides
into three principal Branches,  viz.
  The*yf. Magna Pallia's,  which runs along the  side of
the Thumb next the Fingers, and sometimes divides at
its  root, into two Branches, whicli supply both sides
of it.
  The Radialis Indicis, which runs along the side ofthe
Fore-fingers next the Thumb.
  The Palmaris  Profunda, which crosses  the Hand be-
tween the roots ofthe Metacarpal Bones and Flexures
of  the  Fingers, and forms an  Arcus Profundus, from
which Branches go off to the Interossei Muscles and
other deep parts of the Palm.
  The Ulnaris appears at first as the continuation of the
Trunk ofthe Humeral Artery.
  At its upper part,  it  sinks deep  behind the  Flexor
Muscles of the  Hand, and passes afterwards for some
way between the Flexor Sublimis and Profundus Digi-
torum.
  Near  the Wrist, it becomes more superficial, and runs
between the  Tendons of the Flexor Carpi Ulnaris and
Flexor Digitorum Profundus,  to the Hand.
   In this course, it sends off many Branches to the Fore-
arm, among which the  following are the most conside-
rable.
  The Recurrens Ulnaris, which runs deep among the
Flexor Muscles, and soon divides into Branches which
ascend and supply  the parts about the under and inner
side of the Elbow.—In the Groove behind the inner
Condyle ofthe Os  Humeri, itcommurricVes by distinct
                        o  2 
                       240
Anastomoses  with  the Profunda Inferior, or with th*
Ramus Anastomoticus, sent down  from the Humeral
Artery.
  The Intcrossea Posterior, which comes off atthe up.
per end of the  Interosseous Ligament, perforating it
immediately at its origin, and going to the back part of
the Fore-arm.
  From this place, it-sends upwards a Recurrent Branch
which communicates, upon the back-part ofthe Elbow,
with the other Recurrent Arteries, and with the Bran.
dies sent down from  the Humeral Artery, and forms
along with  these a Plexus  of Vessels  upon the back-
part of the Joint.
  The Interossea is  afterwards continued downwards,
and is chiefly dispersed upon the  Bellies  of the Exter-
nal Muscles ofthe Hand and Fingers, being commonly
exhausted before it reaches the Wrist.
  The Internossea  Anterior, which comes  off sometimes
immediately  below the former, and at other times in
common with it.  It is considerably tbe larger of tbe
two ;  but only about half the size of tbe Ulnar Artery
from  which it springs.
  It runs close  upon the Interosseous Ligament, and
furnishes Branches to the Muscles and deep parts upon
the anterior side of the Fore-arm.
  Near the Wrist, it perforates the Ligament, and goes
to the Posterior side of the Carpus and back ofthe
Hand, dividing into Branches  which inosculate with o-
thers ofthe Posterior Interosseous and Radial Arteries.
  The  Ulnar Artery, having given off  its recurrent
Branch, and the Arterixlnterossex, with  many Lateral
Branches to the inner side of the Fore-arm, passes by *
the side of the Os Pisiforme, and then over the Annular °*
Ligament into the  Palm, where it forms the Arcus vola-
ris superficialis.
  At the under end of the Fore-arm, it sends off a Dorsal
Branch, which passes under the Tendon  of the Flexor
Carpi Ulnaris to the back of the Hand, where joining
with the Branches ofthe Anterior Interosseous and Ul-
nar Arteries, it assists in forming a Plexus which sup-
plies  the back-part of the Wrist and of the Hand and
Fingers with a  number of Branches,  which are  small
when compared with those in the Palm- 
241
  The Arcus Volaris  Sublimis, or Superficialis, is pla-
ced with its convex side downwards,  and extends ob-
liquely from the root of the Metacarpal Bone of the lit-
tle Finger towards that ofthe first Bone ofthe Thumb,
being covered by the expansion termed Aponeurosis Pal-
mar is.
  From the Arcus  Volaris, Branches are sent off in the
following order, viz.
  Several  small Branches to  the Integuments and o-
ther superficial parts ofthe Palm :
  A considerable Branch  which sinks near the root of
the Metacarpal Bone ofthe little Finger, and inosculat-
ing with the Palmar Branch of the Radial Artery, as-
sists in forming the Arcus Profundus :
   A Branch to the inner side ofthe little Finger :
   Three large Digital Branches which run opposite tothe
Interstices of the Metacarpal Bones, to the roots of or
Clefts between the Fingers.
   At these Clefts, each ofthe three Digital Arteries is
 divided into two Branches,  one of which Branches of
 each division runs along the Anterior Radial margin of
 one Finger, and the other along the Anterior Ulnar mar-
 gin ofthe  Finger next it;—the three  Digital Arteries
 thus supplying the margins of all the Fingers, excepting
 the inner margin ofthe little Finger, and the outer mar-
 gin of the  Index.
   At the roots of the  Fingers, each of the Digital Ar-
 teries receives a small Branch from the Arcus Profun-
 dus.
   At the rocts and Joints, but more particularly at the
 Points of  the  Fingers, the Arteries  communicate  by
 cross Arches, and send Branches to the parts adjacent.
 .  The Superficial Arch of the Palm commonly sends off
 one ofthe  Arteries of the Thumb, and ultimately com-
 municates by a large Anastomoses with the root of tlie
 Arteria Magna Pollicis.


 VEINS OF THE SUPERIOR EXTREMITY AND
            OF PART OF THE  NECK.

   The Veins of the  Superior Extremities have nume-
 rous Valves, and are divided into a  Superficial and a
                        O 3 
                       242                          '
Deep Set; the former lying immediately under the In»   ,
teguments, the latter  accompanying  the Arteries, and
taking their name from them.                          j
  The Subcutaneous Veins have many large Anastomo-   i|
sea with each other, particularly on the Fore-arm, where
they unite, separate, and re-unite several  times, thus   !|
forming a Plexus by which it is surrounded.            |
  The Superficial Veins from the back of the Hand (on*   \}
of which, belonging to the  little  Finger, was termed   •
Salvatella by the Ancients) go chiefly to the Superficial
Radial,  and partly also to the Ulnar veins.
  The Superficial Radial Veins form the vena Cephalita,
and the  Superficial Ulnar Veins the vena Basilica, at the
Joint of the Elbow.
  The  Superficial Veins  on the Anterior  part of the   j
Fore-arm communicate laterally with  the  Radial and   i
Ulnar Veins, and, in their ascent, form a Trunk termed   fl
Mediana Longa.
  Tlie Mediana Longa, a little below the bending ofthe   I
Elbow,  is divided into Mediana Cephulica and Mediana
Basilica, which running obliquely  upwards, terminate   1
a little above the Elbow, the former in the  Cephalic,   I
and the latter,  crossing  over  the  Humeral Artery, io   *
the Basilic Vein.
  Though this description corresponds with the general
distribution ofthe Veins ofthe Fore-arm ; yet, so great
is the variety among them, that they are scarcely found
to agree exactly in any two Subjects.
  The Basilica, in its ascent, forms tbe principal Hume-    i
ral Vein, which passes along the side ofthe Os Hume-   y
ri, a little to the inside ofthe Humeral Artery, and re-
ceiving Branches from  the corresponding side of the
Arm, it runs into the Arm-pit, and forms the  Vena Ax-
illaris.                                                ;.
  The Cephalica ascends  at the outside of the Bicepa   '
Muscle, receives Branches from the adjacent parts of
the Arm, and communicates in several places with the
Basilic, and  passing in the  Groove  between  the large
Pectoral and the  Deltoid Muscle,  terminates in  the
Axillary Vein.
  The Deep veins, termed also venx Satellites, or Conco-
mites run close by the side of their respective Arteries,
one lying commonly on each side of the Artery, and re-
ceiving the Blood from the adjacent  parts. 
243
  In various places they anastomose with each other by
short Branches, which cross over the Arteries.
  Near the joint of the Elbow, the Deep Radial Ulnar,
and  Interosseous  Veins, form a Plexus over the Bifurca-
tion of the Humeral Artery.
  From this Plexus, a short but large Branch passes out-
wards, and forms a Communication with one ofthe Sub-
cutaneous Veins, and, in general, the Communications is
with one of the Median Veins.
  The Vena Axillaris, formed by the Trunks of the Su-
perficial and Deep Humeral Veins, receives the Veins
corresponding  with the  Circumflex  Arteries,  and the
Internal,  and the Inferior  Dorsal Veins of the Scapula.
  A little higher, it is  jointed by the  Ven*  Thoracic*
Extern* and about this place, changes its names for that
of Subclavian  Vein.
  The Vena Subclavia passes between the Clavicle and
first Kib, at the inner side of the trunk of  the Artery,
and  afterwards goes  over the fore-part of the Anterior
Scalenus Muscle, at the under end of the Neck.
   After crossing the first Rib, it receives the  Vein cor-
responding with the Superior  Dorsal Artery of_the Sca-
pula  others whirh  belong to tbe Cervical Arteries, and
also small veins from the Skin and  Muscles  on the back-
part of the Neck-
   While situated in the Neck, it likewise  receives the
External, and then the Internal Jugular Veins ; and near
this last a Vein of considerable size, which corresponds
with the Trunk of the  Vertebral  Artery.
   The Vertebral Vein  communicates within the Cranium,
by small branches, with the Inferior Petrosal Sinuses, or
with  Occipital  Sinuses; but is chiefly formed by branches
arising from  tbe Spinal  Marrow and its  Membranes,
and  from the  Bones and  deep-seated Muscles of the
Neck.
   Behind the  top of the  Sternum, the Subclavian Vein
frequently receives the Inferior  Laryngeal  Vein, the An-
terior External Jugular,  and the Internal Mammary
ftin.—Besides these, the  Left  Subclavian  receives alsd
Ihe  Left Superior Intercostal Vein ;  after which, it goes
across the Root of the Great Arteries sent up from the
Arch of the  Aorta, and joins its fellow on the opposite
stdv to form the Superior Cava.
                         O  4 
                        244
    BLOOD-VESSELS WITHIN THE THORAX.
    Of the Blood-Vessels within the Thorax, the Pulmo-
  nary Artery and veins, the Aorta,  the Coronary Vessels,
  and the other Vessels connected with the Heart have
  been already noticed.
    The following are those  which remain to be described.
    The Mammaria Interna, which arises from  the Sub-
  clavian, opposite to the Inferior Laryngeal, and  descends
  between the Pleura and Cartilages of the True Ribs, at
  the edge of the  Sternum ;—sending off,
    A Small Reflected Branch to the Integuments  and
  Muscles adjacent to the Clavicle :
    One or two small Branches,  termed Thymic*, to the
  Thymus Gland, and  which, like  the Gland itself, are
  most considerable in the Young Subject:
    A minute  Branch,  termed  Comes  Nervi  Phrenict^
  which Accompanies the Phrenic Nerve, and after giving.
  Twigs to the neighbouring Membranes,  is distributed
  upon the Diaphragm :
    Some small Branches, called Mediastina, Pericardia,
  to the Mediastinum and Pericardium :
    Several Branches  outwards,  to  the Intercostal Mus-
  cles ;  and others between the Cartilages  of the True
  Ribs at the edge of the Sternum,  to the Pectoral Mus-
  cles, Mamma and  Integuments,  which  communicate
  with those of the Thoracica: Extcrnx :
    A Large Branch,  at the under end  of  the  Thorax,
  which is dispersed upon the Diaphragm.
   The Mammary Artery afterwards emerges  from the
 Thorax, commonly under  the Cartilage of the Seventh
 True Rib, and runs upon  the  back-part of the Rectus
 Abdominis Muscle, upon  the upper end of which it is
 dispersed, after sending a Branch to the Oblique Muscles
 of the Abdomen.
   1 he  Intercostalis  Superior,  which comes off a little
 farther out than the  Mammary, and descending near
 the Spine, commonly divides into two or three Branches,
 which supply an equal number of Intercostal Spares  It
 also sends  a Branch upwards to the Deep Musics • t
 the under and fore-part of the Neck.
   The Arteri* Bronchioles,  one in the right and two or
tlrree m the left side ofthe Thorax, which are dispersed
upon tlie corresponding sides of the Lungs. 
245
   The Bronchialis Dextra, which arises most frequently
 from the uppermost Intercostal  Artery of the Aorta;
 and the Bronchioles Sinistra, which are of unequal size,
 from the forepart of the  Aorta at a little distance from
 each other.
   The Bronchial Arteries send small  Branches to the
 Esophagus,  to the Posterior Mediastinum and Pericar-
 dium, and afterwards accompany those of the Trachea
 through the Substance ofthe Lungs.
   The Arteria Esophage*, which are minute Branches
 arising from the Aorta, and dispersed upon the Eso-
 phagus,  also sending Twigs to the Posterior Mediasti-
 num.
   The Intercostales inferiores,  which are nine or  ten
 pairs in number, arising from the back-part ofthe Aorta,
 and running in the Grooves at  the under edges  ofthe
 Ribs, between the External and Internal Intercostal Mus-
 cles.
   They furnish Branches to the Spine and  Spinal Mar-
 row, to the  Intercostal Muscles, Pleura, &c. also nume-
 rous Branches to the Muscles in the back ofthe Thorax,
 and communicate with those of the Internal and Exter-
 nal Mammary Arteries.
                       Veins-
   The Blood sent to the Thorax by the Arterix Mamma-
 rix Interna:, Intercostales, and Esophagex,  is returned
 to the Heart by the following Veins, viz.
   The Mammaria Interna, which accompany their cor-
 responding Arteries, and terminate, the Left in the Sub-
 clavian,  and the right in this, or in the top of the  Vena
 Cava.
   Some small Veins, as  the Pericardiaco-Diaphragmat-
ic, the Thymic and Pericardiac,  which,  in place of join-
 ing the Mammary Trunk, commonly terminate, the Right
 in the Subclavian or top of the Cava, and the Left in the
 corresponding Subclavian Vein.
  The ven*  Intercostales, which are the same in  num-
ber with  their Arteries, and accompany them along the
 edges of  the Ribs.
  Several of the Lower left  Intercostals unite into a
trunk, termed vena Azygos, which crosses over the  Spine
 about the middle of the Thorax,—behind, but sometimes
before the Trunk ofthe Aorta,—to the right side. 
246
  The vena  Azygos,  or vena fine  Pari, thus originally
formed by the Lower Left Intercostals, ascends on the
fore  part of the Spine over the Intercostals,  Arteries,  !
at the right side of the Aorta.
  At its lower extremity, it generally communicates with  ,
one ofthe Lumbar Veins,  or with the Vena Renalis; and
not unfrequenlly with the Trunk of the Inferior Cava.
  Upon the Spine, it receive the Right Intercostals, and
the  Right  Bronchial  veins and tuiming forwards over  <
the  Root of the Great Pulmonary  Vessels of that side,
it terminates in the Superior Cava.
   The Upper Left Intercostal  veins, or such as are not
received by the Vena Azygos, terminate in a trunk on  •
the left side, improperly called Left Vena Azygos.
  The Left  vena Azygos, Left Bronchial,  or Left Su-
perior Intercostal vein, besides the Superior Intercostal
Branches,  receives  the  Left Bronchial  Veins  and
Branches,  from the Esophagus and other parts  near it,
and terminates in the Subclavian Vein.
   The vena Cava Superior,—formed by the  union of the
Subclavian Veins, with the addition of the Vena Azygos,
—passes down at the right side of the ascending Aorta,
perforates the Pericardium, and terminates  in the upper
part of the Right  Auricle.

             Blood-vessels ofthe Diaphragm-

   The Diaphragm is supplied with Blood-vessels from
various sources, viz. those entering its upper-part from
the  Internal Mammary,  already described; also small
Branches from the Intercostal and Lumbar Arteries. Its
principal Branches,  however,  are tlie Phrenic,  or  Dia-
phragmatic.
 ^ The Arteria Diaphragmatic*, are two in  number, one
 on each side, which arise from the fore-part  ofthe Aorta
as soon as it enters the Abdomen.
   In general,  their  origin is distinct  from  each other,
but  sometimes by a common Trunk ; and now and then,
one or both, originate from the root of the Coeliaca.
   Tbey afterwards go obliquely upwards and outwards
over the Crura of the Diaphragm, spread out into many
Branches  which  are chiefly dispersed upon its Fleshy
sides, nnd inosculate with those Which enter at is up-
per  surface. 
247
  They likewise  give small Branches to the Glandulx
Renales, to the Cardia,  and parts in general  which lie
near them.
  The  ven* Diaphragmatic*,  like their corresponding
Arteries, run upon the under part of the Diaphragm, and
terminate in the  Inferior Cava, behind the  Liver,—the
right being commonly at a little lower than the left.
  BLOOD-VESSELS of the CHYLOPOETIC, and
     ASSISTANT CHYLOPOETIC VISCERA.
                     ARTERIES.
  The Arteries of these Vicera, consist of the Cccliac,
and the Superior and Inferior Mesenteries ; all of which
are  Azygus  or single Arteries arising from  tlie  fore
part of the Aoita.

                  Arteria Caliaca.
  The Arteria Caliaca, arises from the Aorta,  immedi-
ately after  it emerges from between the Crura of the
Diaphragm into the abdomen;  and is situated at the up-
per edge of the Pancreas,
  The Trunk of the Cccliae Artery is remarkably short,
being ltllLe jnore  tlun half an  inch in length,  before it
divides into its three jirincipal Branches,  called from
their destination,  Superior Gastric, Hepatic, and Sple.
nic.
  The G-astrica Superior, or Coronaria ventriculi Superi-
or, is tbe smallest of the three.  It goes upwards, and
a little towards the left, to reach  the  right side of the
upper Orifice of the Stomach.
  Here it sends Branches to the Cardia, which encircle
it, and ascending  someway  upon  the  Esophagus, com-
municate with the Arterix Esophagex.
  The Trunk of the Artery afterwards divides  upon the
small Curvature ofthe Stomach, into principal Branches,
some of which run across the upper and under  Surfaces,
and others obliquely  towards the right side.; supplying
a large portion of the Stomach, and sending Twigs to
the Omentum Minus,—while the trunk U frequently ex-
tended as far as the Pylorus. 
248
A
  The Arteria Hcpatica, the largest of the three, pas-,;
ses obliquely upwards, towards the Pylorus,—before.
and a little to the right side ofthe Lobulons Spigelii,—
till it  arrives at the Cavity of the Liver called PortOi
  Where it approaches the  Porta, it  divides into the
Gastrica-Inferior Dextra, and the  Proper Hepatic Ar-
tery.
  The Gastrica Dextra, or Gastrica Inferior Dextra, or
Gastro-Epiploic a Dextra, sends out—
  The Arteria Pylorica, which, however, is  frequently
produced immediately  from the  Hepatic  Artery.  It
gives Branches to the Pylorus and other parts about
the small  end of the "Stomach,  and afterwards runs_
some way along its small Curvature,  inosculating with,
the Superior Gastric Artery.
   Besides this principal Branch, there are a few smal
ler ones sent from the Gastrica Inferior to the Pylorus.
   Tbe Duodenalis,  which is dispersed upon  the  begii
ning and right  portion of the  Duodenum,  along wi
other Branches  coming  from the same source,  but of
inferior size.
   Rami Pancreatici, distributed to the right end of the
Pancreas.
   After furnishing the Branches already mentioned, the
Inferior Gastric Artery passes under the Pylorus to the
gTeat Curvature of the Stomach,  along which it runs;
being included, to near its large extremity,  in the Lay-
ers of the Anterior Portion of tlie Omentum.
   In this course, it sends off—
   The  Rami Epiploici, which are  long  and slendei
Branches  dispersed  upon the Epiploon or  Omentum.
   The  Rami Gastrici, whicli  plunging suddenly  into»--<
both sides of the Stomach, communicate with the Py-
loric and superior Gastric Arteries.
   The Hepatic Artery, hating given out the Inferior
 Gastric, and frequently, the Ploric Artery, soon divides
into two principal Branches, a right and left, of unequal J
 size, which run into the Porta;—the one,—under the >
 Hepatic Duct,—to supply the great, and the other the
 small Lobe of the Liver.
   From the Right Branch, before it plunges  into tlie
 Liver, is sent off the Arteria Cystica afterwards divid-
A 
                          249
 ing into two smaller Branches, termed Gemell*. which
 are dispersed upon the Gall-bladder.
   Frequently, besides  the  Hepatic  Artery,  sent  oft
 from the Cccliac, there is another coming sometimes
 from the Superior Gastric, at other times from the Su-
 perior  Mesenteric Artery,  to be  sent into the Liver.
 In such cases, the Trunk which gives origin to this ad-
 ditional Artery  is greater than usual, and the Hepa-
 tic Branch which it accompanies is proportionally smal-

 *er"                                    ►
   The  Arteria Splenica,  nearly  equal in size to the
 Trunk  of the Hepatica,  takes  a  long and serpentine
 course  across the left  side of the  Body ; running first
 behind, then at the upper part of the Pancreas in its
 way to the Spleen.  Its Branches are,----
•   The  Rami Pancreatici, which are few in ni mber and
 small.   They run from the Splenic Artery nearly at
 right angles, and supply the greater part of the  Pan-
 creas.
   The Gastrica  Sinistra,  Gastrica  Inferior Sinistra, or
 Gastro-Epiploica Sinistra, which is considerably inferior
 in length and size to the Gastrica Dextra.  It commu-
 nicates by its Branches with the Gastrica Superior, and
 Inferior, while its Trunk runs a  little way towards the
 right side along  the  great Curvature of the Stomach.
   It sends some Rami  Pancreatici, and Gastro-Epiploi-
 ci, and Meso colici Sinistri, to the Pancreas,  left por-
 tions ofthe Omentum and Mesocolon ; while its Trunk
 frequently  forms a common Arch with the  Gastrica
 Dextra.
"   Three or four considerable Branches, termed  vasa
 Brevia, or Arteri* Breves, which run to the left part of
 the great Curvature of the Stomach, to be distributed
 upon its large extremity ; their Ramifications anasto-
 mosing with those of the  Superior and of the  Left  In.
 fcrior Gastric Arteries.
   The  Rami Splenici, several in number and of conside-
 rable size, which go  at the concave side of the Spleen,
 to be distributed throughout the whole of its substance.

                  Mescnterica Superior.

   The  Mesenterica Superior  arises  from the Aorta, im-
 mediately below the Cccliac Artery, which it equals in 
                       250
size ; and running under the Pancreas, and then over
the Duodenum, it passes between the  Layers of the
Mesentery towards the under side of the Abdomen.    ]
  In its descent, it is bent  a Tittle to the left side, its  J;
lower extremity turning towards the beginning of the  1'
Colon.                                             "
  From the  convex side of the  Artery,  many large  j
Branches  are sent off to the small Intestines ; while o-  *
thers proceed in the opposite direction to the right side  )
ofthe Colon.
  The First Arteries sent off from the Trunk are very  j
inconsiderable, running to the Pancreas and to the left  '
portion of the  Duodenum,  and communicating there
with Branches ofthe Cceliac Artery.
  Tbe principal  Branches from  the  left side of  the  j
Trunk are dispersed upon the Jejunum and Ilium, sup.  i
plying, in tlieir course, the  Layers of the Mesentery  '
with the parts it contains.
  The first of these Branches are short and small, those
which succeed gradually increase in length and size to '
the middle of the  Arch, after which they diminish a-
gain somewhat in the same proportion towards the low-
er part of the Ilium
  In their course through the Mesentery, the principal
Branches communicate, first by reciprocal Arches, then ..
by Areolx of different figures, which increase in num.
ber, but diminish in size as they  approach  the Intes-
tines.                                             |
   From these Areolx, many  Branches are detached, J
which take a straight  course to the' Intestines,  and are '
afterwards ramified through  their substance, forming "
numberless Anastomoses with each other.
  Tlie Branches produced  from the  right or concave
s^de of the Trunk are  situated  between the Layers of
the Meso-colon,—their length being almost equal to the
breadth of that Membrane.
   Near the Intestines, they communicate by large and
then by smaller Arcbes : These last,  however, are less
frequent than those which belong to  the small Intes-
tines.
   The principal Branches are the following :—
   The Ileo-colica, which arises near tlie  under part of
the  Trunk, supplies the end ofthe Ilium and beginning 
20 1
ofthe Colon, and communicates with the Branches sent
from the extremity ofthe Trunk ofthe Artery.
  A Short Trunk, which divides into—
  The Colica Dextra, for supplying the right side ofthe
Colen, its Branches communicating with those of the
Heo-Colica :  And
  The Colica-Mcdia, or Media Anastomotica, which pro-
ceeds to the  great Arch of the Colon.
  Near the Colon, the Colica Media divides into two
large Branches ; one forming an  Archtwith the Dextra,
the other with a Branch of the Mesenterica Inferior.
  From the opposite side of the Colon Branches of this
Artery run to the Omentum, and communicate with the
Gastro-Epiploic Arteries.
  Besides the Colic Branches already described, there
is frequently an additional  one, which arises from the
beginning of the Superior Mensenteric  Artery, and in
its  ascent splits into two others,  one  of which, uniting
with the Colica Media, forms the large Mosocolic Arch
and the other a similar Arch with the ascending Branch
of  the Inferior Mesenteric Artery.

                Mesenterica Inferior.

  The Mesenterica Inferior arises from the Aorta some-
what lower than half way between the Superior Mensen-
teric and the Bifurcation of the Aorta.
   It descends obliquely upon the left Psoas Muscle, and
 soon divides into principal Branches.
   These near the Intestines join each other, and form
 Arches, from which others go off composing  Areolx in
 some measure  similar to those which belong to  the
 right side ofthe Colon.—-The principal Branches are :—
   The Ramus Ascendens, which divides near the Intes-
 tine, into two Branches;  one of which joins the Colica
 Media,  to form the great Mesocolic Arch, the other is
 reflected upon the  left portion ofthe Colon.
   The Colica Sinistra, whicli is frequently double  from
 its origin, or at other times splitting into two Branches,
 one joining  the Ramus Ascendens, the  other passing
 down by the Sigmoid Flexure ofthe Colon.
   The Hemorrhoidalis Interna, which is the Trunk con.
 vinued.   It anastomoses  with the Colica Sinistra, and- 
252
 afterwards descends upon the back-part of the Rectum
 to near its under extremity.

                        Veins-                  w    i

  The Veins which return the Blood from the Chylopo- j
 etic and assistant Chylopoetic Viscera, accompany their |
 respective Arteries,—the  Hepatic Branches excepted, "f
 They have, like their Arteries, large and frequent com- '
 munications with each other, are much superior in size,
 and, as well as the other Veins  of  the  Viscera situated*
 in the great Cavities, are  destitute of Valves.         J

        The following are the principal Trunks.

  The Mesenterica, or Mesaraica Minor, or H*morrhoi-
 dalis Interna-
  The Mesenterica Minor, running up at the left side of
 the Spine, receives—
  The Proper vena Hxmorrhoidalis Interna, which re-
 turns the Blood from the  Intestinum Rectum ;— the
 name obtained from  the Vein being supposed to be con- j
 nected with the  Tumours called Hamorrhoids or Pilis.
  The vena Colic* Sinistra, which return the Bloodfrom
 the left portion or side of the Colon.
  A vena Duodenalis, Which returns the Bloodfrom the ,
 left portion ofthe Duodenum.
  The Mesenterica Minor commonly terminates in the
 Vena Splenica, though not unfrequently in the Mesen-  ,
 terica Superior.
   Vena Splenica.—The Vena  Splenica, situated at the*?
 under  side of its Artery  and  immediately behind the
 Pancreas, receives—
  The Rami Splenici, which return the Blood from the
 Spleen:
  The Rami Pancreatici, which pass from the under end
ofthe Pancreas -•
  The Vena Breves,  or Vasa Brevia, which come from
tbe left or great  end ofthe Stomach.
  The Vena Gastrica Sinistra, or Epiploica Sinistra,
which comes from  part of the great Arch of the Sto-
mach,  and corresponding portion ofthe Omentum :
  The Gastrica Superior, which come  from  the  small j 
253
 Curvature of the Stomach and Omentum Minus, and
 goes into the  Splenic  near  its termination, or into the
 beginning of the Vena Portx-
   The Splenic and Inferior Mesenteric Veins, after re-
 ceiving their respective Branches, form a short Trunk
 which joins the Superior Mesenteric.
   Vena Mesenterica  Superior, or Major.  The Great
 Mesenteric Vein, situated at the under side of the Ar-
 tery, receives—
   The Rami Mesenterici, which are very large and nur
 merous, returning the Blood from the Jejunum and Ili-
 um,—the Branches going into the left side of the gen-
 eral Trunk,
   The Ileo-Colica, which comes from the end  of the
 Ilium and beginning ofthe Colon.
   The Colica Dextra, which belongs to the right  side of
 the Colon, and terminates in the right or concave side,
 of the Mesenteric Trunk.
   The Colica Media Anastomotica,  which comes from
 the right portion ofthe Great Arch ofthe Colon, form-
 ing, with the descending Branch of the Mesenterica
 Minor,  a large  Arch similar to that of the correspond-
 ing Artery, and terminating also in the right side ofthe
 Trunk.
   The  Gastro Epiploica  Dextra, which belongs to the
 right portions ofthe Stomach  and Omentum, and fre-
 quently unUes with the Veins from the side ofthe Colon,
 forming a short common Trunk, which has the term of
 Gastro-Colica applied to it.
   The Pylorica and Duodenalis, which sometimes ter-
 minate in the  Superior Mesenteric, at other  times  in
 the Gastrica Dextra.
   The Great Mesenteric Vein, formed by the  Branches
 mentioned above, passes over the beginning of the cor-
 responding Artery, and joins the Vena Splenica.
   The Trunk formed by these Veins, run under the
 bead of the  Pancreas, and here obtains  the name of
 Vena Port*, or V- Port arum.

                     Vena Port*.

   The Vena Port*, formed by the two  Mesenteries, and
H>y the Splenic  Vein, returns the blood from the Sto-
Y   VOL. II.             P 
254
mach and Intestine, and from the Spleen, Pancreas, ami ,
Omenta.
  The under part of the Vena Portx is termed by some
Authors Vena Portx Abdominalis, or Ventralis; while
the upper part,—being of great size, but without haying
any particular Dilatation in it,—is  called Sinus ofthe
Vena Portx.
  The Vena Portx, at its beginning, frequently receives
the Vena Gastrica Dextra, the Gastrica Superior, the
Pylorica, and the Duodenalis, which at other times ter-
minate  in one of the great Trunks which form it.
  It passes upwards, inclining a little to the right in its
course to the Liver, having  the Trunks of the Biliary
Ducts before, and the Hepatic Artery on the left side 1
of it,—and is about three or four inches in length.
  When it reaches the Porta of the Liver, it receives
the Venx Cysticx into its Trunk, or into its right divi-
Bion, either  by two separate Branches, or these united
into a single Vein.
   In the Porta,  it  divides into two great Branches, a
right and a  left, sometimes termed Venx Portx Heps-
ticx, which  go off nearly at right angles, to be dispers-
ed through the substance of the Liver, after the man-
ner of an Artery, the  subordinate Branches accompany-
ing those ofthe A. Hepatica.
   From the extremities  of the Vena Portarum, and .
likewise from the extremities ofthe Hepatic Artery, a
set of Veins  arise, termed Venx Hepaticx, and Some- j
times  Venx  Cavx Hepaticx, which accompany the -f
Branches ofthe Hepatic Artery and Vena Portarum. —
   The  Branches of the Venx Hepaticx afterwards unite
 into large Trunks, which  recede from the Hepatic Ar-
tery and Vena Portx, and  terminate in the  Inferkl*
 Cava.
   Their termination in  the Cava is by two,' and fre-
quently by three Trunks, at the place where it perfor-
 ates the Diaphragm : but commonly, below this, a few
 small  Hepatic Branches go into  the  Cava where it is
situated behind the Liver.
 
255
 BLOOD-VESSELS of the ORGANS of

        URINE and GENERATION.

  Arteria Renalis. The Arteria Renalis, called also A.
 Emulgens, arise from the side ofthe Aorta, a little be-
 low the root of the Superior Mesenterica Artery.
  It commonly comes off by one large Trunk, though
 frequently by two or more, in which case, each of these
 is smaller than when the Artery is single.
  It runs across the Spine and Psoas Muscle, nearly in
 a transverse direction.   The  Artery of the right Bide
 goes behind the Vena Cava, and is longer than the left
 in consequence ofthe Cava being situated between the
 Aorta and the right Kidney.
  At the concave  edge  of the  Kidney, the Artery di-
 vides into three or four Branches,  which  sometimes
 sends Twigs to the Glandula Renalis and  Tunica Adi-
 posa ofthe Kidney.
  Tbe Renal Branches then plunge into the substance
 ofthe Kidney, surround its Pelvis, and afterwards rami-
 fy chiefly in its Cortical Substance -—forming Arches
 with each other, but  few in number, at the roots ofthe
 Papillx.
  The Vena Renalis, or Emulgens, terminates in the In-
 ferior Cava ; and is more superficial than its correspon-
 ding Artery.  It  is the largest Vein  received by the
I Cava from  its origin  to the part where it  reaches the
SLiver.
  The left  Renal Vein is the longer of the two ;—the
 Aorta, before which it passes,  being situated between
 the Cava and left Kidney.
  Arteri* Capsulares. £ The Arterix Capsulares, or Ar-
 teries ofthe Renal Capsules or Glands, are small  but nu-
 merous.
  They are derived from the Renal and Diaphragmatic
 Arteries; and, in general, the left  Renal Gland re-
 ocivcs additional Branched from the Trunk ofthe Aorta.
  The  Ven* Capsulares commonly  unite  into  a large
 Trunk, which, in  the lift side, terminates in that ofthe 
256
Kidney, while in the right  it frequently goes into the
Cava.
  Arteria Adiposa.   The Arteries which supply the Tu-
nica Adiposa of the Kidney, are numerous Twigs pro-  '
ceeding from the Diaphragmatic, Capsular, and Renal  '
Arteries, or form others near it.
  The veins which return from the extremities of these  >
Arteries pass into the Trunks adjacent                w
  Arteria Spermatica-   The  Spermatic Artery, the dia- W
meter of which is small when compared with its great  \
length, arises opposite to its  fellow, from  the fore-part' i
ofthe Aorta, a little below the Renal Arteries.        <
  Sometimes it arises from the  A.  Renalis, at other .'
times a little higher from the Aorta, and in rarer instan-  *
ces from the Diaphragmatic Artery.
  It descends, in a waving direction, on the surface of
the Psoas  Muscle, covered by the  Peritoneum ;  the  <
right passing obliquely over  the Cava, the left behind
the Colica Arteries of the same side, and both before  '
the Ureters to the under part ofthe Abdomen.
  After this, it  perforates the Ring of the Obliquus Ex-
ternus, and runs in the Spermatic Cord,  where it di-
vides into Branches which are dispersed in a very con-
voluted manner upon the Testicle and Epididymis.      '
  In the descent of the Artery it imparts—             <
  Twigs to the Tunica Adiposa of the Kidney.
  To the Peritoneum  and Cellular Substance near it;  '
—and                                              «
  To the Ureters,—which are also supplied with other  j
Arters from the adjacent Vessels, viz- from the Renal
and Capsular Arteries, from the Aorta, the Iliacx  and  •<«
Vesicales.                                            '
  The vena  Spermatica is much larger than its corres-  ,
ponding Artery, and is furnished with Valves  within,  ^
but more particularly without the Abdomen.
  It forms a Plexus which accompanies the Artery,  and
about the place where it recedes from it, which is near-
ly opposite the under end ofthe Kidney, it forms a  sin-
gle Trunk,   which in  the right side goes into the Cava
a little below the Emulgent*Vein, and in the left into   I
the corresponding Vena Renalis.
  Besides the Artery commonly termed Spermatic, the
Testicle generally receives a Minute  Branch, .which a- 
257
rises from the Hypogastric, and accompanies the Vas
Defarens to the Body of the Testicle upon which it is
dispersed,—communicating there with  the Branches of
the Spermatic Artery.
  The vein proper to this Artery, terminates in the Ve-
na Hypogastrica.
  The Spermatic Artery,  in the female, has  the same
kind of Origin, and the same course through the Abdo-
men as in the  male ;—but  in place  of perforating the
Abdominal Ring, as it does in the latter, it descends in-
to the Pelvis, between the Lamina of the Ligamentum
Latum, to be  dispersed first upon the Ovarium  and U-
terine Tube, and then upon the body of tbe Uterus it-
self,—passing in at its corner, and communicating with
the Artery ofthe opposite side.
  The Spermatic Vein has the same termination in the
female as in the male,—but is considerably larger.
  Arteria Iliac*. The Iliac Arteries consist ofthe Two
Common  Iliacs, which are formed by the Bifurcation of
the Aorta ; and of the External and Internal  Iliacs of
each side, which are formed  by the Bifurcation of the
Iliacx Communes.
  The External Iliac passes out of the Abdomen be-
hind the  Ligament of Poupart ; the Internal, termed
also A- Hypogastrica, descends obliquely  into  the Pel-
vis.
  At the side  of the Pelvis, the internal divides into
many  Branches, some of which belong to the Organs of
Urine and Generation, the rest  to  other  parts  of the
Pelvis and adjacent parts ofthe thigh.
  The following are the Branches sent from the Hypo-
gastric Artery to the  Organs of Urine and Generation.
  Arteria Umbilicalis.   The  Arteria Umbilicalis ap-
pears  in the Foetus, as the continued Trunk of the Inter-
nal  Iliac ; but iu the  Adult, is shrivelled in the form of
a Ligament, excepting at its beginning or  under  part.
  The beginning ofthe Umbilical Artery gives off-
  One or more Arteri* vesicalis, which run to the under
part ofthe  Bladder, and extend along its sides as far as
the  Fundus Vecicx.   At theirorigin, they furnish Twigs
to the Vesiculx  Seminales, Prostrate Gland, and Rec-
tum.
*-
   P  2 
258
  In the female, the  Umbilical  Artery sends minute
Branches to the Uterus and Vagina.
  Arteria Uterina.  The Arteria Uterina,  termed also
Uterina Hypogastrica,  is much larger than the Sperma-
tic Artery.
  It arises from the Hypogastric, near the  origin ofthe
A. Pudica, and runs into the Uterus at its  under extre-
mity.
  It is afterwards reflected upwards  along the edge of
the Uterus, towards its Fundus or upper part, where it
meets with the Spermatic  Artery, with which it forms
frequent Anastomoses, and afterwards many communi-
cations with the Uterine Artery of the opposite side.
  The Uterine Artery sends Branches  downwards to
the substance ofthe Vagina, and others forwards to be  (
dispersed upon the Bladder.
  Arteria  Vaginalis. The Arteria Vaginalis is frequent-
ly awanting.—When present, it arises from some of
the Branches of  the Hypogastric,—as that common to
the Ischiatic and Pudic,—or from the Hxmorrhoidalis  :
Media ; and is distributed upon the under part of the  '
Vagina.
  Besides this, there  are other Vaginal  Branches from
the neighbouring Arterie's ; as from the vesicates, Uteri-
na,  and Pudica, which  communicate  with each other,
and with the proper Vaginalis,  upon the  substance of
the Vagina.
  Arteria  Pudica, or Pudenda Communis-—The Arteria
Pudica, named from its belonging to the Parts of Gene-
ration in both sexes, comes off either immediately from  \
the  Trunk of the Hypogastric, or form the  A. Ischia-
tica.
  It passes out of the Pelvis, through the under part
of the Notch of the Os Ilium, at the lower edge of the
Pyriform  Muscle.
  It then  turns between the Sacro-sciatic Ligaments, to
get to the inner  side of the  Tuber Ischii, where  it is
lodged deep in the Cellular Substance.
  From the Tuber, it proceeds along the inner side of
the Crus of the  Os Ischium  and of the Os Pubis, and
behind the Crus of the Penis, till it  approaches the
Symphysis ofthe Pubis. 
259
     In its course, it sends off many Branches,  of which
  the following are the principal, viz.—
     Brandies  to the Vesiculx Seminales, Prostate Gland,
  Neck ofthe Bladder, and Rectum.
     Branches of the Muscles and parts adjacent to the
  Sacro-sciatic Ligaments ; some of them extending as
  far as the joint ofthe Thigh-bone.
     Branches to the Muscles,  Membranes,  and Fat about
  the Tuber of the Os Ischium.
    The Arteria H*morrhoidalis Externa, which soon di-
  vides into Branches, to supply the Muscles and Integu-
  ments about the verge ofthe Anus.
    The A. Perinei, which  passes under the Transversalis
  Perinei Muscle,  in the space between  the Crus of the
  Penis and Bulb of the Urethra, and gives Branches to
  the Skin  and  Muscles at  the fore-part ofthe  Anus and
  root of the Penis, and to the Scrotum; while  the Ar-
  tery itself terminates on the under side  of the Penis.
    After  dispersing the  Branches already mentioned,
  the Pudic Artery divides, at the Penis, into three prin-
  cipal Branches, viz.—
     The First Branch, which passes into  the Bulb of the
  Urethra, and is continued forwards in the  Corpus Spon-
  giosum Urethrx, into tlie Cells of which many of its
  Branches open.
    The Second Branch, termed  Profunda  Penis, which
  goes into the Crus Penis, and directs its course in the
  Corpus Cavernosum ; its Branches communicating with
  the Artery of the opposite  side, and with the Cells of
  tlie Penis.
    The Third Branch, called Dorsalis Penis, which turns
' I between the Symphysis  of the Pubis and root of the
  Penis, and proceeds  along  the  Dorsum,  as far as the
  Glans, adhering closely to the Ligamentous Substance
  which incloses the Corpora  Cavernosa,  and  sending
  Branches to it and to the Integuments.
    In the female,  the  Pudic Artery has tire same gene-
  ral course as in the male.
    After reaching the inner side  ofthe  Tuber ofthe Os
  Ischium, it is extended forwards, and  sends Branches
  to the Anus, Perineum, end of the Vagina, and Labia
  Externa, and terminates in  the  Clitoris,  somewhat in
  a similar manner as in the Penis.
                        p 3 
260
  The Blood is returned from the Branches of tlie Hy.
pogastric Artery dispersed  upon  the  Organs of Urine
and Generation, by tbe following Veins, viz.
  The Vena Vesicalis, which returns the Blood from the
Bladder
  The Vena Uterina Hypogastrica, which comes from the
Uterus
  The Vena Magna Ipsius Penis, which runs along the
middle ofthe Dorsum, and is often double to near the
root of  the  Penis;  after  which it  passes between
this and the Arch of the Pubes. forming a Plexus which
surrounds the Neck of the Bladder, and sending out
Branches which terminate in others at the sides of this
Viscus.
  The  Vena Pudica,  which communicates anteriorly
with the Branches of  the Vena Magna  at the root of
the Penis, and afterwards passes back with the corres-
ponding Artery.
  The Vena Tegmentorum  Penis, which  is formed by
small Subcutaneous Branches, and ends in  the top of
the Femoral Vein.
  The Veins above mentioned, the last excepted, ter-
minate in the Hypogastrica, along with other Veins be-
longing to the Pelvis, to be afterwards described.  »
             BLOOD-VESSELS

Ofthe CONTAINING parts ofthe abdomen, and

   ofthe pelvis and inferior extremity.

  Arteri* Lumbares.—The Lumbar Arteries, which are
commonly four in insmber on  each side, arise in pairs
from the back-part ofthe Abdominal Aorta, in the same
manner as the Intercostals do from the  Aorta in the
Thorax.
  They run first over the fore-part ofthe Bodies of the
four uppermost Lumbar Vertebrx, and afterwards go 
251
 between  them and the Psox Muscles, in their way to-
 wards the sides ofthe Abdomen.
   They give Branches to the Spine, to the Spinal Mar-
 row and its Membranes ; are particularly dispersed up-
 on the Lumbar Muscles, and upon the Transversus and
 Obligui Abdominis;  and perforating these, they also
 furnish Branches to the large  Muscles and the Integu-
 ments in the back-part of the Loins.
   Superiorly, they communicate with the lower Inter-
 costal and Diaphragmatic Arteries.
   Sacra Media.  The Sacra Media  is  a  small  Azygos
 Artery, which arises from the under and back-part of
 the Aorta, immediately at its Bifurcation.
   It generally sends off a Branch over each side ofthe
 last Vertebra ofthe Loins, which takes nearly tbe same
 course backwards with the  Arterix  Lumbares.
   The Sacral Artery afterwards descends along the
 middle ofthe Sacrum, as far as the Os Coccygis, send-
 ing Branches to the Membranes and Substance of these
 Bones, and to the back-part ofthe Rectum.
   Iliac* Communes.   After giving off the Arteries of
 the contents and ofthe containing parts of the Abdomen,
 the Aorta, upon the under part of the Fourth Lumbar
 Vertebra, divides into the Two Common Iliac Arteries,
 which are of equal size.
   They pass obliquely downwards and outwards; and
 at the under and lateral parts of the last  Vertebra of
 the Loins, *'. e. opposite to the posterior  Symphysis of
 the Pelvis, each divides into two  others, an Anterior,
termed Iliaca Externa, and a Posterior,  termed lliaca
Interna, or Hypogastrica.
  Iliaca Externa.  The Iliaca Externa, which appears
in the Adult as the continuation ofthe  common Trunk,
descends along the Brim of  the Pelvis,  taking a curved
direction by the side of the Psoas Muscle, and after-
wards passes behind the Ligament ofPou part, to form
the Femoral Artery.  •
  In this course, it does not send off any Branches, ex-
cepting sometimes a Twig or two to the Peritoneum,
Psoas Muscle, kc. till it is about to leave the Abdomen,
where it gives rise to two principal Arteries,—the Epi-
gastrica, and Circumflexa Ossis Ilti.
  The Arteria Epigastrica, obtaining its name from its
                       P  4 
262
situation in the fore-part ofthe Belly, goes off from the
inner side of the  Femoral Artery,  immediately before
that Vessel gets behind the Ligament o/Poupart.
  At its origin, it is a little bent downwards, and about
half an inch from  the place where it first comes off, it
crosses  obliquely  upwards  and inwards, behind the
Spermatic Cord in the male, and round Ligament in the
female.
  It proceeds in this oblique manner behind the Tendon
ofthe Transversus, till it reaches  as high as the point
of the Pyramidalis, after which it takes a perpendicular
direction  along the back-part of the Rectus Abdominis
Muscle.
   It furnishes Branches to the  Muscles, Integuments,
and Membranes of the fore-part ofthe Abdomen, com-
municates in several places with the Lumbar Arteries,
and terminates a Utile above the  Umbilicus, where it
forms several distinct though small Anastomoses with
the under end ofthe Mammaria Interna.
   Circumflexa Ossis Ilii.—The Circumflex Artery ofthe
Ilium, almost as large as the Epigastric  Artery, arises
nearly opposite to it, though frequently a little lower,—
immediately behind the  under end of the Follopian Li-
gament.
   It runs at  the under edge of the Os Ilium, till it ar-
rives near the Vertebrx of the Loins.
   It gives Branches to the Psoas and Iliac Muscles, to
the under end of the Oblique and Transversus Abdomi-
 nis, and at length communicates with the Epigastric, and
 with the inferior Arteries ofthe Loins.
   Iliac Interna-   The Iliaca Interna, or Hypogastrica
 passes downwards and backwards in the posterior and
 lateral part ofthe Cavity ofthe  Pelvis, for about a cou-
 ple of fingers breadth, after which it generally divides
 into a posterior and anterior Set of Branches;  the for-
 mer supplying the parts nearest the Sacrum and Illium,
 tbe latter belonging more immediately to the parts about
 the Anterior region of the Pelvis.
                  Posterior Branches.
   Ilco-Lumbaris, or  Iliaca Interna Minor.  The Ueo-
 lumbar is a small Artery, arising  sometimes from the
 end of the Hypogastric,  at other times from the" begin-
 ning of thx* Glutea 
203
  It passes outwards under the  Psoas Muscle, and di-
vides suddenly  into Branches, one of which frequently
forms a kind of Lumbalis Ima.
  The  other Branches go to the Psoas,  and Iliacus In-
ternus Muscles, communicating there with the Lumbar
Arteries and Circumflex Branches of the Ilium ;—a par-
ticular Twig constituting an A.  Nutritia, or  Medullars of
the Os Ilium.
  Sacr* Laterales.  These are generally two or three in
number, arising from the common Trunk,  or frequently
from the Gluteal Artery ;—though sometimes, there is
only a single Artery, which descends by the sides ofthe
Sacral Holes, giving Branches, which supply the place
ofthe Sacrx Laterales, and sometimes also ofthe Sacrx
Media.
  They  furnish Branches to the Membranes on the sur-
face of the Os Sacrum, and  inosculate by cross Twigs
with the Sacra Media.
  Their principal Trunks enter the anterior Sacral Holes
to be distributed upon the  Cauda Equina and the Mem-
branes and bones inclosing it.
  Arteria Glutea.  This is sometimes termed Iliaca po-
sterior, and is the largest Branch of the Hypogastric Ar-
tery.
  Soon after it arises, it passes through the upper part of
the great Notch of the  Os Ilium, and is  reflected over
the edge of the Bone, in the manner of the Inferior Sca»
pulary Artery.
  At the under edge of the Gluteus  Medius, it is divided
into two sets of Branches, one of which runs in a radia-
ted direction close upon the Bone, and is chiefly dispers-
ed upon the two smaller Glutei, while Branches of infe-
rior size run some  of them  downwards to the Muscles
and Ligaments about the Joint of the Thigh, and others
backwards to the parts about  the Sacrum, communicat-
ing with the Lateral Sacral Arteries through the Posterior
Foramina ofthe Os Sacrum.
   The other set of Branches of the Gluteal Artery creeps
in between the Gluteus Medius and Maximus Muscles,
upon the latter of which it is chiefly dispersed.

                   Anterior  Branches.
■   Anterior Obturatoria, or  ObturatHx.—The Obturator 
264
 Artery has its origin from the Trunk ofthe Hypogastric,
 or from the Ileo-lumbar, or from the Ischiatic, and some-
 times from the end of the Iliaca Externa.
   It descends in the Pelvis by the side of the Psoas Mus-
 cle, and afterwards passes through the Hole at tbe up.
 per part ofthe Obturator Ligament.
   While in the Pel\ is, it  frequently gives  Twigs to the
 Bladder and other parts near it.
   After perforating the  Ligament, it divides into Bran-
 ches, one set of which are dispersed upon the parts about
 the  Hip-joint, while another belongs to the  Obturator
 Muscle, and to the Muscles which are situated at the up-
 per and inner part of the Thigh,—the two sets of Bran-
 ches inosculating with each other.
   Arteria Umbilicalis.—The Umbiliealis Artery sends off
 Rami Vesicales from its  under part or beginning; the
 rest of it, in the Adult,  being shrivelled into Ligament,
 as already observed.
   Vesicalis Ima of  Haller.—This is  a long and slender
 Branch which frequently comes off from the root of the
 Pudica, and runs to the under  part of the Bladder, and
 to the Prostate Gland.
   Arteria Uterina-  The Uterine or Uterine-Hypogastric
 Artery, is dispersed upon tlie Uterus, as has been already
 described.
   H*morrhoidalis Media-  The middle Hxmorrhoidal
 Artery  is sometimes sent  off from the original Trunk,
 and at other times from some of its Branches, as the Pu-
 dic in the male, or Umbilical in  the female.
   It is chiefly distributed upon the lower end ofthe Rec-
 tum, where it anastomoses with the Hxmorrhoidalis In-
 terna.   It frequently  sends Branches to the under part
 ofthe Bladder, to the Vesiculx Seminales and  Prostate
 in the male ; and to the Vaginia and Bladder in the fe-
 male.
  Pudica Communis.—The  Pudica Communis, termed
 by some Authors H*morrhoidalis Externa, belongs to
the parts of Generation and Anus, as was formerly taken
notice of.
  Arteria Sciatica-  The Sciatic, or Ischiatic Artery is
the largest of the Iliac Branches, the Glutea excepted.
  It goes through the under part of the Sciatic Notch, 
203
accompanied by the Nerve of that name, having the py*
riform Muscle between it and the Gluteal Artery..
  It afterwards descends someway down the Thigh, in
company with the Sciatic Nerve, in the hollow between
the great Trochanter of the Thigh-bone and Tuber of
the Ischium,—covered by the Gluteus Maximus Muscle.
  It sends an Artery backwards, termed  A.  Coccygeal.
which creeps along the Sacro-Sciatic Ligaments furnish-
ing Branches to the parts about the Os Coccygis, and o-
thers which ascend from it, and anastomose with some
ofthe Lateral Sacral Arteries through the Holes in the
back-part ofthe Os Sacrum.
  The principal Branches of the Sciatic Artery, however,
are dispersed upon the under part of the Gluteus .Maxi-
mus Muscle, and upon those at the upper and back-part ■
of the Thigh, where they communicate with the Obtura-
tor and Pudic Arteries.

                 Arteria Femoralis.

  The Femoral or Crural Artery, the continuation.of the >
External Iliac, passes out of the Abdomen between the
Ligament of Poupart  and Brim of the Pelvis.
  At its first exit, it is situated superficially over the
Ball ofthe Os Femoris,  having the Flexors of the Thigh
between it and the joint.
  Farther down, it is lodged deep in a hollow at the up-
per and inner part ofthe Thigh, having the Rectus and
Sartorius upon the outer, and the Adductores  Femoris
upon the inner side of it.
  Here, it is covered by the Glands of the Groin,  and
by the general Aponeurosis and Fat; and from this part
it descends at the inside ofthe Thigh turning gradually
backwards till it reaches the Ham.
  From the top of the Femoral Artery, a  few small
Branches are sent off to the Superficial Muscles and In-
guinal Glands, and to the common Integuments at the
upper part of the Thigh ; also one or two others termed
Pudica Extern*, to the External parts of Generation and
Integuments ofthe inside ofthe Thigh-
   About two Fingers-breadth below the Ligament of
Poupart, the Femoral Artery divides, somewhat like
the Common Iliac, into  Anterior and Posterior parts:— 
                       266
The former is the Femoral Artery strictly so called, tlie
latter is termed Profunda Femoris.

                 Profunda Femoris.

  The Arteria Profunda, also called vasta,  posterior, or
Muscularis Femoris, immediately at its origin from the
Femoral Artery,  gives off two large Branches, —the
Circumflexa Interna, and  Circumflexa Externa,—which
run in opposite directions at the upper part of the thigh. ■
  The Circuinflexa Interna, though most frequently com-
ing off from  tne beginning of the Profunda, often arises
higher than it, from the top ofthe Femoral; and there
are now and then two of them, one a little lower than'
the other.
  It passes between the under end ofthe Psoas, and the
Pestinalis Muscle, and afterwards turns round the inner
part of the joint ofthe Thigh.
  It sends off—
  Large Branches to that portion ofthe Adductor Mus-
cles which belongs to  the upper part ofthe Thigh.
  Small Branches to the Muscles in the  vicinity cf the
Trochanters.
  A Branch termed Articularis Acetabulia to the Capsu-
lar Ligament ofthe Joint.
  A Twig, which enters the breach at the under and 1
fbre-part ofthe Acetabulum, to be dispersed upon the i
Ligamentum Rotundum, and the substance called gland \
ofthe Joint.
  A considerable Branch, which anastomoses with the
trunk ofthe Obturator Artery  :—And
  Smaller Branches, which communicate  with the Arte- '
ria Sciatica.
  Circumflexa Externa.—The Circumflexa Externa ari-
ses from the most part nearly opposite the former, but ••'
frequently a little lower.—Now and then this Artery has ,
a double Origin, one of the Trunks  coming off higher
than the other.
  It passes outwards between the upper ends of the Rec-
tus, Tensor Vaginx Femoris, and Vastus Externus Mus- i
cles, and over the Great Trochanter of the  Os Femoris. -m
  It sends Branches upwards  to the under part ofthe |
Glutei and to otlier  Muscles placed  at tlie inferior'and 
267
  back part of the Pelvis, which anastomose  with those
  running down from the Arteria Sciatica.
    Others which have more of a lateral direction, and are
  distributed upon the Muscles at the upper and back-part
  of the Thigh,  and  upon those more immediately about
  the  Joint,—communicating with the Branches of the
  Circumflexa Interna.
    The largest Branches descend between the Rectus Fe-
  moris aud Vastus Externus ; one, longer than the rest,
  reaching almost as far as the outer part of the Knee.
    The Profunda Femoris, having detached the Circum-
  flex  Arteries, sinks deep behind the Trunk of the A.
'  Femoralis, and is situate upon the Adductor  Muscles of
  the Thigh.
    In its descent it is  divided into principal  Branches,
  termed Rami Perforantus, which after sending off small
  Branches to the Triceps Muscle, perforate it to be dis-
  persed upon the Flexors on the back part of  the Thigh.
    The  Perforantus come off in the  following succes-
\ sion, viz.
    The Perforans Prima, which arises near the small
  Trochanter, perforates the Triceps a little farther down
  and furnishes Branches to the Muscles in the upper and
  back-part ofthe Thigh.
    It  forms numerous Communications with the Circum-
  flex Arteries, about the root of the Great Trochanter,
  and anastomoses in particular with the under end ofthe
■  Sciatica.
    ThePerforans Secunda or Magna, which comes off some
  way below the former, and is the largest of the perfora-
 ' ting  Arteries.
    It  gives Branches to the Muscles in general about the
  middle of the  back-part ofthe Thigh,  particularly to
  the Flexors ofthe Leg; and communicates above with
  the Arteries of the Perforans Prima, and with the Cir-
  cumflex Arteries.
    Besides these, there is one, and sometimes two oth-
  er perforating Branches, which are greatly  inferior in
  size to tho two former, and are lost upon the Flexors at
  the under and back-part of the Thigh ;  one  Twig sent
  off from these  sometimes forming a Nutritia or Medul-
* laris ofthe Os Femoris.
    The Femoral Artery, after giving off the Profunda Fe- 
268
 moris, passes down between the Vastus Internus and In-
 sertion ofthe Triceps, giving only small Branches to the
 adjacent Muscles and Integuments.
   About the middle of the inside ofthe Thigh, it is si-
 tuated behind  the  Sartorius Muscle ; and nearlv two
 thirds down upon the Os Femoris, it perforates the Tri-
 ceps, passing between that Muscle and the Bone, in its*
 way to the Leg.
   Having passed through the Triceps, it is found in the
 back-part of the Thigh, where it sends Branches, some-
 times termed Perforantus, to the Flexors and Integu-
 ments, one Branch  the principal Medullaris, to the sub-
 stance ofthe Bone, and others to each ofthe Vasti Mus-
 cles,  the Muscular Branches communicating above with
 Branches descending from superior parts of the Thigh.  .
 In this part of the thigh it lies close upon the Bone, and
 adheres firmly to it, till it reaches tbe Ham, where it is
 termed A.  Poplitea.

                   Arteria Poplitea.

  The Arteria Poplitea is lodged deep in the hollow he.  ,
 tween the  Ham-strings, and between the  Condyles of
 the Os Femoris, covered by its associate Vein and Nerve
 and generally by a great deal of Fat.
  I gives off several Branches, termed Articulares Supe-  i
 riors and Inferiors, to the Joint of the Knee.            i
  Four of these, situated, two above  and two below tbe
 Joint, are more regular and constant than the rest, viz.
  The Articularus Superior Interna, which turns round
 tbe Os Femoris, above the Inner Condyle, passes under  j
 the Semimembranosus and Semitendinosus ; and, after '
 perforating the Tendon ofthe Triceps Muscle, is disper-  ■
 sed upon the upper and inner part of the Knee, anasto-
 mosing above with Branches sent down from the Femo-
 ral Artery.
  The Articularis Superior Externa, which arises nearly
opposite the former, passes outwards between the Ten- (
don ofthe Biceps and Body ofthe Oa Fomoria, imme-'
diately above its outer Condyle, and is lost upon the up-j
per and outer part of the Knee ; its Branches anastomo-^
 sing with those of its fellow, and particularly with the
 long descending Branch of the Circumflexa Externa. 
269
     'The Articularis Inferior Interna, which arises opposite
   the bending of the Joint, passes downwards, and then
   turns round the Tibia, immediately below its inner Con-
   dyle.
     It sends Branches first to the back-part, then the in-
   ner side ofthe Knee ; some of them insinuating by the
   Semilunar Cartilages into the inner part of the Joint.
     It communicates above with the Branches ofthe Ar-
   ticularis Superior Interna.
     The Articularis Inferior Externa, which comes off near
   the former, and passes first downwards, then outwards,
   between the External Lateral and the Capsular Liga-
   ment, to be dispersed upon the under and outer part of
   Knee and inner part of the Joint; communicating with
   its fellow ofthe opposite side, and above, with the Bran-
   ches of the Articularis Superior Externa.
     The other less constant Articular Branches are dis-
   persed upon the  Muscles a little above the Joint.
     The Arteria Poplitea, having furnished Branches to
   the Joint of the Knee, gives others to the Muscles at the
   upper and back-part of the Leg,  two of which termed
   Surales, more considerable than the rest, pass into the
   heads ofthe Gastrocnemius Externus.
     The Trunk of the Artery passes afterwards between
   the heads ofthe external Gastrocnemius and commonly
   from, two to three inches below the bending ofthe Knee,
   and at the under and outer edge of the Popliteus divides
   into two large Arteries, the Tibialis Antica,  and Tibia-
   lis Fostica.
     Tibialis Antica—The Tibialis Antica passes directly
,   through the upper end ofthe Interosseous Ligament to
   the fore-part of the Leg.
     In its descent in the Leg, it adheres closely to the an-
   terior  surface of the Interosseous Ligament; and has
   the Tibialis Anticus on the inner side, and the Long Ex-
   tensors of the Toes on the outer.
     A little above the Ankle, it passes upon the outer and
 .-*• fore-part ofthe Tibia, and getting under the annular li-
   gament aad extensor Pollicis, it goes along the  convex
   surface ofthe Foot.
     It supplies, in general, the Muscles and Integuments,
   which belong to the outer and forepart ofthe foot, and
   ultimately pa^es into the deep Muscles ofthe Sole. 
                        270
   Its branches come off in the following order, viz.—
   A small Branch sent off before the Trunk perforates
the Interosseous  Ligament, to be  dispersed upon the
parts near the Joint; the superior Twigs running in a
retrograde direction.
   The Recurrens Anterior, which arises from the Artery
after it has perforated the Ligament, and is distributed
upon the Muscles at the upper part of the Leg, and up-
on the Ligaments at the  under  part of the Knee, anas-
tomosing there with the Inferior Articular Arteries.
   Numerous Branches sent off in a lateral direction to
the Muscles and integuments on the outer and fore-part
ofthe  Leg.
   The Molleoli Interna, which comes off near the lower '
end of the Tibia, and is dispersed on the parts about
the inner Ankle.
   The Malleoli  Externa,  which arises a little lower
than the former, and is distributed to the parts near the
outer Ankle.
   The Arteria Tar sea, which takes its origin a little an-
teriorly to the bending of the Ankle-joint, and is  more
considerable in size than the Malleolar Branches.
   It passes obliquely outwards  and forwards  under the
Extensor Brevis Digitorum, and sends Branches to the
Joint of the Ankle, where it communicates with the
Malleolar Arteries.
   It supplies the greater part of the Muscles, Integu-
ments, &c. on the upper and otiter part ofthe Foot, and
sends branches termed Interossei, to the Muscles be-
tween the Metatarsal bones of the small Toes,—which,
however, are frequently derived from the Metatarsal
artery.
   The Arteri* Metatarsea, which goes off about the mid-
dle ofthe Dorsum Pedis, and passes obliqnely towards
the root  of the Little Toe,  assisting the former  artery
in furnishing Branches to the upper part  of the Foot and
Toes, and sometimes, in part or entirely supplying the
place of that artery.
  The remaining part of the anterior Tibial artery after-
wards advances between the Extensor ofthe great, and
long Extensor ofthe small Toes, sending Twigs to the
adjacent  parts, and  dividing, between tfxe Metatarsal 
271
  Bones of the Great Toe and that next it, into a Large
  Posterior and a Smalt Anterior Branch.
    The Posterior Branch, which may be considered as the
  continuation ofthe Trunk, sinks between the Metatarsal
  Bones of the two first Toes, and anastomoses with a
  deep Artery in the Sole.
    The Anterior Branch runs forwards, under the name of
  Dorsalis Pollicis, to be dispersed  upon  the Great and
  Second Toes.
    Tibialis postica.—The Tibialis  Postica divides about a
'  finger's  breadth under the origin of the Tibialis  Antica,
>  into the Fibularis, and Tibialis Postica strictly so called.
    The Fibularis, termed also  Peronea, whicli  is smaller
->  than either of the Tibial Arteries, runs down  at the in-
  ner side ofthe Fibula, for a considerable  way  along the
  Leg, and is situated, first under the Soleus, and then un-
>  der the Flexor Longus Pollicis.
    Its Branches are distributed to the Muscles at the out-
  er part of the Leg in the neighbourhood of the Fibula,—
  a &mall Medullary Branch also penetrating tlie  substance
r  of that Bone.
     A little above the interior Articulation ofthe Tibia and
  Fibula,  it sends a Branch forwards, termed  Peronea An-
  terior, which perforates the Interosseous Ligament, and
  is dispersed upon the  fore part of the Ankle, where it
  anastomoses  with the  External Branch of  the  Tibialis
;  Antica.
    The continuation  of the Trunk, sometimes termed Pe-
  ronea posterior, descends behind the Malleolus Externus,
  to the outer and back-part of the Foot, anastomosing with
  the External Malleolar and Tarsal Branches  of tlie Ti-
  bialis Antica.
    The Jibialis Sostica, propedy  so called, passes down
  at the back-part of the Tibia, and runs over the Tibialis
  Posticus and Flexor Digitorum,  and  under  the Gastroc-
  nemius  Internus,  in its descent through the Leg.
     Behind the inner Ankle, it becomes more superficial,
  and has the Tibialis Posticus  and  Flexor Digitorum Lon-
  gus on the  inner, and the  Flexor  Longus Pollicis on the
  outer side of it.
     From the  Ankle, it runs in the Hollow of the Os Cai-
  ns, and behind the Abductor Pollicis, to the  Sole ofthe
  Foot.
vol.. -vll
O 
2r2
  Its Branches supply the Muscles at the back and inner
part of the Leg, and the different parts ofthe Sole ; form.
ing  many Inosculations with the Branches of the ante.
rior Tibial and the Fibular Artery.
  In its course along the Leg, it gives off—
  Numerous  Branches, similar to those of the  Tibialis
Antica, to the surrounding Muscles :
  The Arteria Nutritia Tibi*, which begins a little below !
the upper end of the Trunk, descends  for some way in
the  Leg, and gives Branches  to the deep Muscles and
Membranes near it, and one Branch termed A. Medulla-
ris,  which enters the Hole near the middle of the Bone. ■
  Several Branches to  the parts behind, and at the inner
side ofthe Ankle and  Heel, which communicate witho-
thers oftfie Anterior Tibial Artery.
  The Trunk ofthe Artery divides in the  Hollow of tlie
Os Calcis, at the place where it is about to  go behind tlie
Abductor Pollicis, into two principal Plantar Branches,
—the Interna aud the  Externa-
  The Plantar Arteries run forwards under the Aponeu-
rosis Plantaris, having the Flexors of the  Toes between
them.
  The Plantaris Interna passes near the inner side ofthe
Sole, between the  Aponeurosis Plantaris and Abductor
Pollicis.
  It gives Branches which run in a retrogade direction to
the  back-part of the  Ankle and  adjacent parts at the
Heel:
  Several Branches from each side, which go forwards to |
the Muscles and Integuments, and other parts of the con-
cave edge of the Sole.
  Atthe root of  the  Great  Toe,  it sends  a principal1
Branch to its inner side ; it then passes  under the Flexoi'
Longus Pollicis, and after anastomosing with the Arcus
Plantaris, gives off a large Branch which splits into two,
—one to the outer side of the Great Toe, and the other
to the adjacent side of tlie Toe next it.
  The Plantaris Externa,—which may be  considered as^
the  continuation ofthe Trunk, being  in general much lar-l
ger  than the Interna,—passes  obliquely  outwards be-'
tween the Flexor Brevis  Digitorum, and Flexor Acces-
sorius, till it reaches the Base of the  Metatarsal Bone of
the  Little Toe. 
273
  It is afterwards arched forwards between the Flexors
of the Toes and Metatarsal Bones, the  Trunk being con-
tinued to the root ofthe Great Toe, under the name of
Arcus plantaris-
  The  External Plantar Artery sends off—
  A Considerable Branch, first to the under, then to the
outer part of the Heel, which communicates externally
with Branches of the anterior Tibial and the Fibular Ar-
teries :
  Several Branches to the Flexor of the Toes, and to 0-
ther parts in the  outer portion of  the  Sole, which com-
municate, on the inner side,  with the Branches of the
Plantaris  Interna, and at the outer with those of the an-
terior Tibial Artery.
  The  Arcus Plantaris gives out—
  Several Branches to the deep Muscles of the  Sole, par-
ticularly,
  Rami Interossei to the Muscles between the Mctatar-
sal Bones -.
  A Branch to the outer side of the little Toe :
  Three large Digital Arteries, which  are  forked at the
roots of the Toes, and run along the edges of these, in
the manner the Digital Arteries do along the Fingers.
  Between the Metatarsal Bones  of the Great Toe and
the one next it, the Plantar Arch anastomoses with the
posterior  or perforating  Branch  of the anterior Tibial
Artery, forming a free communication  between the Ar-
teries ofthe upper and under  side ofthe foot. Frequent-
ly it sends off here  a  Digital Artery,  which  forks and
runs along the outer side of the Great Toe, and inner side
of the Toe next it, so as to supply the place of one ofthe
Branches of the Internal Plantar Artery.
  At the roots of the Toes,  the Interosseus Arteries of
the upper part ofthe Foot, also form distinct anastomoses
with the anterior extremities  ofthe Trunks of the Digi-
tal Arteries.
                     VEINS*.

  The Veins of the Iferior Extremities,  l.'.-.e those of
the Superior, consist of a Subcutaneous and Lzep set, and
like them also, are furnished with numerous Valves 
274
   Subcutaneous Veins—The Subcutaneous Veins are situ.
 ated between the common  Integuments  and  General
 Aponeurosis, and, in many parts, are entirely concealed
 by the Fat.   They anastomose frequently  with each o-
 ther by large Branches, and have several communications
 also with the deep-seated Veins.
   They form two principal Trunks, called Saphxna Ma.
 for and Saphana  Minor ,•—the term  Saphana applied
 from the Vein being supposed to be always visible.
   The Saphana Major begins upon the upper side ofthe
 Foot, runs over the fore-part ofthe inner Ankle, and as-
 cends in the Leg, at the  inner edge ofthe Tibia.
   From the Leg. it passes up by the inside of the Knee,
 and afterwards, from the inner to the upper and fore-part
 ofthe Thigh.
   It is at first composed of Veins, derived from the upper
 and inner part of the Dorsum Pedis, which have frequent
 anastomoses with  each other, and are of considerable
 size.
   In its ascent it is joined by Branches from the Superfi-
 cial parts of the Leg, and is frequently split into a Plexus
 some way below the Knee.
   It receives Branches from the superficial parts of the
 Thigh,  and small Twigs from the Inguinal Glands-
   It terminates in the top of the Femoral Vein,  nearly
 opposite to,  or a little higher than, the origin of tbe Ar-
 teri:i Profunda.
   The Saphana Minor arises from  the outer side ofthe
 Foot, and afterwards passes behind the Malleolus Exter-
 nus.
   From this, it ascends in the back-part of the Leg, up-
 on the curface of the Gastrocnemius Externus, and goes
 into the Ham.
   It is formed by the Veins of the upper and outer part
 ofthe Foot, and is joined  to the Saphxna Major, over the
 Metatarsal Bones, by one or more  Arches,  which receive
 a Plexus of Branches into their lower or convex part.
   It is joined by  the superficial Veins of the outer and
back-part of  the Leg, which have frequent anastomoses
with each other, and with the Branches of the Saphxna
 Major.
   It terminates in the Vena Poplitea, and communicates 
                        275
constantly by a small Branch with the Saphxna Major, a
little above the Knee.
  Deep Veins.   The Deep Veins of the Leg, like those
ofthe Fore-arm, run close at each side of their Arteries,
and are double their number, but differ a little  from  the
Radial and Ulnar Veins, in being proportionally larger.
  The Tibial  and Fibular Veins  anastomose  in  some
places with each other, and also communicate with the
Subcutaneous Veins.
  At the upper part of the Leg, they are united toge-
ther, to form the Vena Poplitea, and the union is nearly at
the same place  where the corresponding arteries  come
off.
  The Vena Poplitea adheres closely  to the upper sur-
face ofthe Artery, which it in a great measure conceals,
and is commonly single, excepting a small Vein which
sometimes accompanies and communicates with it.
  The Popliteal Vein receives the  Venx Surales and Ar-
ticulares, and the  Saphxna Minor ; after which it forms
the Femoral Vein.
  The Vena Femoralis receives the Veins which corres-
pond with the perforating Branches of the Femoral Ar-
tery, and passes in through the  Triceps, where the Ar-
tery comes out.
  In the middle of the Thigh, it lies deeper than the Ar-
tery, afterwards  turning gradually to its inner side ; and
at the upper part of the Thigh,  it  is joined by the Vena
Profunda.
  The Vena Profunda receives the  Veins  corresponding
with the  Branches of the  Artery  of that name, and is
sometimes of a large size, being then in a great measure
the continuation of the Vena Poplitea, a small Vein  only
in such cases  accompanying the Trunk of the Femoral
Artery.
  Besides the Vena Profunda, the  Femoral Vein takes in
small Ve'ns  from the External parts of Generation, from
the Inguinal Glands,  and from the other superficial parts
ofthe Groin :—and, in particular, it receives a Branch of
considcraMe size, which descends from the Integuments
ofthe fore-side  ofthe Abdomen.
  The Tnoik of the Femoralis, having received the dif-
ferent Veins of tlie  Inferior Extremity, passes into the
Abdomen, bchin 1 Poupart's Ligament, h"'v :r still situ,-*
                        <^2 
                         276
 ated at the inner side ofthe Artery,—after which it forms
 the Iliaca Externa.
   The Iliaca Externa receives into its beginning the Epi-
 gastric, and Circumflex Vein ofthe Os Ilium, and some-
 times the V- Obturatrix.
   It is situated at the inside of the External Iliac Artery,
 and afterwards crosses behind it on the right, and behind
 the Internal Iliac Artery on the left side of the pelvis, to
 join the Trunk ofthe Hypogastric Vein.
   The Vena  Hypogastrica, or Iliaca Interna, is situated  ;
 atthe outer side of the Artery and  receives the differ-
 ent Veins which correspond  with the Branches of the
 Hypogastric Artery, and which are furnished with Valves -\
 where they are situated among the Fleshy parts of the
 Pelvis.
   The External and Internal Iliacs unite and form the
 Common  Iliacs, a little below the division of the cor-
 responding Arteries.
   The Iliaca Communes ascend by the right side of their  i
 respective Arteries, and  a little below  the  Bifurcation
 of the Aorta,—or upon the fore-part ofthe  Fifth Lum-
 bar Vertebra,—unite to form the  Inferior Cava, situa-
 ted, as formerly  mentioned,  at the right  side of the  <
 Aorta.                                                *■
   The Vena Cava Inferior,—which is much larger than
 the Cava Superior, and greatly exceeds in size the de-
 scending  Aorta,—receives, at its  beginning, the Vena  ■
 Sacra, and higher, the Venx Lumbares, which, in the
 left side, pass behind the  Trunk of the Aorta.
   It likewise receives the Venx Renales, and the Sper-  !
 matic of the right side.
   At length it takes in the Venx Hepaticx and  Dia-  !
phragmaticx,  and perforating  the Diaphragm at the
root ofthe Liver, it terminates in the Right Auricle of
the Heart. 
PART VII.
OF THE NERVES IN GENERAL.
  THE Nerves are firm, white Chords, which are gen-
erally considered  as being directly continued from the
Medullary Substance of the Brain and Spinal Marrow;
—although instances have  been frequently  met with,
where the  Brain,  and  even the Spinal Marrow, have
been found nearly obliterated in the Foetus, and yet the
Nerves retained their usual appearance.
  They are composed of Funicula closely connected, and
each of these again of smaller Fibrilla which may be
subdivided into parts so extremely minute, as almost to
elude the naked Eye, but whicli may be readily seen by
the assistance ofthe Microscope :—No Cavity, however,
has been yet observed in them.
  The Medullary Part of the Fibrillx appears to be fur-
nished with a Cineritious Substance derived  from their
Pia Mater; in proof of which, they are observed to be
in general of a browner colour than the Medullary Sub-
stance ofthe  Brain, and larger in their course than at
their supposed origin.—Monro's Obscrv. on Nerv. Syst.
  The Medullary Substance ofthe Fibrillx is pulpy  and
tender, but rendered thicker and stronger by  the cover-
ings they receive from the Tunica  Arachnoidea,  and
Pia Mater, while within the Bones, and more particular-
ly by the additional covering given them  by the Dura
Mater upon their exit.
  The Dura Mater, in its passage through the Base of
the Cranium, and between the different Vertebrx, is con-
nected by its External Surface to the Pericranium  and
Periostium ; while the inner part of it, together with the
Tunica Arachnoidea and Pia Mater, is continued along
the Nerves. 
278
   The  Involucra, or Coverings,  inclose each  of the
 Nerves in general, and likewise the several Fibrillx of
 which they are composed, whereby their size, as well
 as strength, is greatly increased.
   The Nerves, soon after leaving the Bones, have the
 Dura Mater so intimately connected with  them, that
 it has been considered  by some Authors, as degenera-
 ting into condensed Cellular Substance, notwithstanding
 it still retains the general appearance of the Dura Ma-
 ter.
   Upon examining the Nerves, especially the small ones
 in a living or  recently dead animal, they are observed
 to have numerous White Lines placed transversely, or
 in a serpentine direction.—Obs. onNerv. Syst. Tab. XIII.
   When the Nerves are moderately stretched, this ap-
 pearance becomes less evident; and when extended con-
 siderably, or when macerated in water, it vanishes en-
 tirely.
   Prockasca (De Came Masculiar) supposes these Ser-
 pentine Lines to be  owing to a decussation of Vessels
 aud Fibres of Cellular Substance straitening the Nerves.
   Dr. Monro considers them as Folds or Joints, allowing
 the Nerves to accommodate themselves to the various
 states of Flexion and Extention.
   The Nerves are supplied with Arteries from the neigh-
 bouring Blood-vessel, to which they  send  correspon-
 ding Veins.
   These, however, are small, and difficult of injection,
 excepting in  the large  Nerves, where the  Vessels are
 more considerable, and where,  after a minute injection
 the Nerve receives the colour ofthe matter  injected.
  Upon dividing the  Nerves, they are not found to pos-
 sess much contractility ; while the Arteries, upon being
 cut are observed to retract very considerably.
  They are generally lodged in  the common Cellular
 Substance and Fat, and in the Interstices ofthe  Visce-
ra and Muscles, where they  are prevented from being
compressed ; though in several parts they are exposed
to the hardness of Bones, or to the action of Muscles,
over or through which they pass.
  In their course through the different parts ofthe Bo-
dy, they generally run as straight as is consistent with 
27y
 the nature of the particular part over which they pass,
 and their own safety.
   In their progress, they divide into Branches,  which
 become gradually smaller, and which, though taken col-
 lectively, are inferior in size to the Trunks from  which
 they issue.
   The Branches generally run off at acute angles ; but
 in seveial  places they have a retrograde direction.
   They have commonly  the same kind  of distribution
 in the opposite  sides ofthe same Subject, and vary lit-
 tle in this respect in different Subjects.
   In some parts ofthe Body, several Nerves unite to-
 gether, and form a Plexus or Net-work ; in others, they
 unite into a Common Trunk -, and  in many, by such an
 union, a hard knot, termed Ganglion, is formed.
  When the Plexuses, or the Common Trunks, are mi-
 nutely examined by slitting open their coverings, it is
 found, that their Fibrillx are intermixed in such a man-
 ner, that each of the Nerves passing out from the Plexns,
 or from  the Common Trunk, is composed of Fibrillx
 from several, or  from all  the Nerves which entered it,
 in consequence of which,  the Organs in general are fur-
 nished with Nerves from  various sources. Obs. on Nerv.
 Syst.
 " The Ganglia  differ from each other in size and Fig-
 ure.  Thev have thicker Coats  and are more Vascular
 than the Nerves; and are larger than the whole ofthe
 Nerves,  taken conjunctly, which enter into or go out
 from them.—They are supposed to serve as fresh sour-
 ces of Nervous  Influence.
  They  are composed of Nervous Fibrillx, covered "by
something  like a Cineritions Matter, and are so divided,
multiplied, and  intermixed, that each of the Nerves,
passing  out from a Ganglion is found to  be composed
of Fibrillx  derived from the greater part ofthe Nenes
which enter it. — Obs. on Nerv Syst.
  Where Nerves pass out from the side of a Ganglion,
thev ai e composed of Fibrillx which come off in contrary
directions;—the one set  from the beginning,  the  other
from the opposite extremity ofthe Ganglion.
  The Nencs which go out from the different G:mgli4
Lav* the Jann. structure with those  which enter thtm,
(>_ 4 
                       280                        i
but are found, with only a few exceptions, to be rather
larger.
  In the Trunk of a Nerve, the Chords appear to run
parallel to each other ; but when macerated in water,
so as to dissolve the Cellular Substance, or when other.
wise accurately examined, they are seen evidently to
intermix  somewhat after the manner of the Fibrillx in
the Plexus, or in the Ganglia—Obs. on Nerv. Syst.     **
  The Termination of the Nerves is soft, pulpy, and pel-
lucid, as  is distinctly seen in the Ratina of the Eve or
Ear;  the  external Covering being entirely  laid aside,
while the  Pia Mater, in particular, accompanies them
throughout-
  The Nerves preserve the motion ofthe Muscular Fi-
bres.
  They constitute the immediate Organs of Sensation,
and convey Impressions made upon them to the Mind.
  The manner in which these Impressions are prodnced,
—whether by a Vibration communicated to the Nerves;
or by a Liquid called Nervous Fluid, contained and mo-
ving in them ;—or by an electric Matter common to them
and many other substances; or in what manner that
power acts, termed  Animal Electricity, which has been
lately discovered to  take place in the Animal Kingdom,  /
upon the application of certain Metals ; is  not yet un-
derstood.
 DISTRIBUTION OF THE NERVES.

  The Nerves are distinguished into two Classes; one •
arising from the Brain, termed Cerebral; the other from
the Spinal Marrow, termed Spinal Nerves.
  The Cerebral Nerves are generally reckoned Nine or
T,-i Pairs in number, beside a particular Pair which has,
the name of Sympathetic.
  Tiiey pass through the Holes in the Base ofthe Cra-
nium, and receive  their respecthe names according to
their order ; or from their Functions ; or from the parts
on which they are  dispersed, ckc.
  The Spinal Nerves  consist of Tvser.ty-nine or Thirty
lairs, which pass out  between the  different Vcrtcb:■-*., 
281
 besides a Pair culled Accessory, which enter the Crani-
um from the top ofthe Spinal Marrow, and afterwards
pass out with one of the Cerebral Nerves.

  Nerves which pass through tin Base ofthe Cranium-
  The First Pair, or Olfactory Nerves,—arise, on each
«de ofthe Brain,liy three separate Strix, from the Cor-
pora Striata, at! the under and back-part of the Anteri-
or Lobes, near where the Carotid Arteries enter the Fis-
sures oj Sylvius.
  They arc more tender than the other Nerves, and al-
so differ from them in not being composed of Fasciculi.
  They run each in a furrow, u|*on the under Surface of
the  Anterior Lobe* of the Brain, converging a little and
becoming somewhat larger,  till they reach the Cribri-
form Plate ofthe OEthmoid  Bone.
  Upon this Plate, each forms an Oblong Bulb, which, in
colour, and consistence,  resembles the Cortical part of
the Brain, but  is mixed with streaks of Medullary Mat-
ter.
  From this Bulb, numerous  Nervous Filaments are
sent off, which pass through the Holes ofthe Cribriform
Plate,  and now become  firm and strong like the othtr
Nerves, by receiving a covering from the Dura Mater.
  After entering the Nose, they divide  into two Por-
tions or Planes,—one passing on the Septum, the other
upon the Ossa Turbinata, and other parts opposite to
the Septum, and both running at first in Grooves of the
Bones.
  They form a beautiful  Plexus, which is spread out up-
on that side of the Membrane of the Nose winch is con-
tiguous to the Bones, and may be traced a considerable
Way upon it in distinct Threads, which becoming  grad-
ually smaller, sink into the Membrane, and are suppo-
sed to  terminate on the surface next the Cavity of the
Nose, there constituting the  Organ of Smell.
  The Second Pair, or  Optic Nerves,—which are of great
size, arise from the Thalami Optici, and are  connected
in tlieir passage  to Tubercles at  the root of  the lufuii-
dibulem, which furnish them with an addition of Medul-
lar! Subs'tance.
  They are of a  purer white  than other Nerves, having
less Cincriuous Matter entering their composition, atftl 
282
differ also in the Pia Mater furnishing to them with a J
general Covering, before it invests the several Fasciculi  j
of which they are formed.                            1
  At the fore-part of the Sella Turcica, they unite, and
have their Medullary Parts intimately intermixed.      '
  From the union, they go obliquely outwards and for-
wards  through the  Foramina Optica into the Orbits^  j
and advancing in the Orbits in a waving direction,—to  I
prevent them from being over-stretched in the motions J
ofthe  Eye,—they perforate the  Balls, to be expanded  I
into the Retinx, which have been already described.   I
  The Third Pair, or Motores Oculorum,—smaller than
the Optic Nerves,— arise at the under, inner, and back-
part ofthe Crura Cerebri, or between the Corpora Al-
bicantia and Tuber Annulare, by numerous Threads
which  are soon collected into their respective Trunks.
  They pass outwards, perforate the Dura Mater  at the
sides of the  Posterior Clinoid  Process, and running a«
long the upper part of the Cavernous Sinus, at the out-
side of the Carotid Arteries, they get through the Fo-
ramina Lacera into the Orbits.
  Upon entering  the  Orbits, they divide into several
Branches, which supply the greater number of the Mus-
cles  of the  Eye,  in consequence of which the Nerves
have obtained their particular name.
  A Branch runs to each ofthe Muscles within the Or-
bit, excepting the Trochlearis and Abductor, and the
Nerve likewise assists in forming a small Ganglion, ter-
med Ophthalmic,  from which Twigs are sent off to sup*  '
ply the Ball ofthe Eye.
  The Fourth Pair, or Pathetic,—have their origin the
highest ofthe Cerebral Nerves, and are the most slen-
der of the Body, being generally formed of one Fascicu-
lus only on each side.
  They arise by a single, and sometimes by a double
root, behind the Testes, from the Medullary Expansion
which lies over the passage ofthe Fourth Ventricle, and
which unites the  Processus and Testes to each other.
  They afterwards turn round the Crura Ceribri, and
perforate the Dura  Mater atthe edge of the Tentorium
some way behind the entrance of the Third Pair.
  They run afterwards along the Cavernous Sinuses, at
the outer side ofthe Third Pair, then cross over the Pair» 
283
 and passing out ofthe Cranium through  the Foramina
 Lacera, they go obliquely over the Muscles at  the up-
 per part ofthe Orbits, to be entirely dispersed upon the
 Pathetic or Trochlearis Muscles.
  The Fifth Pair,  or Par Trigeminum,—which  are the
 largest Nerves of the Brain,  arise, each by an anterior
 small, and a posterior large Portion, from the  side of
 the Tuber Annulare, where the Crura Gerebelli join it.
  They enter the Dura Mater a little below the Tento-
 rium, over the points ofthe Partes Petrosx of the Tem-
 poral Bones, and form a Plexus on each side, in which
 upwards of fifty Fasciculi have frequently been enume-
 rated.
  The Plexus sinks close by the outside of the  Caver-
 nous Sinus, concealed  by a doubling ofthe Dura Mater
 and forms  a Ganglion sometimes called Gasserion after
 Gasser, who, if not the Discoverer, was the first  who il-
 lustrated it.
  The Ganglion is of a semilunar form, and placed trans-
 versely with respect to the Trunk  of the Nerves.
  From the opposite and curved edge of the Ganglion,
 three large Branches come out: the first and Anterior,
 termed Ophthalmic,—the second and Middle, the Supe-
 rior Maxillary, and the third and Posterior, the Inferior
 Maxillary.
  The First Branch ofthe Fifth Pair,—sX the side ofthe
 Sella Turcica, is situated lower than the Third Pair, and
 afterwards crosses over it, being previously connected
 by nervous Matter to the Trunk ofthe Fourth Pair.
  It goes through the Foramen Locerum into the  Orbit,
 and there dividesis into the following Branches, viz.
  The Supra-Orbitar, which is the  largest of the  whole,
being a continuation ofthe Ophthalmic.
  It passes immediately under the Membrane  which
lines the upper part of the Orbit, and splits into two
branches of unequal size,
  The smaller Branch termed Supratrochlear is, runs un.
rler the Superciliary  Ridge to the Upper Eye-lid and
Forehead.
  The larger passes through the Foramen Supra-Orbi-
tarium,__or over the Superciliary  Ridge when the Fo-
ramen is a wanting,—sends Branches to the Upper Eye-
lid, aud divides into several others, which run back partly 
                        284                        *
 above, chiefly under the Frontal Muscle, to supply the ,
 fore and upper part of the head in general, while mi-  '
 nute Fibres appear-to penetrate the Bones.*
   The Nasal Branch, which  runs obliquely over the
 Optic Nerve, where  it detaches a Filament or two to  !
 the Eye, then under the Levator Muscles ofthe Eye-lid
 and Eye ;  and getting between the Abductor Oculi and
 Trochlearis, passes to the inside ofthe Orbit.
   It sends a Branch, which after entering  the Foramen
 Orbitarium Internum Anterius, re-enters  the  cavity of
 the Cranium, and gets upon the Cribriform Plate ofthe
 OF.thmoid Bone.
   From thence it passes down through one ofthe ante-
 rior Holes of this Plate, and  sends Twigs  to the mem-
 brane  at  the  anterior part  of the Nostril, while the
 Nerve descending at the fore-part ofthe Septum Nari-
 urn,  is  dispersed  upon the point, and  Wing of the
 Nose.
   The continuation of the Nasal Branch, now called In-
 fratrochlearis, passes forwards to the inner Corner ofthe
 Eye, and  is distributed upon  the Lacrymal  Sac and
 parts adjacent.
   The  Lacrymal Branch, which runs along the Abduc-
 tor Oculi Muscle, sends Twigs to the Membranes and ■
 Fat near  it, likewise one or two through the substance
 of the Cheek-bone,  and one  in particular to  the Sub-
  stance ofthe  Lacrymal Gland, while  another passes o-
 ver the Gland, and vanishes in th« neighbouring parts.
    A Branch to the Ophthalmic Ganglion, which is some-
 times sent off from  the  Nasal, at otlier times  from the i
 Ophthalmic Trunk.                                *
   The  Ophthalmic Ganglion,—termed  also Lenticular,
 from its shape, is formed by this Branch from the Fifth
 and by another from the Third  Pair, and is commonly
 the smallest in the Body.
   It is of an oblong  form and compressed, is situated at
 the outside ofthe Optic Nerve a little before its entrance
 into the Orbit,  and is concealed  in Fat.   Sometimes,
 though rarely, the Filaments which form it take theiin
 origin entirely from  the Third Pair.
   From the Ganglion, about a dozen of Filaments arise,
 termed Ciliary  Nerves,  collected  into two  Portions,
t which creep  along  the opposite  sides of the  Optic i 
285
 Nerve, separated a little from each other and running
 in company w ith the Ciliary Arteries.
   Besides  the Ciliary  Nerves from the Ganglion, one
 and sometimes  two Filaments  arise  from the Ramus
 Nasalis,  and pass along with the other Ciliary Bran-
 ches.
   The Ciliary Nerves, running with  scarcely any divi-
 sion, reach the back-part of the Eye ; and a little be-
 fore the Insertion ofthe Optic Nerve, enter the Sclero-
 tic Coat, pass obliquely through  it, and about the mid-
 dle of the Ball, appear upon the  Surface of the Tunica
 Choroides.
  Upon this Coat, they run  flat, and in a parallel direc-
 tion, sending very few  evident Branches, either to it or
 to each other, till they  reach the Ciliary Circle, where
 they divide into numerous minute Filaments.
  Upon the Choroides,  five  or six are larger than the
 rest, some being so minute as almost to escape the nak-
 ed Eye
   At the Ciliary Circle, each commonly divides into two
 Branches, which are covered by the Cellular Substance
 ofthe Circle : and these, at the root ofthe Iris, are sub-
 divided into still smaller Branches, which run in a radi-
 ated and waving direction,  the Ciliary Vessels being
 interposed.
  Near the inner edge of the  Pupil, they are united in-
 to Arches, from which very  minute Twigs run to the
 interior margin of the Iris,
  The Second Branch,  or Superior Maxillary  Nerve is
 larger than the Ophthalmic,  and is principally dispersed
 upon the  Parts belonging to the Upper Jaw, from which
 it has its name.
  It goes through the Foramen Rotundum ofthe Sphe-
 noid Bone,  and at its exit divides into numerous Bran-
ches, viz.
  The Spheno-Palatine, or Lateral Nasal Nerve, which
sends a reflected Branch through the Foramen  Ptery-
goideum  of the  Sphenoid Bone, to Join the Sympathe-
tic Nerve in the Canalis Caroticus, and a Branch which
enters the Foramen lnnominatum of the  Pars Petrosa,
to join the Portio Dura ofthe Seventh  Pair.
  The Lateral  Nasal Nerve goes afterwards into the
 Sphenopalatine  Hole, to be dispersed upon the under 
286
and back-part of the Septum, and opposite side  ofthe
Nose, and upon the Membrane ofthe Sphenoidal Sinus
and Eustachian Tube :—One Branch in particular, after
passing along the Septum, goes through the Foramen
Incisivum to the roof of the Mouth.
  The Potato Maxillary, or Palatine Branch, which de-
scends through the Canal leading to the Foramen Pal».
tinum Posterius ; and running near the Alveoli with cor-
responding Blood-Vessels, sends Branches to the Velum
Palati and Roof of  the Mouth, and Minute Filamentsi
which penetrate into the Palate-place of the Superior
Maxillary Bone.
  Small  Branches, which pass round the Upper Jaw,
and vanish in the Cheek.
  A Twig, which goes through the Hole in the Os Ma.
lx, along with a Branch of the Ocular Artery, to the
Face.
  Small Filaments, which runs down into the back-part
of the Superior Maxillary Bone, and supply the sub-
stance of the Upper Jaw, the large Dentes Molares, and
Membrane lining the Antrum Maxillare.
  The Second Part of the Fifth Pair, after send'rag
off these  different Branches, goes  into the Canal under
the Orbit, and forms the Infra-orbitar Nerve, which,
while in the Canal, gives off Filaments passing through
minute Conduits in the Upper Jaw, to the Antrum, to;
the Substance ofthe Bone, to the  small Molares, Caru-
nus, Incisores,  and fore-teeth ; and sometimes a Twig*,
the companion of a small Branch ofthe Internal  Maxil-
lary Artery, to the Membrane lining the Orbit.
  The Infra-Orbitar Nerve passes afterwards out of the j
Foramen Infra-Orbitarium, and divides into many large
Branches, to be distributed upon the Cheek, Under-Eye-
lid, Upper Lip, and side ofthe Nose.
  The Third Branch, or Inferior Maxillary Nerve, gow
through the Foramen Ovale of the Sphenoid Bone, an!
supplies the parts belonging  to the Under Jaw, and tbe
Muscles situated between it  and the Os Hyoides, by
the following Branches, viz.
  One, or sometimes two Deep Temporal Branches,^
the inner part ofthe Temporal Muscle.             '
   Branches, to the Masseter,  Pterygoideus, and Bucci-
nator Muscles. 
287
   A Branch  which passes behind the Cervix of the
 Lower Jaw, and gives off Filaments to the Fore-part of
 the Ear, and afterwards accompanies the Temporal Ar-
 tery upon the side ofthe Head, where it terminates.
   A Branch, to the Buccinator Muscle and other parts
 ofthe Cheek.
   A Nerve of considerable size, termed Lingual or
 Gustatorius, which  passes between the Pterygoid Mus-
 cles, to the  inner of which it gives some Filaments.  It
 then sends  off, from  its under side, a Ganglion  which
 transmits Nerves to the Inferior Maxillary Gland.
   The Lingual Nerve also transmits several Branches
 to the Sublingual  Gland,  and to the Muscles ef the
 Tongue.
   It terminates, at length, near the Point of the Tongue
 by many Branches which belong chiefly to the Papillx;
 in consequence of which this Branch is considered as
 the principal Nerve of the Organ of Taste.
   The Trunk of the  Inferior Maxillary Nerve, having
 parted with the Lingual Nerve, directs its course be-
 tween the Pterygoid Muscles to the Posterior Foramen
 ofthe Inferior Maxillary Canal.
   Before entering the Canal, it sends off a  long  and
 slender Branch, which is lodged at first in a Furrow of
 the Bone, and goes afterwards to be  dispersed chiefly
 upon the Mylo-hyoideus Muscle and  Subligual Gland.
   The Trunk of the Nerve is afterwards conducted a-
 l6ng the Canal of the Jaw under the Alveoli, where it
 distributes Filaments  to the different Teeth of tbe cor-
' responding  side, and to the Substance ofthe Bone : and
.coming out  ofthe  Canal by the Anterior Maxillary Fo-
 ramen, somewhat diminished in size, it scatters its re»
 m'lining Branches upon the Chin and under Lip.
   The Sixth Pair, or  Abducentes, arise from the begin-
 ning of the  Medulla Oblongata,  at the part common to
 the Tuber Annulare and Corpora Pyramidalia, and are
 the smallest of the Cerebral Nerves, the Fourth Pair
 excepted.
   They perforate  the Dura Mater at  the inner side of
 the entrance ofthe Fifth Pair, and run forwards  within
 the Cells of the Cavernous Sinus ;  but  so surrounded
 by Cellular Substance, as to seem to be protected from
 the Blood of that  Receptacle. 
                        288
  While in the Sinus Cavernosi, they  are situated be- ,
tween the Opthalmic Nerves and Carotid Arteries, up-
on the surface of the latter of whicli they send off"two <
or three  Filaments on each side of the Head, to assist
in forming the Great Sympathetic Nerves.
  The Trunks of the Sixth Pair afterwards go through
the Foramina Lacrera, to be  dispersed entirely upon
the Abductor Muscles of the Eyes.
  The Seventh Pair is  composed, on  each side, of two
portions,—the Nervus Auditorius, Nervus  Acusticus, or
Portio Mollis ; and the Communicans  Faciei, or Portio ,
Dura.
  The Portio Mollis, is the softest of the Nerves, ex-
cepting the Olfactory.
  It arises by transverse Medullary Strix from the An-
terior part of the Fourth Ventricle,  and  is separated
from its fellow of the opposite side only by the Crena
ofthe Calamus Scriptorius.
  The Strix, turning round the Medulla Oblongata, ap-
ply themselves  to  tbe Tuber Annulare, from which
they receive an addition of substance, and then get to
the side ofthe Portio Dura.
  The Portio Dura, sometimes also called Sympatheti-
ca Minor, arises from that  part of the Brain which is
common to  the  Pons  Varolii, Crura  Cerebelli  and me
dulla Oblongata  ; and  at its origin, is situated upon the
inner side of the  Portio Mollis.
  Between the origin ofthe Portio Dura and Trunk of  \
the Portio Mollis, a  small  Nerve  arises, termed by
Wrisberg, Portio Media inter P. Duram et P. Mollem.
  It comes off by minute Fibrillx, which soon unite in-,
to a Trunk,  from the posterior part  of the Pons Var-
olii, or from the adjoining part ofthe Medulla Oblongs  i
ta, and is an Accessory Nerve ofthe Portio Dura-
  The Portio-Dura,  considerably smaller than the P.  '
Mollis, gets into the Meatus Auditorius Internus, and
is there lodged in a kind of half-sheath, formed by that
Nerve, to which  it is connected by fine Cellular Sub-
tance ; the Dura Mater, which lines the  Passage, giv-
ing here  a general Covering to both Nerves.
  Portio Mollis.—The  Portio  Mollis is formed pf two  <
Fasciculi, nearly of equal size, one of which belongs to 
                       289
the Cochlea, tbe othej to the Vestible and Semicircular
Canals.
  Each of these Fasciculi passes by numberless Fibril-
lx through the  Cribriform Plate in the bottom of the
Meatus  Auditorius Internus, to the  inner parts of the
Labyrinth.
  The Fibrillx destined for the Cochlea go through the
Holes in the sides of the Modiolus.
  Some  pass between the Plates which form the Septa
ofthe Gyri ; others go through Holes between the Os-
seous Plates of  the Lamina Spiralis ; but by much the
greatest number perforate the sides of the Modiolus,
between the Septum of the Gyri and the Lamina Spi-
ralis.
  The larger Fibrillx run upon the Membrane  covering
the Lamina Spiralis ; while the smaller go  from the
Modiolus, between the Osseous Septa and on the inner
sides of the Gyri, to be dispersed upon the Membrane
lining them.
   The remaining Fibrillx perforate the Plate common
to the Modiolus and Infundibulum, and vanish upon the
last half-turn of the Lamina Spiralis and the Cupola of
the Cochlea.
  Upon the Osseous part of the Lamina  Spiralis, tlie
Nerves  have the common appearance; but  upon the
Membranous Portion, they are of the colour of the Re-
tina ofthe Eye.
   In the whole  of their cour.se upon the Lamina Spira-
lis, they form a Real  Retina ; though the reticulated
structure becomes much less  apparent  upon the outer
part of  the Lamina, and upon the continuation of the
Membrane  lining the Gyri,—the Nerves seeming to
terminate in a  semipcllucid Pulpy Membrane resem-
bling the Retina of the Eye.
   The Membrane upon which the Nerves are expanded,
is but slightly connected to the Periosteum which lines
the inner side of the  Cochlea, and which, though thin,
may be readily perceived, being painted with Blood-
vessels ;—nor does it  differ from tlu: Periosteum lining
the Tyinpanuni.—See Dr. Monro's Treatise upon the
Ear-
   The Fasciculus which belongs to  the Vestible, and
Semicircular Canals, forms  at first a  Plexus., then  a
     VOL.  II.             H 
                           "290
     Gangriform Enlargement, previous to its entrance into
     the Labyrinth.
       The Nerves which belong to the Vestible and Semi-
     circular Canals  pass through the Macula Cribrosa, or
     holes subdivided  into  smaller Holes  by  Cribriform
     Plates in the  bottom of the Meatus Auditorius Inter.\
     nn6.
       Of these Branches, small Filaments pass through the
     Macula Cribrosa in  the Inferior Fossula ofthe Meatus
     Auditorius Internus,  to the AlveuS Communis or Sac-*
     cuius Vestibuli.
       A  small Branch  goes through  another Cribriform*
     Hole in the Inferior Fossula, to the Ampulla of the
     Posterior Membranaceous* Semicircular Canal.
       A Branch larger than any of the former, enters the
     Posterior Hole in the upper Fossula of the Meatus Irr-J
     ternus, to be  dispersed upon the Ampullx ofthe Supe"
     rior and Exterior Membranaceous Canals.            *
       The Nerves,  after reaching the  Sacculus Vestibuli
     and the different Ampullx,  are spreafl out upon them,
     as in the Cochlea, in the  form of a  Net-work, the Fi-
     bres of which,  by degrees becoming pellucid, disap-
     pear upon the beginning of the Membranaceous Canals.
       Portio Dura.—The Portio Dura separates  from the
     Portio Mollis, at the bottom ofthe Meatus Auditorius,
     Internus, and enters the Canalis or Aquxductus FallopU,
     bv the anterior Hole in the upper Fossula atthe bottom
     ofthe Meatus.
       After g-etting into the  Canal, it receives the retro-
     grade Nerve from the second Branch ofthe Fifth Pair,
     which enters by the  Foramen Innominatum on the for*.'
     side of the Pars Petrosa.
       It sends Twigs through the Foramina in  the  sides
     the Aqueduct, to the Mastoid Cells and to the Muscle o4j
     the Stapes.
       A little  before its exit from the  Aqueduct in the
     Adult, but at  the outer end  of it in  the  Foetus,  it gives,
     off a rtf! cted B-anch, termed Chorda Tympani, which
     j asses between the long Processes ofthe Malleus and
     I  <*us, and over the Membrana Tympani.
YMl   the Chorda Tympani, goes afterwards in  a Tissure at
l\f   the O'.itside of  the Eustachian Tube, and joins the Lin- 
291
  gual Brandt of the Fifth Pair, soon after that Ncrvf
  has got out ofthe Cranium.
    In its passage, it supplies the Muscles ofthe Malleus
  and the Membranes, &c ofthe Tympanum.
    The Portio Dura afterwards passes out of the Accp»er
  duct by the Foramen  St)lo-mastoideum, and is at li.st
  lodged deep, being situated in  a hollow behind  the Pa-
  rotid Gland.
    Here it gives a small Occipital Branch, which sends
  Twigs to the back-part ofthe Ear, and terminates in the
  Oblique Muscles ofthe Head-
    It sends a Branch  to  the Digastric, and another to
  the Stylo-hyoid Muscle ; gives off  a Filament  which
  joins the Auricular Branch of the  Inferior Maxillary
  Nerve, and goes to the fore-part of the Ear ; and is con-
  nected by another small  Filament at the under part of
  the Ear; with Branches ofthe Sympathetic Nerve whicli
  run along the External Carotid Artery.
    It also furnishes Filaments to the Carotid Gland, and
  then perforates jt, dividing into large Branches, which
  join, separate, and rejoin, different times, on the side
  ofthe Face.
    This  Plexus is expanded in  such a manner as to con-
  stitute what has been called by some the  Pes Ancerinus,
  and is divided into the following sets  of Branches, viz.
    The  Temporal Branches, which ascend upon the side
  ofthe Head, to be distributed upon the Temple ;  sorrre
  running over, others under the Branches ofthe Tempo-
  ral Artery, and forming several joiuings with the Fron-
  tal Branches of the first part ofthe Fifth Pair of Nerves :
    The  Superior Facial  Branches, which are dispersed
  upon the Orbicularis Oculi Muscle, and the parts in ge-
  neral about the outer angle ofthe Eye,  communicating
  in various places  above  and below the  Orbit, with the
  first and second Branches ofthe Fifth Pair.
    The Middle Facial Branch, or the Great Facial Nerve,
  which runs  across the  Masseter  Muscle, and  divides
'  into many Branches, to be dispersed upon the Cheek,
  and side ofthe Nose and Lips.
    They are  connected with the Branches of the Supe-
  rior Facial,  and near the coiner of the Mouth, with o-
  thers of the second and third parts of the' Fifth Psrirj 
                       292                        i
They have  likewise  some  communications with  the
deep Brunches  "of those two Nerves which pass out- |
wards between  the Masseter and Buccinator Muscles.  j
  The Inferior  Facial  Branches, which proceed along
the side of the under Jaw, to be dispersed upon  the
parts covering it, and upon the Under Lip ; and connect
themselves with some of the Middle Facial Branches,
and with others belonging to the third part of the Fifth '
Pair.                                               i
  The Descending,  or Subcutaneous Cervical Branches, 1
some of whicli run forwards  under the Lower Jaw,  and
others downwards, near the External Jugular Vein-, to
the Superficial  Muscles, and to the Integuments at the
side ofthe upper-part of the Neck,  where they form
communications with the Inferior Facial Branches,  and i
with diffeient Branches of the  Upper  Spinal Cervical
Nerves,
  The Eighth Pair arises from the Medulla Oblongata,
at the sides of  the Bases of the  Corpora Olivarra,  and
consist in  each side, of the Nervus  Glosao-pharyngetw,
and Pars Vaga.
  The Gtosso-Pkaryngeus is the smaller of the two, be-
ing oily a little superior in size to the  Nerves ofthe
Fourth Pair.
   The Pars  Vaga comes off immediately under the for-
mer, and is composed of several separated Fasciculi*')
whicli are soon collected into a single  Cord.'
  The two Nerves, passing- outwards, go through the ]
Base of tbe  Cranium, immediately before the end of
the Lateral Sinus, by the  Hole common to the Occipi- J
tal  and Temporal Bone, and are separated from eacho-
ther and from the Sinus by small Processes of the Dura
Mater.
  The Glosso-Pharyrrgeus, termed also Lingualis Latera- '
lis, upon its  exit from the  Cranium, sends a Branch ■
backwards, which joins the Digastric Branch of the Por-
tio  Dura.
  A little  lower, it  gives off Branches, which, with o- i
thers from the Pharyngeal Branch ofthe Eighth Pair,
and from the Great Sympathetic Nerve form a Plexus
which embraces the Inttrnal Carotid Artery, and after-
wards sends  Branches along the Carotis Communis to I
the Heart. 
293
  Still lower,  it gives Branches which communicate
with others belonging to the Pharyngeal Nerve, and go
to the upper part ofthe Pharynx and to the Stylo-Phar-
yngeus Muscle.
  The Glosso-Pharyngeus, after sending a Twig or two
to the Tonsil,  to the upper part of the Pharynx, and
Membrane of the Epiglottis, divides, into  many  Bran-
ches, which run partly to the margin, and partly to  the
middle of the root of the Tongue, supplying, especially
the Papillx Majores and the parts in their neighbour-
hood.
  The Pars Vaga,—upon emerging from the Cranium,
frequently becomes a little increased in diameter for a-
bout an  inch downwards ;  forming what some authors
have termed its Gangliform Enlargement.
  It descends in the Neck at the outer and back-part
of the common Carotid Artery,  to which it is closely
united, being included along with  it in  the same com-
mon sheath of Cellular Substance.
  At the upper part ofthe Neck, it transmits a Branch
to the Pharynx ; and immediately afterwards, a large
one to the Larynx ;  and near the top ofthe Thorax, it
sends a Filament, and sometimes two, to the Heart.
  The Pharyngeus—chiefly formed by the Pars Vaga, but
partly also by a Branch from the Accessorius,  is after-
wards joined by Branches from the Glosso-Pharyngeus,
and descends obliquely over the Internal Carotid Artery.
  Near  the origin of the Artery, it sends  Filaments
which join others from the upper  part of the Great Sym-
pathetic, and creep along the common Carotid, to be u-
nited with the  Carotid Artery.
  Upon  the middle of the  Pharynx, it  expands into a
Gangliform Plexus, from which many small Branches
are sent out, to be distributed upon the three Constric-
tors ofthe corresponding side of the Pharynx ; one or
two Filaments  uniting above with the Glosso-Pharyn-
geus, and others below with the  Laryngeus Superior.
  Tlie  Laryngeus  Superior,—descends  obliquely  for-
wards between the Carotid Arteries and Pharynx ;  and
behind the origin of the Carotids, is divided into a large
Internal or Superior, and a small  External  or Inferior
Branch.
  The Internal Branch passes forwards between the Os
                       H  2 
                       294                       I
Hyoides and Superior Cornu of the Thyroid Cartilage. I
  It divides.into numerous Branches, some of which go I
to the Arytenoid Gland, and to the Oblique and Trans-1
verse  Arytenoid Muscles, and others to the Glandular I
Membrane ofthe Epiglottis ; while the greater number I
and the largest of these Branches are dispersed upon I
the Glandular Membrane lining the upper portion of 1
the Larynx and parts adjacent.                      1
  The External Branch,—which  Scarpa considers as 1
more properly termed Pkaryngo Laryngeus,—is originally I
Composed of a Branch from the Internal Laryngeal, ami
another from the Great Sympathetic ;  and is connected
by a  Filament to the Pharyngeal, and sometimes aho
by one to the Internal Laryngeal Nerve,
  1% imparts Twigs to the Middle and  Lower Constric.
tors of the Pharynx,  and afterwards terminates in the
Thyroid Gland and inner part ofthe Larynx.
  The Filament, sent from the Pars Vaga at the bot-
tom ofthe Neck, joins the Great Cardiac Branch of the
Sympathetic Nerve in the upper part of the Thorax, to
be dispersed upon the HearJ.
  The Ninth Pair,—frequently termed Linguales, and
sometimes Linguales Medii,—arise from the under and
lateral parts of the Corpora  Pyramidalia, on the fore-  ■
side of the Medulla Oblongata, by numerous Filaments '!
which are collected  into Fasciculi.
  They pass out at  the Superior Condyloid Foramina  *
of the Occipital Bone, after which they adhere, for some
way,  to the Eighth Pair, by Cellular Substance.
  A little below the Cranium, each of the  Trunks of
this Pair of Nerves is conjoined by across Branch  with
the Sub-occipital  Nerve, or with an  Arch which con-
nects  that Nerve and the First Cervical together.
  The Trunk  then descends between the Internal Ju-
gular  Vein and  Internal Carotid Artery, and at the root
of the Occipital Artery crosses over both Carotids to its
place of destination.
  Where  it'begins to cross over  the Carotids, it sends
down  a Branch  of considerable size, termed Descendens \
Noni.
  The Descendens Noni passes down a  certain length a-
long with  the  Common  Carotid Artery, and  in its
course, furnishes Branches  to the  upper ends  of the 
                        295
Omo-hyoid and Sterno-thyroid  Muscles, after whicli it
unites with Branches from the first and second, and with
small Filaments from the second and  third  Cervical
Nerves, forming an  Arch, from which long and slender
twigs go to the under portions ofthe Sterno-thyroid, and
to the Omo-hyoid a.*nd Sterno-hyoid Muscles.
  The Ninth Pair passes  afterwards  behind tlie Facial
Trunk and Temporal Veins, or the Trunk formed by
these, and over the root of the Facial Artery,—sending a
Nervous Twig to the Hyo-thyroid Muscle.
  Upon the Hyo glossus Muscle, the Trunk ofthe Nerve
is spread into a great number of Branches which go to
the middle ofthe Tongue, and terminate chiefly into its
Fleshy parts ; a Twig extending as  far as  the Genio-
hyoid Muscle, and two or sometimes only one Filament
anastomosing with the Lingual Branch ofthe Fifth Pair.
  Tlie Great Sympathetic Nerve,—obtaining its name
from its  numerous connections  with most of the other
Nerves of the Body,—is either formed originally by the
reflected Branch from the second and Fifth Pair, and by
one or two and sometimes three small  Filaments, sent
down from the Sixth Pair while in the Cavern his Sinus -,
or, according to tlie opinion  of some  Authors, the Sym-
pathetic sends off these small Nerves to join the Fifth and
Sixth Pairs.
  Upon  the Surface of  the Internal Carotid  Artery,
while in the Carotic Canal, the Branches  ofthe Fifth and
Sixth Pairs and Great Sympathetic, making this connec-
tion, are pulpy and tender, and form a Plexus which su**.
rounds the Carotid, and from  which the Trunk of the
Sympathetic is  most frequently considered as being sent
out.
   After  escaping from the  Carotic  Canal, the Trunk,
which is of small size, is closely connected  for a short
space, with the Trunks ofthe Eighth and Ninth Pairs ;
and, separating from these, it expands into a large Gang-
lion,—termed Ganglion Curvicale  Svperius,—of a  long
oval form,  and situated opposite to the second Cervi-
cal Vertebra.
   From  this Ganglion, the Nerve comes out  very little
increased in size,—and descends on the  anterior Verte-
bral Muscles of the Neck,—behind the Eighth Pair of
R  3 
                         296                         ■
 Nerves, with which, and with the  Carotid  Artery, it is  |l
 connected by a Sheath of Cellular Substance.            1
   At the under  part of the Neck,  nearly where the In-  ■
 ferior Laryngeal Artery turns over towards the Larynx,  I
 the Sympathetic forms another Ganglion,  termed by  M
 some authors Cervicale Medium and by the others Cervi-  ■
 cale Inferius.                                         ■
   The Ganglion  Medium is somewhat similar in shape  ■
 and size to  the   Ganglion  Superius ; though  it varies  M
 considerably in these respects in different Subjects.      1
   From this Ganglion, principal Branches are sent down,
 one of which,  larger than the rest, and considered as
 the continuation of the Trunk, turns  outwards between
 the Inferior Laryngeal and Vertebral Arteries to another  j
 Ganglion.
   This Third Ganglion,—is placed at the  head of the
 first Rib, and is  termed by some Authors Ganglion Cer-  J
 vicale Inferius, or Imum, while others consider it as the  >
 first ofthe Thoracic Ganglia.
   The Cervical part of the Great Sympathetic is connec-  .1
 ted with other  Nerves, and dispersed upon different m
 parts by the following Branches, viz.                    V
   One or two short, but thick Branches, which connect  m
 the beginning of the Superior Ganglion with the root of  1
 the Suboccipital  Nerve ;                               |
   One or two Pulpy Nerves, which run forwards behind  I
 the Internal Carotid Artery, ajtd divides into many odvifl
 ers.  These, together with  Filaments from  the Glosso-]^
 pharyngeus,  form a Plexus which sends Branches to the  !
 tiangliform  Expansion ofthe Pharyngeus, and afterwards  1
 embraces the External Carotid Artery, sending Plexuses  j
 of Filaments along its different Branches  :               ]
  One or two other soft Nerves, going behind the Inter-
 nal Carotid, and with a Branch of the Laryngeus Inter-
 nus of the Eighth Pair, forming the Laryngeus Exter-  .,
 nus :
  Thick short Roots connecting the First, or Conjuga-  i
 tion ofthe First and Second Cervicals, with the superior
 Ganglion ofthe Sympathetic Nerve.
  From  the  Superior Ganglion also, are sent off small
Branches, whicli uniting with Filaments from the Laryn-
geus Superior, form the  Ramus Cardiucus Sxpremus, qc
 Superficialis Cordis- 
297
      The Superficial Cardiac Nerve of the Sympathetic, in
    the Right Side, divides into two Branches at the bottom
    ofthe Neck, Which send a Filament or two along the In-
    ferior Laryngeal Artery to the Thyroid Gland and after-
    wards unite with  the  Superficial  Cardie Nerve of the
    Eighth Pair before the Subclavian  Artery, and with the
    Laryngeal Nerve behind  it.—In the  left side, it termi-
1    nates in the Cardiac Plexus of Nerves.
      From the Second, Third, and Fourth  Cervical Nervesi
    an equal number of Cords descend behind the Scaleni
    and Rectus  Major  Muscle, to the  middle  Ganglion of
    the Great Sjinpathetic.
      From the opposite side of the Ganglion, Branches are
    sent down, which join and form the Nervous  Magnus
    Prrfundus j others  are  fixed to the Superficial Cardiac
    and to the Recurrent of the Eighth Pair;—the rest go
    partly over and partly  behind tlie Subclavian Artery, to
    the Inferior Cervical, and to the first Thoracic Ganglion.
      Nervi  Acccssorii ad Par Octavum.—The  accessory
    Nerves arise by small Filaments from the lateral  Parts
    ofthe Medulla Oblongata and upper portion of the Spi-
    nal Marrow.
      The  Filaments  fro.n the Spinal M.arrow come, off'be-
    tween the anterior and posterior Bundles of the Cervical
    Nerves,—the first of them frequently extending as far as
    the space between the Sixth and Seventh Pairs.
      The different Filaments unite by  degrees into their re-
    spective Trunks, and often have connections whije within
    the Dura Mater, with one  or two Bundles of the upper-
    most Spinal Nerves.
      The Trunk ofthe Nerve passes out on each side ofthe
    Cranium, in company with the Nerve ofthe eighth Pair;
    but Forms no part  of that Nerve,  being included in its
    Own peculiar Sheath received from  the Dura Mater.
      After perforating the Cranium,  it separates from the
    Eighth, and descends  obliquely  outwards through the
    Sterno-mastoid Muscle to the Shoulder.
      At its exit, it sends off a Branch, termed by some Ra-
    mus Minor, (the Trunk itself being then called Ramus
    Major), which assists informing the Pharyngeal Nerve ;
    and  gives another,  smaller than the  former, to be connec-
    N-d to the Pars Vaga ofthe Eighth Pair.
      At the lore-part of the  Sterno-mastoid Muscle,  it is



-_________ 
                        298                          \
joined by an Arch to the Suboccipital, and frequently by
another to the First Cervical Nerve.
  In its passage through the Stemo-mastoideus, it sends
several Branches to the substance of that Mu&cle, and
terminates at length in the Trapezius. 
SPINAL  MARROW,
AND ORIGIN OF THE SPINAL NERVES,
   THE Spinal Marrow is the continuation of the Me-
 dulla Oblongata, and obtains its name Yn*m  being con-
 tained in the Osseous Canal ofthe Spine.
   It is invested by the same Membranes which cover the
 Brain, and has an  additional partial Involucjum  from
 the Ligamentous Membrane which lines the Bodies of
 the Vertebrx,  and which has been already taken notice
 of in the description ofthe Ligaments.
   On the inner side of the Ligamentous Lining, the Du-
 ra Mater is situated, whicli passes out ofthe Cranium
 by the Foramen Magnum Occipitis, and forms a Cylin-
 drical sheath whicli loosely envelopes the Spinal Mar-
 row, and extends as far as the Os Sacrum.
   It is more elastic than the Dura Mater ofthe Brain,
 and thereby admits more readily ofthe different motions
 ofthe Spine.
   At its egress from the Cranium, it is intimately con-
 nected to the beginning of the above mentioned com-
 mon Ligamentous Lining,  and is also united with the
 Pericranium at the edge of the Foramen  Magnum of
 the Occipital Bone.
  Below the First Vertebra of the Neck this intimate
 connection between the DuraMater and inner Ligament
 ofthe Vertebra is discontinued ; a. Cellular Fatty,  and
 Slimy  Substance, which surrounds the Dura  Mater
 throughout the rest of the  Canal, being interposed be-
tween the Membrane and the Ligament.
  The Dura Mater  is only in contact with the Tunica
 Arachnoidea, and this only in contact with the Pia Ma-
ter, and lying so loosely over it as to be separated from
 it with facility through the whole length ofthe Spine.
  The Spinal Marrow, like tlie Brain, consists of a cor-
tical and Medullary Substance, but differs in thii i-a- 
                        300

pect, that the Cineritious  Matter is placed withif* the
other.
  Upon the Surface of the Spinal Marrow, while lying
in its natural situation, many transverse Wrinkles or
Folds are observed,  which allow it to be extended in
the motion ofthe Vertebrx.
  It is a little  flattened on its  anterior and posterior
Surfaces, and is larger near tiie under part of the Neck,
and at the top ofthe Loins, where the  great Nerves of
the Extremities are sent off,  than in the other parts of   I
the Spine.
   It is divided  into two lateral Portions or Cords, which
are separated from each other externally by an anteri-
or and posterior Fissure  continued from the  Medulla
Oblongata ; and each ofthe lateral Portions is in some
measure subdivided by a superficial  Furrow into a lar-
ger anterior and small posterior Cord.
  The lateral  Portions are firmly united together by
fine Cellular Substance, but may be separated from each
Other before as well  as behind,—without lacerating ei-  \
ther,—to near  their middle,  where they are connected
by a Layer of Cineritious Matter which passed from the
one Cord into the other.
   When the Medulla Spinalis is divided transversely,   '
the Cineritious Substance is observed to have a Cruci-
form appearance, corresponding  with the Chords of
which it is composed.
   The Body of the  Spinal Marrow  descends as far as
the Second Vertebra of the Lions, and terminates there
by a Conical point, which is concealed by Fasciculi of
Nerves.
   Each  of the lateral portions  of the Spinal Marrow
sends off from  its anterior and posterior part-., flat  Fas-
ciculi of Nervous Filaments, which are placed opposite
tlieir fellows on the other side.
   Several ofthe Fasciculi of the Cervical Nerves detach  *
Filaments to those immediately abme  or below them;
and the  same thing is occasionally observed of some of I
the Bundles of Dorsal Nerves.
   The anterior and posterior Fasciculi perforate the '
Dura Mater, from the inner part of which each Fasci- i
cuius is  furnished with a. propc: Sheath, an 1 isionti- 
                          301
   nued within it, tbe Sheaths connected by Cellular Sub-
   stance only, till they get between the Vertebrx.
     Between the anterior and posterior Fasciculi or Spi-
   nal Nerves, and between  the Tunica Arachnoidea and
   Pia Mater, a small  Ligamentous Cord termed  Liga-
   mentum Denticulatum, is situated, which is attached to
   the Dura Mater, were that Membrane comes out from
   the Cranium and accompanies the Spinal Marrow to its
   inferior extremity.
     It adheres by Cellular Substance to the Pia Mater,
   and sends off from its opposite side small Chords, in the
   form of Denticuli, which carry the Tunica Arachnoidea
   along with them, and running more or less in atranverse
   direction, are fixed, each by minute Fibres to the Du-
   ra Mater, in the Interstices ofthe Fasciculi.
    The Ligamentum Denticulatum of the opposite sides
   incorporate with the Pia Mater at the Inferiorextremity,
   or Conical point ofthe Spinal Marrow, and form a Lig-
   amentous Filament which  perforates the under end of
   the Dura Mater, and is fixed by small  Fibres to the
   Membranes covering the Os Coccygis, in the manner
   the Denticuli are fixed to the Dura Mater.
    It was termed by some Authors Ligamentum Pia Ma-
   tris  It was considered by  the Antients as the Fortieth
   Pair of Nerves,  and was also ca\led Nervus Imparus Sa»
   crus.
    It assists in preventing the Spinal Marrow and the o,
   rigin ofthe Nerves from being overstretched.
    Having got between the Vertebrx, each of the pos-
  terior Bundles forms  a Ganglion, from the opposite end
  of which  a Nerve comes out,  and is immediately joined
5  by the anterior Bundle, thus  constituting trfe beginning
  ofthe Trunks ofthe  Spinal Nerves'.
    The Nervous Cords sent out from the Spinal Marrow
  after receiving  their  coverings from the  Dura Mater,
  becomes  considerably larger than the Fasciculi  whicli
  form them ;  as  has been already observed in the gen-
  eral description of the Nerves.
    As soon as the Spinal Nerves emerge  from between
  the Vertebrx, each  sends Branches backwards to the
  Muscles  near the Spine, andotlu-rs forwards to join the
  Great Sympathetic Nerve, while tlie Trunk is c-or.tinu*
  ed outwards to  its pluci* of destination- 
                        302
  The Spinal Nerves are distinguished on each side, by
numbers, according to the Bones under which they pass:
Thirty Pairs are most commonly enumerated.—One go.
ing under the Head, and termed Suboccipitals—Seven; ^
passing under the Vertebrxof the Neck ;—Twelve un.
derthe Dorsal;—Five under the  Lumbar Vertebrx;  i
and—Five under the pieces which originally composed"
the Os Sacrum.
  The Fasciculi which form the Cervical Nerves are
short, running nearly in a straight direction from their
origin to the Intervertebral Holes.  Those which form
the Dorsal Nerves are longer than the former, and run
more obliquely downwards, and those which form the
Lumbar and Sacral Nerves are very long and run still
more obliquely downwards, till at length the undermost
of them become nearly longitudinal.
  The size ofthe Fasciculi corresponds with that ofthe
Nerves which they go to form.—The  Fasciculi of the
four lowestCerv ical and first Dorsal.are large and broafy  ^
giving origin to the Great Nerves which supply the Su-
perior Extremity.—Those of the Back are much more
slender, while the Fasciculi ofthe Loins and the two up-   i
per Sacral ones are of great size, to form the very large   |
Nerves which run to the Lower Extremity.           ■
   The Lumbar and Sacral Fasciculi, while  included':
in the Dura Mater, form a Bundle of Cords, termed ;
Cauda Equina, from the resemblance it has to the Tail
of a horse ; especially when the Fibrillx of the Nerves  ]
are  unravelled by separating them from each other.
   The Fasciculi perforate the Dura Mater, nearly op-  j
posite to the parts where they pass through the Verte-  ',
brx,—of coarse the Nerves ofthe inferior parts ofthe .
Spinal Marrow emerge  from  the  Spine, considerably
lower than their different origins.
   Blood-vessels ofthe Spinal Marrov).—The Arteries of
the  Spinal Marrow consist of Anterior and Posterior  '■
Sp *al Arteries, and of many additional Branches com-
municating with others from the adjacent Vessels.
   The Anterior Spinal Arteries arise, one on each side ;
from the Vertebrals, near where these join to form the
Basilar Artery.                                      ,
   Upon the beginning ofthe Spinal Marrow, they gen-
erally unite into a common  Trunk, w hich descends in
that depression on the Anterior Surface  of the Medul; 
                       doj
la,  whereby it is distinguished into two Lateral Por-
tions,—and tlie Artery continues nearly ofthe same size
throughout, in consequence of additions it receives from
the neighbouring Arteries.
  In the Neck,  it communicates with the Vertebral
Thyroid, and  Cervical Arteries,  by Branches whicli
pass through the same Holes with the Nerves.
  In tlie Back, it receives Branches from the Intercos-
tal, and in the  Loins from the Lumbar Arteries; all of
which also go through the Intervertebral Holes.
  It terminates at the under end of the Spinal Marrow;
the Cauda Equina being supplied by Branches from the
Internal Iliac  Artery, whicli enter through the anterior
and posterior  Holes ofthe Os Sacrum.
  The Posterior Spinal Arteries,—arise commonly from
the inferior Arteries of the Cerebellum, and frequent-
ly from the Trunks ofthe Vertebral Arteries within the
Cranium.
  They are equal in length to the  former Artery, but
considerably inferior to it  in size, and continue separate
through the whole of their course.
  They have constantly a Serpentine appearance, and
form frequent  Inosculations with each other, and with
Arteries, the Branches of which communicate with the
Anterior Spinal Artery.
  The  Arteries of the Spinal Marrow are divided into
minute Branches, which  are dispersed upon  its sub-
stance, upon the Membranes which inclose it, and also
upon the substance of the Vertebrx and upon the ori-
gins of the Nerves.
  The  Fein* ofthe Spinal Marrow accompany their Ar-
teries,  and afterwards terminate in  the Sinus Venosi of
the Spine.
  The  Sinus Venosi consist of one on each  side, which
runs exterior to the Dura Mater, being chiefly lodged
in the Ligamentous Membrane which lines the fore and
lateral parts of the Vertebral Canal!
  They extend from the  Foramen Magnum of the Oc-
cipital Bone,  to the under end ofthe Os Sacrum, and
are so  irregular on their surface, and so much divided
and subdivided Within by the opening of Veins,  as in
many parts to have the appearance of Cells.
   Atthe different Vertebrx, they are conjoined by cross 
                       304
 Branches, which have a Semilunar form, like the Sur-
 face of the Bones which surround them.
   They communicate at their Superior Extremity with
 the Occipital and Lateral Sinuses, and send numberlesi
 Branches, outwards, which open  into the Veins the Ar- —
 teries of which anastomose with those ofthe Spinal Mar. '
 fow.

      Nerves of the Neck and Superior Extremity.

   Nervus  Accessorius.—The Accessory Nerve  belongs
 in some respects to this Class of Nerves;—but having
 part of its origin within the Head, and from its passing
 out with one ofthe Cerebral Nerves, it has been already
 described along with these.
   Suboccipital  Nerves.—These  were  formerly called
 Tenth Pair ofthe Head, and by many at present areter-
 med First ofthe Neck.
   They arise, on each side,  from the  beginning ofthe
 Spinal Marrow, by an Anterior and Posterior Fascicu-
 lus, like the rest ofthe Spinal Nerves ; and, like these
 also, they have  their Ganglia where they pass out be-
 tween the Bones.
   They perforate the Dura  Mater immediately under
 the entrance of the  Vertebral Arteries, and pass for-
 wards under them, and over the transverse Processes
 ofthe  Atlas.
   They afterwards appear in the fore-part of the Neck
 and are each connected above by an Arch to the root of.
 ofthe  Ninth Pair,  and helow by a  similar Arch to the
"First Cervical Nerve.
   Anteriorly, they are joined by one or two short Bran-
 ches to the  upper Ganglia of the Great Sympathetic
 Nerve.                                            ■
  They afterwards divide into Branches, which are dis-^
 tributed upon the Recti and obliqui Capitis, and upon
 some of the  deep E»tensor Muscles ofthe Head.
  The First Cervical Nerve,—comes out, on each side
between the Aflas and Second Vertebra of the Neck,
 and immediately splits into two parts ; the first of which
passes  forwards under the transverse Process of the At-
las, and is joined by  an Arch with the Nervus Acces-
sorius, and by Branches with the ninth Pair • It is also 
305
 connected by a soft Gangliform  pellucid root with the
 upper Ganglion of tlie  Sympathetic Nerve, sending a
 Branch downwards, to be fixed to the second Cervical
 Nerve, and also small Branches ofthe Muscles connec-
 ted with the fore-part ofthe Vertebrx.
  The other, whicli is the principal part goes backw ardsf
 and, after sending Branches  to the Extensor Muscles
 of the Head and Neck, perforates these, and forms the
 Proper Occipital Nerve.
  The Occipital Nerve ascends upon the Head with the
 Artery of that name, and terminates upon the Muscles
 and Integuments on the upper and back part of the Head;
 some of its Filaments anastomosing with others belong-
 ing to the first Branch of the Fifth, and Portio Dura of
 the Seventh  Pair.
  The Second Cervical Nerve,—after escaping from be-
 tween the Bones, gives off a Branch, which perforates
 the Muscles connected to  the fore  and lateral parts of
 the Vertebrx, and joins the middle Ganglion ofthe Sym-
 pathetic Nerve,
  It sends another Branch of considerable size down-
 wards  to the Trunk of the Third Pair.
  It sends several Branches to the Sterno-mastoid Mus-
 cle, behind which it is connected by an Arch, and still
 farther out by a Filament, with the Nervus Accessorius.
  It is afterwards divided  into several Branches, one of
 which passes downwards some way  upon the External
 Jugular Vein,  and, together with a Branch from the
 First Cervical, forms an Arch with the Descendens of
 the Ninth Pair.
  It gives off a small root  which is united  with others
 in the formation of the Diaphragmatic Nerve.
  A Large Branch comes out from it behind the Sterno-
 Mastoideus, whicli, turning over  this Muscle, sends off
 the following Nerves, viz.
  The  Inferior Cutaneous Nerve ofthe Neck, which par-
 ses forwards to the parts under the Lower Jaw.
  The  Middle Cutaneous Nerve, which runs  towards the
angle of the Jaw.
  'The  Great Posterior  Auricular Nerve, which furnishes
 an anterior Branch to  the under part ofthe Ear, and a
posterior  Branch dividing into many others  v.hich go
to the back-part of the Far and Temple. 
                        306                      m
  The Cutaneous and Auricular Nerves are dispenjfl
upon the Platysma Myoidcs,  Integuments of tlie side ofl
the Neck  and Head, the Parotid Gland,  and ExternaM
Ear ; and  have several Communications with the Portio7>
Dura of the Seventh  Pair.
  The remainder of the Second Cervical is distributed 1
upon the Levator Scapulx,  and tlie Extensor Muscles of ■
the Neck and Head.                                  I
  The Third Cervical  Nerve, after emerging  from be.
tween the Vertebrx,  sends down a Branch to the Trunk
of the Fourth Cervical, and another Branch which formj
the principal  root of the Diaphragmatic Nerve.
  A Third Branch perforates  the Muscles on the side of
the Vertebrax, and joins the middle Ganglion of the sym-
pathetic Nerve.
  A Small Filament connects a third Cervical with the
Descendens of the Ninth Pair.
  The Nerve is afterwards  divided into External and In-
ternal Branches.
  The External Branches form Anastomoses with the
Nervus  Accessorius, near the upper part of the Scapula;
while the  Interior after furnishing Twigs to tlie Jugular
Glands are dispersed by several large Branches upon the
Muscles and Integuments at the under part of the Neck,
and upper part of the Shoulder.
  The Fourth Cervical, sends a Branch behind the Mus-
cles situated on the fore aiid lateral parts of the Cervical
Vertebrx, to the middle Ganglion of the Sympathetic
Nerve.
  It is connected by one, and sometimes by two Filaments
to the Diaphragmatic Nerve.                         '
  It gives Twigs to  the Jugular Glands and deep Mus-
cles of the Neck, and at the  outer edge of  the  anterior
Scalenus,  joins the Fifth Cervical Nerve.
  The Fifth Cervical.—is  united with the Fourth into a
Common  Trunk, whioh, after running a little farther'
out, joins  the Sixth Cervical  Nerve.                   i
  The Sixth Cervical,—joins  the Seventh behind the Cla-
vicle ;  and to the Seventh,  the First Dorsal Nerve is ad-
ded over tlie First Rib.
  The Four  Inferior Cervicals and First  Dorsal Ne.rve
are of  great size,—especially the three iuterineTiat*
Nerves. 
307
  Tliey pass out between the Scalenus Anticus  and Me-
dius,—-and afterwards run between the Subclavian Mus-
cle aud First Rib, at the outer side ofthe Subclavian Ar-
tery, to the Axilla.
  In the Axilla, they separate, unite, and separate again,
forming an irregular Plexus, termed Axillary or Brachial,
—which surrounds the Axillary Artery.
  The Axillary Plexus sends Branches to the Subscapu-
laris, Teres Major, and Latissimus Dorsi, and furnish the
External Thoracic Nerves which accompany the Blood-
vessels of that name to the Pectoral Muscles and Integu-
ments.
  The Plexus afterwards divides into Nerves, most  of
which are  of great size,  to supply the Superior Extremi-
ty.—They are as follow.
  The Scapularis,—which  commonly arises  from the
combination ofthe Fourth and Fifth Pairs, and extending
outwards,  runs through  the Semilunar Arch in the up-
per edge ofthe Scapula, afterwards descending between
the root of the Spine and Head of the Scapula.
  It furnishes Branches to the Supra-Spinatus, and is af-
terwards consumed upon the Infra-Spinatus Muscle.
  The Articularis,—which arises like the former Nerve,
from the Trunk common to the Fourth and Fifth Cervi-
cals.
  It sinks, deep in the Axilla,  and  getting between the
under edge of the Subscapularis, and Insertions of the
Teres Major and Latissimus Dorsi, it follows the course
ofthe Posterior Articular Artery round the Body of the
Os Humeri, immediately below1 the  Articulation.
  It sends Branches to the Teres Minor, and some Twigs
to the Ligament of the  Joint; but is  chiefly dispersed
upon the Deltoid  Muscle.
  The Nervus tTtrrm.-eu*,—which arises from the Trunk
Common to the  last Cervical and Fifth Dorsal Nerve ;
but is chiefly formed by Fibrillx from tlie latter.
  It runs down  at the inner and fore-part of tbe Arm,
near the Radial Nerve.
  It sometimes gives *■ small Branch to  the upper part
ofthe Coraco-brachiaUs and Biceps; and, fartlu-r down,
it gives others to the Integuments and Coals ofthe Blood-
vessels.

      V<.iL„ II.             h 
                         306
    About the middle of the Arm, it splits into two Bran-
 cues, an Internal and External.
    The Internal Branch, which is rather the smaller of
 the two, passes before  the Basilic  Vein  to  the  inner
 part ofthe Elbow, where it divides into Branches, two
 of which, larger than the rest turn obliquely over the
 Heads ofthe Flexors of the Hand, to be dispersed  upon
 the inner and back-part  of the Fore-arm.
    The External Branch divides into several others, be-
 hind the Median Basilic Vein, which descend on the an.
 terlor  and Ulnar side of the Fore-arm,  as far as die
 Wrist.
    They pass partly over and partly under the Subcutane-
 ous Vessels  ; furnishing Twigs to these, and vanishing
 in the Integuments.
    Besides the Nervus Cutaneus, there is another termed
 Cutaneus Minor Internus of Wrisbeug, which, like the
 rest of the Nerves of the Superior Extremity, takes o-
 rigin from the Axillary  Plexus ; but is more particular.
 ly connected with the Ulnar Nerve.—It is considerably
 inferior in size to the Nervus Cutaneus.
    It soon separates from the Ulnar,  running afterwards
 between it and the inner side ofthe Arm.
    A little below the Axilla, it splits into two Branches %
   The smaller, turning to the posterior part of the arm
 is divided into Filaments which  are chiefly dispersed
 upon the Triceps and its Integuments.
   The larger Branch descends at the inner edge ofthe
 Triceps, and vanished upon the under end of that  Mus-
 cle and Skin ofthe Elbow,
   The Musculo-Cutaneus, called also Pefforans Caserii,
 —which consists of Fibrillx from almost all the Nerves
 entering the Plexus.
   The Cord  formed by these perforates, obliquely, the
 upper part of the Coraco-brachialis to which it gives
 Branches.
  It afterwards  passes between  the Biceps and Bran-
 chialis Internus, furnishing Branches to both.
  At the Elbow, it gets  to the outside of the Tendon
of the  Biceps, and runs  behind  the Median Cephalic
 Vein.'
  From thence 4t  descends in the Fore-arm, between
'J> Supinator Longus  and Integuments; furnishing 
                        309
 Branches to the latter, as far as tlie root of tfce Thumb
 and back of the Hand.
   The Spiral, or Spiral Muscular Nerve,—which is ap-
 parently formed of all the Nerves entering into the Ax-
 illary Plexus, and when the Sheaths of the Nerves are
 slit open, is found to be composed of Fibrillx from each
 ofthe Trunks, excepting from that of the Fiist Dorsal.
   It is rather larger than any other Nerve of the Supe-
 rior Extremity, and is distinguished by  its Spiral Di-
 rection.
   It is at first situated between the Axillary Artery and
 the Ulnar Nerve, and passes  obliquely downwards be-
 tween the two Heads of the Triceps Extensor Cnbiti,
 and afterwards behind the Os Humeri, to the outside of
 the Elbow.
   From thence it proceeds  among the Muscles of the
 Radial side of the Fore-arm, as far as the hand.
   While passing behind the Os Humeri, it gives sever-
 al Branches of considerable size to the  different Heads
 ofthe Triceps ; some of them accompanying the Bran-
 ches of the Arteria Spiralis, and terminating on  the
 Heads of the Extensors ofthe Hand.
   Immediately behind the  body of the Os  Humeri, it
 transmits a  Subcutaneous Branch, which is distributed
 upon the Muscles  and Integuments on the Posterior
 part of the  Fore-arm, anastomosing at last with the
 Ner\es on the back-part ofthe Hand.
  The Trunk ofthe Nerve having arrived at the Elbow,
 is lodged in a Fissu;*e  between the Brachialis Internus
 and Radial Extensors of the Carpus, and there gives off
 other Branches to the Extensor of the Hand, and to the
 Supinator Muscles.
  At the Head of the Radius, the Trunk ofthe Nerve
 divides into two nearly equal Branches,—the Superficial
 lis and Pnfundus.
  The Superficialis, continued almost straight from the
 Trunk, ••tmifdiatel*. transmits a Branch to the Exten-
sores   radiales and Supinator Longus, and then de»
 scends : t the inner edge of this  Mut.de  along  with tbe
 Haa ...  ..'.ei'..
  A little below the middle ofthe Radius, it crosses be-
tween the Tendon ofthe supinator and  Extensores Ra-
 diates, and is subdivided into a Volar and Dorsal Branch. 
310
  The Volar Branch, after sending Twigs to the Au.
nular Ligament, is distributed to the Muscles and la-
teguments of the Thumb.
  The Dorsal Branch is again subdivided into numerous
other Branches, some of which go to the Muscles in the
interval  of the Metacarpal  Bones  of the Thumb and
Fore-finger, a  few Filaments being distributed to the
Annular Linament, while principal Branches run one a-
long each side ofthe Fore and Mid-finger, and likewise
along the Radial side ofthe  Ring-finger.
  The Ramus Profundus, after sending several Branches
to the Extensores Radiales and Supinator Brevis, per-
forates the larter, and gets to the back-part ofthe Fore-
arm.
  After quitting the Supinator, it descends  under the
Extensor Primi Internodii Pollicis and Extensor Digito-
rum to the back ofthe Hand.
  In this course, it sends Branches to the different Ex-
tensors ofthe Thumb and Fingers, and at length dege-
nerates into a slender Branch, which, at the Wrist, ad-
here* closely to the Annular Ligament, where  it has a
Gangliform appearance, and is dispersed partly  upon
the Membranes on the back  of the Metacarpus.
  The Median or Radial Nerve,—which comes from the
middle and lower part of the Plexus, is formed by Fa-
sciculi from all the Nerves which enter the Plexus, and
is nearly of a similar size with  the Spiral  Nerve.
  It descends in the Ai m along the anterior surface of
the Humeral Artery, to  which, and to the Deep Veina,
it adheres firmly by the Cellular Substance.
  In this course,  it does not give off any considerable
Branches ;—twigs,  howvver, are sent  from it to tin
Coats ofthe adjacent vessels.
  At the bending of the Elbow, it slips over the Ten-
don of the Brachialis Internus, and perforates the back-
part ofthe Pronator Teres Muscle.
  It afterwards passes down between the Flexor Radi-
alis and the Musculus Sublimis, and goes  in the middle
of the interval of the  Radial and Ulnar  Artery  in its
way to the Hand.
  When it approaches the Fore-arm,  it transmits Bran-
ches to the Pronator Teres and Integuments near that
Muscle. 
311
  In the Flexure ofthe  Arm, it furnishes Branches to
the Pronator, Flexor Radialis, and Flexor Sublimis, and
an Interosseous Branch which, in some subjects, receives
an addition from the Spiral Nerve.
  The Interosseous Nerve gives Branches  to the Flexor
Longus Polliets, and to  the Flexor Profundus Digito-
rum,  descends upon the Interosseous Ligament with
the Vessels of that name, and terminates in the Pro-
nator Quadrat us.
  Near the Hand,  it sends a Branch dividing into others
which supply the Muscles and Integuments forming  the
Ball of the Thumb.
   The Trunk of the  Nerve having given Branches to
the Fore-arm, passes under the  Annular Ligament of
the Wrist, where it divides into Branches which are si-
tua\»d behind the Aponeurosis Palmaris, and Superfi-
cial Aru, 0f the Arteries.
   The prinu^i Branches in tbe Palm come off in three
 divisions, from w^ui, seven Nerves of considerable size
 are distributed to the 'rwaib and Fingers.   Of these,
 two go to the Thumb, and one Lo*he Medial side ofthe
 Fore-finger ; the rest come off from two forked Trunks,
 near the Head ofthe Metacarpal Bones, fuid supply the
 adjacent sides of the Fore and Middle, and of-the mid-
 dle and Ring-finger.
   These Brandies send Twig6 through the Aponeuro-
 sis, to the Integuments of the Palm, and others to  tlie
 Musculi Lumbricales ; after which they accompany the
 Arteries sent out from  the Superficial  Palmar  Arch,
 bestowing Twigs to the  adjacent parts of tbe Fingers,
 at the points of which they terminate by numerous Fi-
 bres.
    The Ulnar Nerve,—which, like tlie former, is of great
 size, comes off chiefly from the last Cervical and First
 Dorsal Nerve,
    It extends along the inside of the Triceps, frequently
 perforating  some of ks Fleshy Fibres, and near the El-
 bow, slants  a little backwards, to get into a Groove be-
 tween the inner Condyle ofthe Os Humeri and Olecra-
 non ofthe Ulna.
    From thence it passes to tlie  Fore-arm, where, after
 perforating t!*e Heads of the FJeKor Muscles, it joins
  the Ulnar Artery a little below  its origin, and accoro-
                         s 2 
                         312
 panies that vessel,—running behind it all the way to
 the Hand.
   Under the Axilla,  it sometimes  receives a  Branch
 from the Spiral  Nerve ;  and from  this connection, or
 from the Trunk ofthe Ulnar Nerve itself, a Subcutane-
 ous Branch is sent off, which runs between the Triceps
 and Integuments, furnishing Branches to the latter for
 a considerable way along  the poie arm.
   Near the under end ofthe Os Humeri, a Twig or two
 commonly go to the inner edge ofthe Triceps.
   Under the bending of the Elbow, a Branch is giv*n out
 to be distributed upon the Belly of the Flexor Ulnax's.
   Immediately below the former, another Branch is-pro-
 duced, which is dispersed upon  the Flexor Profundus
 Digitorum.
   About  the middle of the Fore-arm, a Filament is
 transmitted which adheres to the Ulnar Arter.**> furnish-
 ing small Twigs to the Coats and SheaO*"*the Artery,.
 and terminating in the corresponding P»rts of the Wrist
 and Integuments ofthe p«J«n-
   Near the end of the Ulna, a considerable Branch, ter-
 med  Dorsalis, is  sent out, which turning between the
 Flexor Ulnaris and Ulna, is directed to the back-part of
 the Hand.                               ,
   The Dorsal Nerve sends Branches to the  Integuments
 ©f the Wrist and Metacarpus, which have various an-
 astomoses with others ofthe Spiral Nerve.
   It sends off a Branch which proceeds along tbe Ulnar
 side ofthe Little Finger;—and at  the  Heads ofthe
 Metacarpal Bones, another splitting into two Branches
 which run along the adjacent sides of the Auricular and
 Ring-fingers.
   The Trunk of the Nerve passes with the correspond-
 ing Artery over the Annular Ligament into the Palm,
 where, like the Radial Nerve,  it is covered  with  the
 Aponeurosis Pal maris.
   In the Palm,  it divides into  Superficial and Deep
 Branches ; the former destined chiefly for the Fingers,
 the latter  for the deep region ofthe Hand.
   The Superficial Palmar Nerves sends—
  Branches to  ihe short Muscles ofthe Little Finger:
   A Branch to the Volar-Ulnar side of the Little  Fin-
ger :—and—
 
    Another, which is soon  spilt  into two smaller Bran.
 ches; one to the Radial side of the Little Finger, the o-
 Uier to the Ulnar side ofthe Ring-finger.
    lne Deep Palmar Nerve sinks  in betw.en the Abduc-
 tor and Flexor Parvus  Digiti Minimi, or perforates the
 Head of the latter, and forms an  Arch which  accompa-
 nies the Deep  Arch ofthe Arteries under the Tendon of
 the Flexors, and the Lumbricales Muscles.
   The Deep Nerve gives—
   A Branch to the Abductor Minimi Digitr, and one to
 each of the Interosseis .-
   A Twig to  each of the  Lumbricales, which enters
 from  behind :
   Branches to the Flexor*  Brevis and Abductor Pollicw.
   The Nerve terminates at length  by several short Blan-
 ches upon the Abductor Indicia Muscle.
   The Nerves on  the  Palm and corresponding parts of
 the Fiigers, like the Arteries, are much larger than those
 of the opposite side of the Hand.
   The Digital Nerves send off many lateral Branches to
 the Integuments and other  parts of the Fingers, and ter-
 minate, each, by a Brush of Fibres, at the Apices ofthe
 Fingers.
   B<.t*veen the Branches ofthe Radial and Ulnar Nerve,
 different  Anastomoses are  frequently found;  and  the
 same  may be observed between the Nerves ofthe Pal-
 mar ard Dorsal side ofthe  Fingers.
   Inte'costo-Humerales.—Besides the Nerves ofthe Su-
perior Extremity sent from the Brachial Plexus, there
are oilers belonging to it,  which take their origin from
the In crcostal Nerves, and which  may therefore be ter-
 med Dtercnsto-Humerales.
   The Intei costo Humeral  Nerves,—consist of a Branch
fitm tie Second, and of another from the Third Intercos-
tal Ni-rves, both of which pass out  at the Fore and Late-
ral pai !s of the Thorax, the one under the Second, and
the other under the Third Rib.
  'Ihe first Nerve.is joined by a small Branch with the
CuUnems  Nerve, or with  the Cutaneous  Internus  of
WnisrERG, and is afterwards dispersed by numerous
Filaments upon the Axillary Glands, and upon the Inte-
guments of the Axilla and  ofthe inner part ofthe Arm.
   The Second Nerve is connected  by one or more Bran-
                         s  3 
                       314                        m
ches with the First, and sends some Twigs to the Axil-, J
lary Glands ;  but is chiefly distributed upon the Integu-
ments of tlie back-part of the Arm, which it supplies  i
with many Branches, some of them  extending as far as
the Elbow.
*•
NERVES.
WITHIN THE THORAX.
  The Nerves, in each side of the Thorax, consis: ofthe
Phrenic, the Pars Vaga ofthe Eighth Pair, the Grett Sym-
pathetic, and the Intercostals ;  all of which are covered
and concealed by the Pleura, till they are disposed by
dissection.
  The Phrenic or  Diaphragmatic Nerve, has a small Fi-
lament from the Second Cervical: but is chiefly formed
by a Branch from the Third, and by one, and sometime*
by two, from the fourth Cervical Nerve.
  It decends in the Neck, along the outer and fore-part
ofthe Scalenus Amicus Muscle, and enters the Thorax
behind the anterior extremity ofthe First Rib, between
the Subclavian Artery and corresponding Vein.
  In the Thorax it runs down over the root of the Lungs,
and then passes along the Pericardium, to which it ad-
heres closely in its way to the  Diaphragm.
  The Right Phrenic has nearly a straight direction op-
posite to the Superior Cava and Right Auricle; while
the left makes a considerable Curve near its unaerend,
corresponding with that part ofthe Pericardiun which
covers the point ofthe Heart.
  Upon the Surface of the Diaphragm, the Trunk is di-
vided into several Branches, which are distributed in a
radiated form upon the fleshy sides of that Muscle. 
31 a
  Pars Vaga—The Pars Vnga, upon approaching the
Thorax, sends a Filament, and sometimes  t'.vo, teirtied
Cardiac Nerves, which join the Cardiac  Branch of the
Great Sympathetic, as already observed.
  It enters the Thorax  between the  Subclavian Vein
and Artery, and after giving off the  Recurrent Nerve,
passes behind the root ofthe Lungs.
  Recurrent Nerve—The Recurrent,—is reflected up-
wards, behind the  Subclavian Artery in  the right, and
behind the Arch ofthe Aorta in the left side ofthe Tho-
rax ; in consequence of whicli,  the left nerve is the lon-
ger ofthe two.  It afterwads ascends in the Neck, adhe-
ring to the posterior and lateral part ofthe Trachea, in
its way to the Larynx.
  It is connected,  near its origin,  by one or two Bran-
ches of considerable size, with the  adjacent Ganglia of
the Great  Sympathetic  Nerve, and fiom the  opposite
side of its  root,  sends other considerable  Branches to
join those of the Eighth Pair, in the formation ofthe An-
terior Pulmonary Plexus of Nerves.
  Near the Subclavian artery, it is connected by differ-
ent Filaments to the Superficial and deep Cardiac Bran-
ches ofthe Sympathetic Neive-
  In its ascent in the Neck, it transmits Pencils of Fi»
laments, whicji penetrate the Trachea, and are disper-
sed upon its Internal Membrane.
  Behind the Thyroid Gland, it sends off minute Fibres
to the  beginning of the  Esophagus and bottom of tbe
Pharynx aud small Twigs to the Gland itself.
  Upon the inner side of the Thyroid Cartilage, it fur-
nishes a Branch which constitutes a remarkable Anasto-
mosis w ith another from the Internal Laryngeal Nerve.
  At the back-part ofthe Larynx, it is divided into ma-
ny Fibrillx, which  are distributed to the  different Mus-
cles fixed to the Arytenoid Cartilage of the correspon-
ding side.
  It has also some connections, smaller than the one al-
ready mentioned, with Branches of the Internal Laryn-
geal Nerve,  and sends  minute Fibrillx to the Internal
Membrane ofthe  Larynx; from which  circumstance
the Recurrent  Nerves are considered as the principal
Instruments ofthe Organ of Voice.
  The Pars  Vaga,  having transmitted  the recurrent
                        S 4 
                       316
Nerve, gives off filaments which form connection with
Branches arising from the root of the Recurrent ofthe
same and ofthe opposite side.
  They anastomose also by small Fibrillx with the Car-
diac Branch of the Sympathetic, and then pass  to the
fore-part ofthe Bronchi, where they constitute what is
termed the Anterior Pulmonary Plexus of Nerves.
  The Anterior Pulmonary Plexus, thus formed by Bran-
ches from the Eighth Pair, with the assistance of others
from the Recurrent and Sympathetic Nerves,—extends
across the Great Branches of the Pulmonary Artery, (
and after transmitting  small Filaments  to the Pericar*
dium and to the Great Cardiac Nerve, furnishes many
minute Fibrillx, which accompany the Ramifications of
the Bronchi and Pulmonary Blood-vessels  in the Sub-
stance ofthe Lungs.
  From the Pars Vaga, a little below the origin ofthe.
Recmrrent and likewise from the root ofthe Recurrent
itself,  Nerves  are sent off, which form a Plexus, to be
dispersed partly upon the Fleshy-glandular Substance
ofthe Trachea, and partly embracing the OEsophagus,
and forming upon it the small O Esophageal Plexus.
  Behind  the  root of  the Lungs,  about six or seven
Nerves of different sizes are sent off in a tranverse di-
rection, which are termed Posterior Pulmonary Plexus,
although they  have few connections with each other.
  The Posterior Pulmonary Nerves, like  the Anterior
follow tlie Branches ofthe Bronchi and blood-vessels in
the Substance  of the  Lungs, and  becomming gradually
smaller, send off minute Twigs,  which penetrate the
Air-Vessels, and are  ultimately dispersed upon the In-
ternal Membrane.
  After giving out tbe Pulmonary Nerves, the Pars Va-
ga is split into Chords termed Great OEsophagealPlex-
us, which surrounds the OEsophagus, sends Filaments
into its Substance, and is joined by Funiculi ofthe Pars
Vaga of the opposite  side.—It goes afterwards through
the Diaphragm, to be distributed upon the  Vicera of
the Abdomen.
  From the Ganglia of the  Great Sympathetic Nerve,
at the bottom of the Neck and top of the Thorax, the
principal Cardiac Nerves are produced;  which are dsi-
pcraed upon the Heart ; while the  continuation of the 
317
Trunk of the Sympathetic descends in the Thorax at
the side ofthe Vertebrxv
  The Cardiac Nerves ofthe Right Side consist of the
Cardiacus Mugnus Profundus, and Cardiacus  Minor, the
latter of which is termed by ScapraCabdiacus Aorta
Superficialis.
  The Cardiacus Magnus Profundus,—is principally for-
med by Branches from  the Second Cervical Ganglion
ofthe Sympathetic, and afterwards receives one or two
Filaments from the Cardiacus Supremus, together with
the Superficial Cardiac and other Branches ofthe Eighth
Pair, as formerly described.
  The Trunk, arising in this manner from different sour-
ces, passes between the Superior Cava and ascending
Aorta to the Posterior Surface of the latter, and joins
the Cardiac Branches ofthe Left Side.
  By the addition ofthe Left Cardiac Nerves, a Plex-
us is formed, termed Plexus Cardiacus Magmtsof Haller,
from which is sent out a long Ganglion of a soft consis-
tence, described by Wrisbirg under the name of Gang-
lion Cardiacum.
  From the Cardiac  Ganglion, the following Branches
are given off, viz.
  A Branch which, after transmitting Filaments to the
Anterior Pulmonary  Plexus of the Eighth Pair, passes
behind the Right division of the Pulmonary Artery to
the Left Coronary Plexus ofthe Heart.
  One or two Fib ments, which unite with others  sent
from the Anterior Pulmonary Plexus ofthe Eighth Pair,
and go before the Right Branch of the Pulmonary Ar-
tery to the Base of lite Heart-
  Branches of considerable size, passing partly over the
right side of the Aorta, and partly between it and the
Pulmonary Artery to the Anterior Coronary Plexus.
  Small Branches which unite with others coming from
the Trunk of the Great Cardiac Nerve, and pass over
the Aorta to the Anterior Coronary Plexus.
  'The Nervus Cardiacus Minor  arises from  the under-
most Cervical Ganglion, creeps over the Arteria  lnno-
minata and Aorta, and terminates in a Plexus formed
by  the Cardiac Nerves on the leftside ofthe Aorta As-
cendens. 
318
  The Left Cardiac Nerves are, the Cardiacus Supcrfici-
alis, and the Cardiacus Magnus Profundus.              ;
  The Cardiacus Superficialis arises from the upper part  j
ofthe Sympathetic Nerve, as formerly noticed, and pas-
ses behind the Arch of the Aorta to the Plexus Cardi-
acus Magnus.
  The Cardiacus Magnus Profundus Sinister, the upper
portion of which is smaller than that of the right side,
arises by numerous roots from the middle, and from the
lowest Ganglion ofthe Sympathetic Nerve.
  It passes across  the Arch ofthe Aorta, and, after re-
ceiving the Cardiac Branch of the Eighth  Pair, joins
the Great Cardiac of the right side, to assist in forming  |
the Cardiac Plexus.                                  ,
  From the Cardiac Plexus, a Recticulum of Nerves  \
extends upwards on the left side of the ascending Aorta
which receives the Cardiacus Minor, and a Filamentor  ,,
two from the Cardiacus Magnus of the right side, pas-  j
sing over the Aorta.                                  ,
  From this Recticulum, the Anterior or Right Corona-  '
ry Plexus is produced, which passes between tbe Pul-
monary Artery and Aorta, and afterwards  follows the
course of the Trunk  and Branches of the Right Coro-  •
nary Artery, along with which it is dispersed upon the
corresponding side of the Heart.
  The Great Cardiac Plexus, after sending a Filament
or two to the Lungs, gives off Nerves which unite, and  '
form the Trunk ofthe Great Deep Cardiac Nerve ofthe
left side,  which has a soft Gangliform appearance, and
passes along the corresponding side  of the Pulmonary
Artery.
  Upon the Surface of this Artery, the Trunk  soon di-
vides into Branches, which,  after sending Filaments a-
cross it to the Right Coronary Plexus, gives origin  to
the Coronary Plexus ofthe left side,  which  attends the  ;
Trunk and Branches of the Left Coronary Artery.
  In the Left or Posterior Coronary Plexus, the Nerves
are larger than  in the Right,  corresponding with the  i
Parts they have to supply;  and, in both, they have re-
peated connections with each other  on  the surface  of
the Heart.                                          '
  Jn general, the  Nerves  run close  to the Arteries » m 
319
  some of tbrm being continued as far as the Apex, while
  others penetrate the substance ofthe  Heart.
    The Great  Sympathetic, having sent Nerves to the
  Heart, consists  of an Anterior and posterior part, the
  former going over, and the latter under the Subclavian
  Arterv-
    Behind this Artery, the two parts unite into a Trunk,
  which descends in the Thorax over the  Heads of the
  Ribs.
    At the Head of each Rib, it forms  a small Ganglion
  of an irregular shape, which unites behind with each of
  the Intercostal Nerves, generally by two, and sometimes
  by three  short Branches.
    From several ofthe Dorsal Ganglia of this Nerve, Fi-
  laments are detached obliquely over the Vertebrx to tlie
  Coats of the Aorta
    From the  Sixth, Seventh, and Eighth Dorsal Gang-
  lia.—and frequently from a Ganglion above or below
  these,—Branches arise, which  descend obliquely upon
  the sides of  the Vertebrx, and unite into a Trunk, ter-
  med Nervus Splanchnicus,—which perforates the Appen-
 dix ofthe Diaphragm, and goes to  the Viscera of the
 Abdomen, from  which circumstance  the Nerve  ob-
 tains its name.
   Besides the  Nervus Splanchnicus, another,  termed
 Splanchnicus  Secundarius, or Accessorius, is generally ob-
 served, which arises from one or two  ofthe Dorsal Gang-
 lia, below the organs of the Splanchnicus,—near its ter
 mination,-—or runs separate from it  into the Abdomen.
   The Intercostal, or Costal, or Dorsal Nerves,—after
 escaping from the Vertebrx,—run in tlie Furrows at the
 lower edges ofthe Ribs, in company with the Intercos-
 tal Blood-vessels, and proceed to the anterior part ofthe
 Thorax, between the two Layers of Intercostal Mus-
 cles.
   Immediately  after getting out from between the Ver-
 tebrx, each  is connected, as already noticed,  by short
 Branches to the Sympathetic Nerve.
   Opposite to this connection, they give principal Bran-
 ches  backwards, to  the Muscles lying near the  Spine,
 and serving for  the  erection ofthe Trunk ofthe Body,
  Through the  rest  of their course, they give Branches
to the Intercostal  Muscles,  to the Muscles andintegu- 
320
ments of the Thorax, and also those of the Abdomen,
and becoming gradually smaller, they at last vanish in.  I
the fore-part of the Body.                            I
  The Six upper Intercostals send Branches to the mi-  ]
merous Muscles, and to the Integuments covering the
back-part of the Thorax, to the Serratus Magnqg, g^  i
to the upper part of tlie Abdominal Muscles ; whilevhe
remains of them, passing out between the Ribs at the
edge ofthe Sternum, are reflected along with Branches
eftbe Internal Mammary Blood-vessels, to be disper-  *[
ped by small Filaments upon the Mamma, and likewise
upon the Muscles and integuments next the edge ofthe
Sternum.
  Tie Trunk of the First Intercostal enters the compo-
sition of the Axillaa-y Plexus ;—a Branch of it, however  <
runs along the edge ofthe first Rib, in the manner the
other  intercostals run along their respective Ribs.
   Two principal Branches,—one  from the second, and
tlie other from the third  Intercostal,—are occupied it
forming the Intercosto-hu-meral  Nerves, already des?
crtbed ;  while a considerable Branch from the Fourtb
is reflected over the edge of the- Latissimus Dorsi In  |
tbe latepuinents of the hack-part of the Thorax.
   The Six lower Intercostals, after supplying  the ad-
jacent Muscles  and Integuments of tbe Thorax, coati- -
mie their course obliquely forwards, and are disperse! .?
 upon  the different Muscles and Integuments of tie Ab.
 domen ;—tlie Twelfth, panning from the last Rib slong
 the under end ofthe Abdomen, sends Filaments wbicb
 extend «« far as the Skin of the Pelvis and Thigh- 
NERVES
OF THE CHYLOPOIETIC  AND ASSISTANT

         CHYLOPOIETIC VISCERA.
  The Nerves ofthe Chylopoiettc and Assistant Cbylo-
poietic Viscera, are formed by Branches, of the Par Va-
gum, and the Rami Splanchnici ofthe Great Sympathetic
fair-
  The Pars Vaga of the Left Side,—descending from the
Great OEsophageal Plexus of the Eighth Pair, creeps  a-
Iong the fore-part  of the Cardia, detaches Filaments  to
the Left Hepatic Plexus, and divides into many Branches
which are distributed to the upper and left portion of the
Stomach.
  The Right Pars Vaga passes upon  the posterior part  of
the Qardia, and splits into  two Fasciculi, one of which
goes to the Root ofthe Hepatic Plexus, and to the Cccli-
ac Ganglion, while the other, which is the principal one,
is dispersed by numerous  Branches upon the under and
left portion of the Stomach.
  The Nerves ofthe two Fasciculihave several connec-
tions  with each other, about the Cardia and along the
small Curvature of the Stomach, and form a  Plexus, by
some  Authors termed Coronary, from  which Branches
extend along the small Curvature as far as the Pylorus.
  The  Ramus Splanchnicus and Splancjuiicas Sccundarius
have their ojygins from the  Sympathetics, and perforate
the upper and Lateral part ofthe inferior Muscle of tlie
Diaphragm,—as already mentioned in the Description  of
tlie Nerves of the Thorax..
  After entering the ATidomen,tiiey expajkl tfeeir Fibres
and unite with tbe  lateral part of the Great Semilunar
 Ganglion.
  The Semilunar Ganglion »is firmed by tit* Rami Splanch- 
322
 nici of tlie Right and Left Sympathetics, with the addi-
 tion ofthe Branches from the Eighth Pair.
   It is of a long curved shade, with the convex edge un.
 dermost, and is composed of many smaller Ganglia, term.
 ed C*Uac, which are of different size and of irregular
 forms.
   The Caliac Ganglia are placed over the  Aorta, about   \
 the Roots of the  Cccliac and Superior  Mesenteric Arte-
 ries,  and extend some way upon the Fleshy Pillars of
 the Diaphragm.
   From the Cccliac Ganglia innumerable  Nerves issue on
 all sides, forming a  Plexus, termed by some Authors So-
 lar, which extends along the Trunks and Branches of the
 Cceliac and Superior Mesenteric Arteries.
   The Nerves  upon these  Arteries are so intermixed
 with each other and with Cellular Substance, as to form
 confused Webs;  the name of  Plexus, however, is Mtift-
 retained, and the  particular name of each Plexus is deri-
 ved from the Artery which  it surrounds, or the  Viscusto
 whicli it belongs.
   The Hepatic Plexus —after giving Twigs  to the Renal
 Glands, sends Filaments to the Diaphragm, which ac-
 company the Diaphragmatic  Arteries, and  anastomoses
 with  Branches of the Phrenic Nerves.                   f
   It afterwards  divides into Right and Left Plexuses,   v
 corresponding with  the Right and Left Branches of the
 Hepatic Artery, or with the Right and Left Trunks when
 such are present.
  The Left Hepatic Plexus furnishes several Branches to
 the Stomach, which intermixes with those ofthe Eighth
 Pair, upon the small Curvature.
  Tlie Right  Hepatic Plexus imparts Branches to the
 Corresponding part of the Pancreas,  to the small end of
 the Stomach and beginning ofthe Duodenum, and gives
origin to the Right Gastro-epiploic Plexus, which attends
 the Artery of the  same name, distributing its Filaments
 to the  Great Curvature of the Stomach, anil to the O-
 mentum Majus.
  The Hepatic Plexuses surround the  Hepatic Artery
and Vena Portx, and after sending several  Filaments to
the Biliary Ducts  and Gall-Bladder, follow the Branches
ofthe Blood-vessels  through the substance ofthe Liver.
  The Splenic Plexus, composed of several small Fila-  I 
                        323
ments, surrounds the Splenic Artery, gives Twigs to the
Pancreas, and  then  accompanies the Vessels into  the
Spleen.
  The Superior Mesenteric Plexus, forms a Vagina, which
surrounds, and in a great part conceals the Trunk of the
corresponding Artery.
  From this Plexus, numberless Filaments are produced,
—many of them Extremely minute,—which run through
the Mesentery, partly with the Blood-vessels,  and partly
at a dist-mce from them ; and which, after supplying the
Coats of the Vessels and Mesenteric Glands,  are distri-
buted to the small Intestines in general,  and to the right
portion ofthe Colon.
  The Nerves of the Colon are, in proportion to the part
they have to supply, larger than those ofthe small Intes-
tines, and in several places form Arches, which are situ-
ated at the sides of the  Arteries.
  'The Cccliac  Ganglia  send down,  along  the Aorta, a
Vagina similar to that surrounding  the Superior Mesen-
teric Artery, which is joined by other Nerves from  the
Trunk of the Sympathetic continued along the Lumbar
Vertebrx.
  From the Aortic Vagina or Plexus,  a  process  is  sent
off, termed Inferior  Mesentery  Plexus, which surrounds
the Trunk of the Inferior Mesenteric Artery, and  follows
it to the left portion ofthe Colon, and to the Rectum ;—
the Nervous Filaments  forming Arches in several places
as in the Superior Mesenteric Plexus.
  The Aortic Plexus  receiving fresh supplies from the
Trunks of the Sympathetics, sends down a Plexus, com-
monly termed Hypogastric, which  passes over the  end
of  the  Aorta,  and, upon the last Lumbar Vertebra,
splits into right and  left portions, which descend to
the Viscera contained in the Pelvis* 
                 NERVES

OF THE  ORGANS OF URINE  AND GENE-

                  RATION.
  The Nerves of the Organs of Urine and Generation,
consist ofthe Renal and Hypogastric Plexus, and of tlie
Spermatic and Pudic Branches.
  The Renal Plexus is composed of Nerves sent from the
Cceliac Ganglia joined  by some others derived from one
or two of  the Ganglia, of the Sympathetic Nerve in tlie
bottom of the Thorax.
  It is interspersed, at its beginning, with small Ganglia,
termed Renal, and is  afterwards divided into Anterior
and Posterior Plexuses, which  extend along the corres-
ponding Surfaces of the Renal Artery to  the Substance
ofthe Kidney.
  From the Renal Plexus, small nervous Twigs  ascend
to the Renal Gland, which is furnished with others from
the Caeliac Ganglia and Root of the Hepatic Plexus.
  The Renal Plexus also sends down Filaments to sup-
pry the upper portion of the Ureter ;—the under  receiv-
ing Nerves from  the Hypogastric Plexus.
  The Hypogastric  Plexus,  the origin and  course  of
which have been  already mentioned, is connected by dif-
ferent Nerves to the adjacent Trunks of the Great Sym-
pathetic and Sacral Nerves, and sends many Filaments
to the Rectum, Bladder,  and Spermatic Vessels in tbe
Male  ; and to the Rectum, Bladder, Uterus, and Va-
gina in the Female.—The  Nerves  of the Uterus  are
proportionally  small.  They pass  into its substance at
the Cervix, and follow the course ofthe Blood vessels.
  Spermatic Nerves —The Spermatic Nerves are very
minute—They consist of  a Superior or Internal, and of
an Inferior or External set of Capillary Branches.
  The former  are derived from the  Renai and Aortic 
325
Plexus, and accompany the  Spermatic Blood-vessels in
their course through the Abdomen, and afterwards to
the Testicle.
  The latter are sent off from a Branch  of the Second
Lumbar Nerve, which running behind the Tendon of
the External  Oblique Muscle, near Pou part's  Liga-
ment, detaches a Filament, which in the Male, goes to
the Spermatic Cord, and more particularly to the C re-
master Muscle ; and in the Female, is reflected  along
the Ligamentum Rotundum to the Uterus.
  NerviPudici.—The Nervi Pudici arise in two Fasci-
culi,—a Superior and Inferior—which are formed by Fi-
brillx from all the Cords entering the  composition of
the Sciatic Nerve.
  The Superior Fasciculus is formed more particularly,
by Threads from the two under Lumbar and two upper
Sacral Nerves ;—the inferior is composed of a  small
Cord from the Second, and a large one from the Third
Sacral.
  The Fasciculi pass through the under part of the
Notch of the  Os Ilium, and afterwards between  the
Sacro sciatic  Ligaments, and follow the Pudic Blood-
vessels, anastomosing in some places with each  other
by oblique Branches.
  They send off many Branches to the Muscles and o-
ther parts about the Anus and Peritoneum, and then
pass forwards to supply the different parts of the Penis.
  On the Penis, the Nerves follow the course of the
Arteries, the  Superior Fasciculus constituting theNer-
vus Dorsalis,  and  the  Inferior giving Branches to the
under part ofthe Penis.
  The Nervus Dorsalis which is the most considerable
of the Penis, runs forwards between the corresponding
Artery  and Vena Magna, expanding into many Bran-
ches which after supplying the Corpus Cavernosum and -
Teguments ofthe  corresponding side, terminate in  the
Substance of the Glands.           \
VOL.  II.
T 
NERVES
                     or THE

L.OINS, PELVIS, AND INFERIOR EXTREMITY.

  The Nerves ofthe "Loins,  Pelvis, and Inferior Extre-
mity, consist of the continuation or Inferior portion of
the Sympathetic, and of the Trunks and Branches of
the Lumbar and Sacral Nerves.
  The Sympathetic Nerve, after reaching the Abdomen,
makes a sweep forwards upon the anterior and lateral
part of the Lumbar Vertebrx, between  the Tendinous
Crura of the Diaphragm and the Psoas Muscle.
  It afterwards descends into the Pelvis, nearly of the
same size as in the superior parts ofthe Body, and pas-
ses over the Surface of the Os Sacrum, at the inner side
ofthe Great Sacral Foramina.
  Towards the lower part of the  Pelvis, it becomes
considerably smaller, and at last finishes its course up-
on the susface of the Os Concygis, where it unites into
an Arch with its fellow ofthe opposite side.          " 'i
  In the  Loins, it forms Ganglia, similar to those in the
Thorax, each of which is connected behind, by two or
three long slender Branches, to the roots ofthe Lum-
bar Nerves, and before by other slender Nerves to the
Aortic Plexus.
  In the Pelvis also, it forms Ganglia which are con-
nected to the Sacral Nerves on one side, and to the
Great Sympathetic on the other, by cross Branches.
  Filaments are sent off in the Pelvis, from the Sympa-
thetic to  the Muscles  and  Membranes about the Oa
Coccygis, and to the Intestinum Rectum.

                 Lumbar Nerves.

  The Five Lumbar Nerves,  immediately after emerg-
ing from the Bones, communicate with each other, and 
327
with the Sympathetic Nerve, and send large Branches
backwards to the Muscles and Integuments on the pos-
terior part of tlie Loins.
  By their connections with each other, they compose
a Plexus termed Lumbar, which is situated behind the
Psoas Muscle, and  sends  Branches  outwards  to the
Qpadratus Lumborum, and to the Flexors of the Thigh.
  The First  Lumbar Nerve is  connected by  a small
Branch to the Twelftli Dorsal, and by its Trunk to the
Second Lumbar.
  It gives  Twigs to the Qitadratus, and a principal
Branch  which  passes  over that  Muscle towards the
Spine of the Os Ilium, where it  sends Nerves to the
Integuments of the Pelvis, to the upper and outer part
ofthe Thigh, to the under end of the  Abdominal Mus«
cles, and to the Integuments ofthe Pubes.
  The Second Lumbar perforates the Psoas, to which it
gives Branches,' and afterwards runs into the Third.
  From the  Second Lumbar, the Spermaticus Externus
is sent off, which perforates the under part of the Trans-
verse and Internal  Oblique Muscles,  near the anterior
end ofthe Spine, or Crest ofthe Ilium.
  It goes next under the Tendon of the External Olique
at the inner side of  Po up art's Ligament, and passing
through  the  Abdominal Ring,  is distributed  to the
Scrotum and to the  Spermatic Cord in the Male.
  In the Female, it  sends a Branch to the  Labia, and
another reflected along the Digamentum Rotundum, to
the Uterus; and in both Sexes» it gives Branches also
to the Integuments  and  Glands ofthe Groin.
  Another Branch, smaller than the former, arises also
from the Second Lumbar,  and  passing between the
Psoas Muscle and Vertebrx, constitute the Cutaneous
Medius ofthe Thigh.
  The Cutaneous Medius descends in the fore-part of the
Thigh, opposite to the inner edge of the  Rectus Mus-
cle, and supplies  the Integuments near it as far as the
Knee,—one Branch of it anastomosing with another of
the Cutaneus Anterior.
  Branches ofthe Second, Third, and Fourth Lumbars,
form a  Nerve of considerable size, called  Obturator,
which passes between the  External and  Internal  Iliac
Blood-vessels, and along the side of the Pelvis. 
                       328
  The Obturator Nerve accompanies the Blood-vessels, ■
ofthe same name, through the upper part ofthe Obtu- ■
rator  Muscles  and Ligament,  and having furnished a
Branches to the Obturator and Pectineous Muscles,  it ■
divides into Anterior and Posterior Fasciculus ; the for- ■
mer dispersed upon the two small Adductors and Gra- ,
cilis, the latter upon the Great Adductor of the Thigh. /■'
  The principal parts of the Trunks of the four upper
Lumbar Nerves,  especially  of  the^ Third and Fourthfoj
unite and form a Nerve of great  size, termed Crural, or
Anterior Crural.
  The Crural Nerve, after bestowing Branches upon the
Iliacus Internus, passes  behind, then at the outside of
the Psoas Muscle, to get to the Thigh.
  In its course from the Abdomen,  and at the upper
part of the Thigh, it is  situated at the outside of the
Femoral Artery, which lies between it and the corres-
ponding Vein.
  Behind Podpart's Ligament, it is divided into many
Branches, which are distributed to the Muscles and In-
teguments on the fore and lateral parts of the Thigh,—
one Branch in particular descending upon the Leg.
  The Branches are as follow :
  The Cutaneous Anterior,—more  internal than the Cu-
taneous Medius, which crosses  over the middle of the
Sartorius  Muscle, and after supplying the adjacent In- ,
teguments, terminates in the Skin and Cellular Sub- '
stance, at the fore and inner part ofthe Knee-
  The Cutaneus Internus,—still  more  internal than the
former,—which passes between  the Sartorius and Tri- 1
ceps, and, after giving Filaments to the Integuments at
the inside of the Thigh, terminates in those at the un-
der and fore part of the Knee.
  The Deep Branches of the Crural  Nerve, which are ,
considerably larger than the Superficial, go to the Pec- :
tineus  and Triceps,  to the Sartorius and Gracilis, and to
the Four Extensors of the Leg, and  furnish Twigs  to
the Femoral Blood-vessels also.
  The Branch to the Leg, termed Saphenus, descends
between the Sartorius and Triceps, and afterwards be-
hind the Tendon of the former, to the inner side of the
Tibia.
  Under the Knee, it gives off a  Branch, named Fisch- 
329
 er, Saphenus Minor, which goes down a little behind the
 Saphenus, and, furnishing Filaments to the Integuments
of the inner and back-part of the Leg, terminates be-
hind the Malleolus Internus, on the Integuments ofthe
Foot.
  The Trunk ofthe Saphenus attends the Vena Saphena
Major, sending many Nervous Threads obliquely for-
wards to the Integuments on the inner and fore-part of
the Leg, and is at length consumed  upon  the Skin and
Cellular Substance of the upper and inner part ofthe
Foot.
  The remaining part of the  Fourth Lumbar Nerve
unites with the Fifth into a Trunk which descends into
the Pelvis.
                   Sacral Nerves.

  The Sacral Nerves consist of small Posterior, and large
Anterior Trunks.
  The Posterior Sacral Nerves pass out by the Holes in
the back-part of the Os Sacrum,  and anastomose with
each other, and with some of the Branches of the Glu-
teal Nerves.
  They send out a few tender Fibrillx, whicli are disperi-
sed upon the Muscles covering  the back-part of the
Os Sacrum, and upon the Glutei Muscles and their In-
teguments.
  Anterior Sacral Nerves-—Ofthe Anterior Sacrals,—
the two uppermost are the largest :  The rest suddenly
diminish in size, the last being the smallest ofthe Spi-
nal Nerves.
  They go through the Holes in the fore-part ofthe Qs
Sacrum, and, soon after tlieir exit, are united with each
other,  and with Branches ofthe Sympathetic Nerve.
  The First,  Second,  and  Third Sacrals, jqin into a
Trunk, which receives the common one sent dowti from
the  Fourth  and Fifth Lnmbars,  and forms  a  Plexus
which  sends out the Sciatic, the largest Nerve of the
Body.
  The roots ofthe Sciatic Nerve, give origin to tbe Fa-
sciculi which compose the Pudic Nerve, formerly des-
cribed, and also to the Gluteal Nerves  which are dis-
persed upon the Muscles ofthe Hips.
  'The Gluteal 2Jervct  run in two Fasciculi,—a Superior
                        T 2 
                       330                        J"
arising immediately from the Trunk formed by the two |||
last Lumbars, and—an Inferior, coming off from the two
last Lumbars and first Sacrals.                         '
  The Superior Fasciculus goes through the upper part  ]J^
ofthe Notch ofthe Os Ilium, to be dispersed upon the   ,
two smaller  Glutei Muscles.                           '
  The Inferior Fasciculus passes through the under part
ofthe same  Notch, and below the Pyriform Muscle, to
be distributed upon the Gluteus  Maximus and  Integu-
ments.
  The Fourth Sacral sends Filaments of the  Hypogas-
tric Plexus,  others to the Muscles  and  Ligaments of
the Os Coccygis ; the rest  pass outwards to the Mus-
cles and Integuments about the Anus.
  The Fifth, which is scarcely above the size of a Fila-
ment,  after   giving Twigs  to the Coccygeus  Muscle,
perforates the Sacro-sciatic Ligaments, and terminates
in the Muscles and Integuments ofthe Anus.
  Sciatic Nerve-—The Sciatic or Ischiatic Nerve,—pas-
ses obliquely through the Notch of the Ilium, under the
Pyriform Muscle.   It goes afterwards over the other  j
short Rotator Muscles,  and is placed between  the  Tu-  jl
ber Ischii and  Trochanter Major, where  it  is covered  Ml
by the Gluteus Maximus.                            pi
   After leaving the Pelvis, it descends in the back-part  y
of the Thigh, first upon the Long Flexors and Adductor  1
Magnus, and then between the latter and Os  Femoris
to the Ham, where it obtains the name of Popliteus.      |J
   In this  course, it  gives  out the following Branches,   J
which supply the Muscles and Integuments on the back-   fl
part ofthe  Thigh, viz.
   Twigs to  the Rotators of the Thigh, which  come off
from it after its passage through the Sciatic Notch.      ■
   The Cutaneous Posterior Superior,  which arises  within   |
the Pelvis,  and passing out with the Sciatic,  is divid-
ed into Branches,  some of which are reflected  to the
 Scrotum in  the Male, add to the posterior parts  in the
 Labia in  the Female, and, in both, to the Skin about
the Anus and Perineum.—The principal Branches of this
 Nerve pass downwards, supplying the Integuments of
 the back part ofthe Thigh, as far as the bending ofthe
 Knee.                                               ^
   A  Branch to the^long Head ofthe Biceps. 
                        331
  Two small Nerves, the one termed Cutaneus Internus
Superior, which comes oft"  near  the  upper part of the
Thigh,  and vanishes in the  Skin, a little farther down ;
the other termed Cutaneus Internus Inferior, which ari-
ses from the former, goes down the posterior part of
The Thigh, and then descending upon the inner Head of
the Gastrocnemius Externus, terminates in the Integu-
ments of the  Calf of the Leg.
  A Large Common Trunk, and sometimes, instead of
it, separate Branches, which arise near the middle of the
Thigh, and are distributed  to  the Adductor Magnus,
Semimembranosus, Biceps, and Semitendinosus.
  Nervus Popliteus.—The Popliteal Nerve is situated be-
tween the Ham-strings, and between the Skin and Pop-
liteal Blood-vessels.
  A little  above the bending ofthe Knee, it is divided
into a small External, and a large Internal Branch ; the
former named Fibular,  and  the latter Tibial Nerve.
  The Tibial and Fibular Nerves adhere, for some way,
by  Cellular Substance,  and  even the Trunk ofthe Scia-
tic may he split into these two Nerves for a considera-
ble  way up the Thigh.
  The Fibular,—termed also Peroneal Nerve,—sends off,
at its beginning, the Cutaneus Externus, which is a small
Branch giving Twigs to the under end  of the Biceps,
and which, after running down on the outer Head of the
Gastrocnemius, disappears in the Integuments  of the
same side ofthe Leg.
  Over the outer Condyle  ofthe Os Femoris, it gives
oft'another Cutaneus Branch, which goes over the  Gas-
trocnemius Muscle, and, after  anastomosing   with a
Branch ofthe Tibialis, goes along the outer part ofthe
Leg, and terminates in the Integuments of the side of
I he Foot.
  The Fibular Nerve afterwards passes  over the Head
r-f  the Fibula,  and divides into  Superficial and Deep
Branches, which supply the Muscles and Integuments
ofthe outer and fore-part ofthe  Leg.
  The Superficial Fibular  crosses over the Fibula, im-
mediately under its articulation, and perforating the Pe-
roneus  Longus, and going over the Brevis,  it gives
Brunches to  both, and  afterwards becomes Subcutane
ous, about the middle ofthe outer parts of the Leg.
                        T  3 
332
  It sends Branches to the Matatarsus, to the Extensor
Digitomm Brevis, and others, which, after anastomo-
sing upon the upper part  of the  Foot,  furnish Dorsal
Branches to both, and afterwards becomes S ibcutane-
ous, about the middle of the outer parts of the Leg.
  It sends Branches to the Metatarsus, to the Extensor
Digjtorum Brevis, and others, which, after anastomo-
sing upon the upper part of the Foot, furnish Dorsal
Branches  to the larger Toes.
  The Deep  Fibular Nerve crosses over the Fibula im-
mediately above  the former, and divides into several
Branches, viz.
  A Reflected Branch to the soft parts ofthe Joint :
A Branch to the Pe; ioneus Longus :
  A Branch to the Tibialis Anticus :
  Branches to the Extensor Pollicis, and Extensor Digi-
torum Longus:
  Filaments which creep tlong the  Periosteum of the
Tibia, and others which adhere to the Coats of the Ti-
bial Artery.
  The longest Branch of  the  Nerve  accompanies the
Anterior Tibial Artery, and divides upon the Foot into
Branches, which have some connections with each otlier,
and supply the Extensor  Digitorum Brevis.—Some Fi-
laments continued from  the Branches run to the Mus-
culi Interossei, while others of more considerable size
go to  some of the innermost Toes, one 'Twig sinking
with a Branch of the Anterior Tibial Artery to  the
Deep Muscles ofthe Sole.
  The Tibial Nerve passes between tile Heads of the
Gastrocnemius Muscle, and after perforating the origin
ofthe Soleus, descends between it  and the Flexor Di-
gitorum Longus,  upon the  Posterior Tibial  Artery, to
the under part ofthe Leg ;  in which course it sends off
the following  Nerves, viz.
  The Communicans  Tibia,—which accompanies the
Vena  Saphxna Minor in the back-part of the Leg, and
to the outer part of the Foot.
  Behind  the Belly of the Gastrocnemius,  the Com-
municans  sends a Branch  to  be consumed in the Fat ;
and a little lower, it anastomoses with the communicat-
ing Branch of tlie Fibular Nerve.
  The under part of this Nerve is dispersed upon tike 
333
Integuments of the outer Ankle and Adjacent side of
the Foot, some Branches passing as far as the Dorsal
side of two or three ofthe smaller Toes.
  Branches to both Heads of the Gastrocnemius, to the
Plantaris, and to the Soleus-
  Near the middle of the Leg, it sends Branches to the
Tibialis Posticus, to the Flexor Digitorum  and Flexor
Pollicis,
  One or two Cutaneus Branches, dispersed upon the
Skin at the under and inner part ofthe Leg.
  Near the Ankle a Branch which  passes  behind the
Tendo Achillis, principally  to the Integuments of the
outer and back part of the Foot.
  The Tibial Nerve passes  afterwards between the Ar-
teries and Os Calcis into the Sole.
  In the  hollow ofthe Os Calcis, after detaching Bran-
ches to the parts adjacent,  it divides into Internal and
External Plantar Nerves, which are nearly of equal size.
  The Internal Plantar Nerve runs near the inner side
ofthe Sole,  sends Filaments  to the  Abductor  Pollicis,
Flexor Digitorum Brevis, and Flexor Digitorum Acces-
sorius, and Twigs to the Lumbricales.
  It afterwards gives  out four large Branches  splitting
into others, which  run with the Arteries  along  the
Plantar sides ofthe three first Toes, and inner side ofthe
fourth Toe,—in the  manner  the Radial Nerve runs a-
long the  corresponding Fingers.
  The Flxternal Plantar Nerve,  sends Branches to the
Heel, and passes with the  Artery  of the  same name
to near the outer edge of the Sole,  where  it splits in-
to three Principal Branches.
  The two first run to the adjacent sides ofthe fourth
and fifth Toes,  and outer  side of the Little Toe, the
inner one often anastomosing  with a corresponding
Branch ofthe Internal Plantar.
  The third  forms an Arch corresponding with that
of the External Plantar Artery, furnishes Branches to
the short Muscles ofthe  Little Toe, to the  Interossei,
Lumbricales,  and Transversalis, and terminates in the
short Muscles ofthe Great Toe.
  Tbe Plantar Digital Nerves send  Filaments, and up-
on the Toes anastomose  with each other,  and  with the
Dorsal Digital Nerves,—as  the Palmar Digital  Nerves
do in thelland.              T 4 
INDEX  TO
           FYFE'S  ANATOMY.

               VOLUME SECOND.

                    Page- Aquxductus Fallopiit     64
 Abdomen, Ofthe     110       —Sylvii,         22
>     —,  superficial        Aqueous humour,       38
  lymphatics of the         Archnoidea tunica,      14
  under part of the     194 Arbor vitx,             23
 ■     —, Blood-vessels     Arch ofthe Aorta,     215
  of the containing part     Arches of the  palate,    74
  of the               260 Arcus plantaris arterio-
 Abducentes, or sixth         sus,                 273
  pair of Nerves,       287       volaris profundus 239
 Absorbent System, of the 188 ————superficialis,   240
 Accessory nerves to the     Arteries, of the        208
  eighth pair,          297 Articular nerve ofthe
 Acervulus cerebri,      23   shoulder,            307
 Acusticus nervus,     288 Arytenoid cartilages     78
 Adductor oculi,         44 Auditorius nervus,     288
 Adeps,                  9 Auricles of the heart,    91
 Adipose arteries & veins 256 Auris transversus,       54
 Alx vespertilionis,     165 -----internus,        60
 Albuginea tunica,      151 Axillary artery,        V3S
 Almonds of the ears,    75 ■       glands,        209
 Alveolar arteries,       220-----plexus,         307
 Amnios,              180 Azygos vena,          245
 Annygdalx,             75 Ball of the eye,         31
 Anthelix,               52 -------, coats of the   ib.
 Antitragicus, ">         54-------, humours of   38
 Antitragus,   y                 -—, muscles of    43
Aorta, general course of    ——----.vessels of      45
  the                 215 -------, nerves of      46
 Appendages of the skin   7 Basilar artery,         227
 Appendices vermiformes    Basilica vein,          242
  ofthe cerebellum      23 Bladder of Urine       147
 Appendix vermiformis      Bladder of urine, blood-
  ofthe cxcum        119   vessels ofthe        255
 Aqua labyrinthi,         65 -----lymphatics ofthe 195 
335
                      page.
 Blood-vessels in gene-
   ral, ofthe           208
 Brachial artery,       236
 ■  '  »   plexus of nerves, 307
 Brain, of the,            10
 ——, arteries of the   224
 ----, veins ofthe     < 232
 • ■"  , nerves which a-
   rise from the        281
 Bronchi,              103
 Bronchial arteries and
   veins,         107—245
 Buccales arterix,      220
 Bulb ofthe Urethra,   159
 Ccccum intestinum,    119
 ----, absorbents ofthe 197
 Calamus scriptorius,     24
 Canals of the cochlea,    61
 Capsulx renal *s,       146
 —, lymphatics of the 200
 Cardia,               114
 Cardiac nerves,       317
 Carotid arteries,       217
 ----artery, external,    ib.
       , internal,       221
 Caruncula  lacrymalis,    30
 Cauda equina,         302
 Cava, general course of
   the                 215
 ——, superior,         246
 ----, inferior,         276
 Cawl,                 122
 Cellular substance,       5
 Centralis retinx arteria, 223
 Centrum ovale of Vieus-
   sens,                 17
 .----semicirculare gemi-
   num                  1°
• Cephalic Vein,        242
 Cerebellum,             23
 ,___—, arteries of the 227
 Cerebral arteries,      224
                     page.
Cerebrum               15
Cervical nerves,    304—6
Cheek,                 68
Chorda tympani,    57.240
Chorion,              180
Choroid coat,           34
— plexus,             18
Chylopietic and Assist-
  ant Chylopoietic Vis-
  cera, of the         111
----blood-vessels ofthe 247
----absorbents of the  194
321
 29
223
230
 34
 29
 3C
----nerves of the
Cilia,
Ciliary arteries,
----veins,
---- circle,
----glands,
---- processes,
Cineritious substance of
  the brain             16
Circulus iridis arteriosus224
Circumflexa   £mter,l265
femoris arteria c. exter^
----humeris Canteri. ? 93-
arteria,     iposteri.3
      . ossis ilii arteria, 263
Circumvolutions of brain 15
of cerebellum,
Circus arteriosus of
  Willis,
Clitoris,
Coats of the Eye,
Cochlea,
Cceliac artery,
Colic arteries,
----veins,
Colon,
____, absorbents of the 197
Columnx valvulx Vieus-
  senii,                 34
— carnex ofthe
228
170
 31
 61
247
251
252
119 
336
  heart,
Coinmissurx cerebri,
Commissura mollis of
  the optic thalami,
Communicans faciei,
  nervus,
Cord, Umbilical,
Cornea,
Cornua ammonis,
Cornua ofthe Ventri-
  cles of the  brain,
Coronary vessels of heart, 99    lidochus,
----artery of the lips,   218  Duodenum,
       of stomach,
page.                     page.
   93 Dartos,               151
   21 Depressor oculi,        44
      Diaphragm, Blood-ves-
   18   sels of the
      ----, nerves of the
  287 Dorsal nerves,
   177  Drum of the ear,
   31 Duct cystic,
   20 ----■, hepatic,
      ----, pancreatic,
   17 Ductus communis cho-
246
314
319
 56
136
134
140

136
117
 10
Corpora albicantia,
----cavernosa penis,
— fimbriata,or Tceni
  Hyppocampi,
Corpora olivaria,
       pyramidalia,
247 Dura mater,
 24 ----, blood-vessels of
 157    the            13—234
            processes of the 11
Corpus adiposum,        9
----callosum,          15
---- ciliare,            35
----mucosum,          4
Corpus spongiosum ure-
  thrx,               158
Cortical substance of
  brain,
Costal nerves,
Cranium, nerves which
  pass through the base
  of the               281
Cricoid cartilage,       78

Crura  ^cereJ,,r}|. ~l
       £ cerebelli, y
Crystalline lens,
Cutaneous nerve of the
  superior extremity,
Cuticle,
Cutis vera,
Cystic artery,
Cystis fellis-,
20 Ear, of the
 26----, small bones of the
 ib ----, muscles proper to
the
  -, external
  —, internal
  —, muscles ofthe
 53
 59

 53
 52
 56
 53
292
    Eighth pair of nerves,
    Emi   Colivares     "
        .."  <mammillares
 16 nent,*>flpyramidale. .
319 Emulgent artery and
      vein,
    Epidermis,
    Epididymis,
    Epigastric artery,
 „5 Epiglottis,
    Ergot, or hippocampus
 38   minor,
    Eustachian tube,
307 Extre-(  superioi
  3 niity, I  inferior
  5 Eye, ofthe              27
248 ------, coats ofthe     51
135 —.----,  humours of the  33
255
  3
152
261
 78
infe
18
57 
337
Eyes, vessels of the      45
Eye and its appendages,
  arteries ofthe       222
------, veins of the    230
———, muscles of the   43
Face,lymphatics of the 205
----blood-vessels ofthe 228
----nerves of the      290
Falx, or septum cerebri,  12
.----minor,  or septum
  cerebelli,
Fat,
Femoral  artery,
■       vein,
.       or crural nerve
Fibular artery,
------ vein,
 12
  9
265
275
270
271
275
273
------nerve,
Fifth pair of nerves, or
  partrigeminnm,      283
First pair of nerves, or ol-
  factory,             281
Follicles, sebaceous      8
Fornix,                 19
Fossa, or rima magna, 170
Fossa navicularis,        ib
----Sylvii,             19
Fourth pair of Nerves, or
  pathetic,           282
Frxnum  lingux,         61
----labiorum pudendi, 170
----preputii,          157
Gall-bladder,          135
Ganglia,               279
Ganglion semilunare
  magnum             321
Gastric arteries,        246
------ veins,          251
Generation and Urine
  Organs of       242,194
——, lymphatics of    193
r-—, blood-vessels of   2J5
                     page.
----, nerves ofthe     324
Gland, lacrymal,        29
------, parotid,        72
------, pineal,         22
------, pictuitary,      21
------, prostate,       155
Gland, sublingual,      73
----, submaxillary,      ib.
Glands, ary tenoid,      80
----, axilliary,         205
----, bronchial,        106
----, conglobate,       190
----, Hiac,             194
----, inguinal,         192
   ., lumbar,          ib.
----, mesenteric,       196
----, miliary,            8
----, politeal,          194
----, renal,            146
----, salivary,          72
----, sebaceous,        29
----, tracheal,         106
Glandulx ceruminosx,  55
------concatenatx,    206
        Meibomian*,    29
odoriferx,
159.171
    159
    170
Glans penis,
----clitorodis,
Glosso-pharyngeus, ner. 293
Glottis,                 68
Gluteal artery,         26"!
—— nerves,         272
Gravid Uterus, of the   173
Gula, or gullet,         108
Gums,                  68
Gustatorius, nervus,     287*
Gutturalis, C superior,   217
  arteria,  c inferior    235
Gyri ofthe Cochlea,     61
Hxmorrhoi- C media, ?
dalis urteri, ([eater, y  263
—— vena, interna, '<  252 
338
Hairs,
Head, lymphatics on
  the outside,
----, blood-vessels of
  the
Heart, ofthe
page.                     page.
    7 ----of the cochlea,     62
      —— of the kidneys,    145
  205 Integuments, common,    3
      Intercostal arteries and
216
 89
veins,
   nerves,
Heart, absorbents ofthe 202 Intestines,
Hellicis,  $mi°J>l
       '  tmjnor,5
Helix,
Hemispheres of the
  brain,
Hepatic arteries,
------veins,
     absorbents of
Iris,
Isthumus hepatis,
----faucium,
     Vieursenii,
147
319
 95
195
 32
 31
 75
 92
247 Iter quartium ventriculum 2
254 ----quartum
 20 Jugular vein external,
    ----internal,
    Kidneys,
 91 Labia pudendi,
    Labial artery,
Hippocampus major,
Hole between the right
  auricle and ventricle
  ofthe heart,
—— between the lateral
  ventricles of the brain, 20 Labyrinth of the ear,
Humeral artery,
----vein,
Hymen,
Hypogastric artery,
----vein,
----lymphatics,
----nerves,
Jejunum,
----lacteals of the
237 Lacrymal artery,
242 Lacteals,
172 Lactiferous ducts,
262 Lamina spiralis,
276 Larynx,
195 Laryngea superior, ar
324 Laxat or tympani,
 95 Leg, see inferior extr
196 Levator oculi,

 «6ment \ rotund a,} uteri'I65
    Ligaments ofthe liver, 130
    Ligamentum suspen-
175   sorium penis,       158
 59 Lingual artery  &vein,
Iliac ar. and veins, 257263  Liga- Cjata,
Ilium, intestinum,
Impregnation, changes
  produced in the ute-
  rine system  by
Incus
Inferior cava,
Inferior Extremity, lym
  phatics of the
— blood-vessels of
.----nerves of the
Infta-orbita. artery
Inft ndiblilum of brain,
 ib
229
234
145
170
218
 61
223
188
 84.
 63
 76
217
 60
 97
 44
276	218.239
----nerve,	287
192 Lips,	68
262 I ipior amnii,	180
325----nericardii,	89
220 Live'-,	129
i'7 ----Mmpbatics ofthe 12o" 
                    page.                     page.
Liver, blood-vessels ofthe     sels,                350
                  110.248        nerves,          ib
------nerves ofthe    321 Mesentery,            121
Lobes ofthe brain      15 Mesocolon,             ib
------of the liver,     130 Mesorectum,          122
Lobes of the lungs,    102 Metatarsal artery,     270
Locus niger crurum cer. 24 Modiolus,              62
Lumbar arteries,      260 Motores octriorum, or
----plexus of nerves,  327   third pair of nerves,  282
Lungs,               101 Mouth, of the          68
•—— lymphatics ofthe  201 Musculocutaneous nerve
----blood-vessels of         of the superior extre-
    the           106.215   mity,               308
----nerves ofthe     315 Nails,                  7
Malleus               58 Neck, blood-vessels of ,
Maramx               82   the             192.216
Mammary art. & veins, 244 ----nerves ofthe      304
——nerves,            ib Nerves,ofthe         274
Masseteric arteries,    220 ------cerebral,       2 80
•Motor  Cdura  Dura7 ma ------spinal,         304
M    'ipia  '"Pia  5 ter- Ninth pair of nerves,   294
Matrix,               163 Nipple, or papilla,      83
Maxillary artery, exter. 218 Noni  descendens ner-
----internal,          219   vus,                294
----vein,             229 Nose, ofthe            47
______nerve £8UP'    285 NymPh*» r     .     *71
       nerve, ^Jnf    2g6 0bliquug  r superior,?  45
Meatus auditorius extr. 54   oculi.   {.inferior, 5
------internus,        61 Obturator artery,      263
Median vein,          242 ■ - ■   ■ nerve,         328
------nerve,         310 Occipital artery,      219
Mediastinum,          87 ■----- vein,          229
Medulla oblongata,     25 OEsophageal arteries
..........spinalis,      299   and veins,          245
Medullary substance of         - nerves,        316
  the brain,            16 OEsophagus*        .'108
Membrana cellularis,    8 OEthmoida- C anter.  } goa
-----pupillaris,    32.182   lis arteria, ^poster.5
—----tympani,        56 Olfactory, or first pair
-       —secundarii,    65   of nerves,           231
Meningeal artery,     220 Omentum, or cawl,    123
Mesenteric blood-ves-      Opthalmic artery,     338 
Opthalmic vein,
       —nerve,
Optic, or second pair of nerves,

Orbiculare, os,
ORGANS of tlie senses,
■■■         of  urine and genera-
  tion in the male,
1          in the female,
    ■      lymphatics ofthe,
       ■   blood vessels ofthe
         ■ nerves of the
 340
933 Popliteal artery,
282 ■   -     vein,
281
27S
252
 36 Portte, vena,
261 Portio,$^ftis}of the 7th pair  288
Os Tinea,
Ova   >
Ovaria 5
Palate,
  ■    arches ofthe,
Paletrina inferior arteria,
Palmaris profunda arteria,
Palmar arch, deep,
-----------superficial,
       ■ nerve,
  3 Prepuce ofthe penis,
   -------p ofthe clitoris,
142 Profunda femoris arteria,
163               -, vena
193    ■     humeri arteria,
255------- penis arteria,
315 Psalterium fbrnicis,
165 Pterygoideae arteri*
.„ Pudendum,
    Pudic artery,
 69 ——— vein,
 75 —— nerves,
218 Pulmonary artery and veins,
239 Pupil of the eye,
 ib. Pylorus,
240 Radial artery,
313    ■■-■  nerve,
 28 Ranina arteria,
139-------vena,
Palpebral
Pancreas,
Panniculus cavnosus,
Pap of the throat,
Papilla,
Papilla; of the tongue,
Par trigeminum, or fifth pair of    -------- radial artery,
  nerves                     283---------ulnar artery.
-5-,..   Cduct,  1                Renal artery and vein,
Parotid,  £ glan^ J              72------nerveSi
Pathetic, or fourth pairof nerves,282 Retina,
Pedes hippocampi,              20 Sacral artery,
Pedunculi of the brain and cere-    -----lateral arteries,
157
171
266
275
237
259
 20
219
109
258
260
325
214
 32
115
238
239
217
229
109
119
195
  bell urn,
Pelvis, lymphatics of the,
——, blood vessels of the
——, nerves ofthe
PENIS,
———, lymphatics *f the
———, blood vessels of the
——, nerves ofthe
Pericardium,
Perineum,
Peritoneum,
Peroneal  artery,
--------nerve,
Pharyngeal artery,
Pharynx,
Phrenic nerve,    *
Pia mater,
Pinguedo,
Placenta,
Plantar artery and arch,
Pleura,
Pontuin Adami,

Pons\ Varolii,.
10 Receptaculum chyli,
70 Rectum,
83 Rectum, lymphatics of the
71 Recurrent nerve ofthe 8th pair, 315
                                238
                                239
                                255
                                324
                                 36
                                260
                                263
                                271
                                 72
 25 —— nerves,
199 Salivary glands,

^ Saphana,vena,^]

157 Saphsenus, nervus,
194 Scala. £ t>'mP«ni' I
253 sca,a».l vestibuli, 5
325 Scapular arteries,
 88 ——— nerve
170 Sciatic artery,
111  ■      nerve,
271 Sclerotic coat,
273 Scrotum,
213 Sebaceous ducts,
 75 Second pair of nerves, or optic,
»274

  271

   62

  236
  307
  264
  272
   33
  150
    8 '
  247
il
314 Secundines,                   177
 14 Semicircular canals ofthe cochlea,63
  9 Semilunar ganglion,           321
178 Seminal vessels,               155
273 SENSES, organs ofthe          3
 85 Septum cerebri, or falx,         11
 77-------cerebelli,              12
           - lucidum,               19
           - penis,                158
25 
Seventh pair of nerves,
Sinuv-s-of dura mater, ■      J4,
Sixth pair of nerves,
Miiirf-skin,
Skin,
Spermsrtic artery and vein,
Spermatic cord,
►—.-----nerves,
Spincter vesicae,
SPINAL MARROW, of the
        nerves, origin ofthe
    70
   206
   218
   286
    75
13, 231
    IS
Spiral nerve,
Splanchnicus nervus,
SPLEEN,
------•-, lymphatics ofthe
Splenic artery,
317,
  Spongiosum, corpus, urethra*,
  Stapedius,
  Stapesy
  Stomach,
    >*    , absorbents of the* 116,
  —|----, blood vessels of   115,
        ■', nerves ofthe     116,
  Sublingual artery,
  Submental iirtery,  (
  Suboccipii al nerves,
  Superlms,
  Supercilia,
  Superior cava,
  SUPERIOR EXTREMITY,
  -------, lymphatics ofthe
  -------, blood vessels of
         , nerves of the
  Supra-orbitar artery,
  Taenia h ippocampi,
  -----semicircularis of Haller,
  Tarsea arteria,
  Tarsus of the eye-lids,
  Tela choroides,
  Temporal artery,
  —-----vein,
  Tensor tympani.
  Tentorium cerebelli,
  Testes,
  —— lymphatics ofthe
  —— blood vessels of      153
  ■i     nerves of the
. Thalami nervorum opticorum,
' Third pair of nerves, or motorcs
   oculorum,
tjThoracie duct,             92,
Thorax, of the
          -, blood-vessels within
          -, nerves within the
 341

288 Tibial arteries*                 2(39
233----veins,                    273
288---- nerve,                    331
  3 Tomentum cerebri,
  5 TONGUE, ofthe
256----, lymphatics of the
153----, blood-vessels of
324 ——, nerves of the
149 Tonsils,
299 Torcular HeropMli,
 ib  Traetus optici,
309 Tragicus,                      *4
321 Tragus',                        52
137 Tricuspid valve,                °3
200 TrosJilearis,                    45
249 Tuber annulare,                2*
251 Tubercula quadrigemina,        22
322 Tuberculum Lonveri,            °2
158 Tubes, Eustachian,              57
 f>0----, FaUo/rian,                166
 59 Tunica albuginea,              1*1
113----- arachnoidea,              14
198------arariea, or vitrea,         42
247------chorpidet,                34
321----- scelerotica,               33
217 —— vaginalis,               151
218 Tympanum,                    56
304 Vagina,                       167
 44 Vaginal artery,                 258
 28 Valves ofthe absorbents,        190
246 ---- ofthe veins,               213
    —— of heart and arteries        93
208 Valvula coli,                   127
235 Vasa brevia,              248,  252
304----efferentia ofthe testes,     154
224      C efferentia 7 of absor-     191
 19   ~" £ inferential bents,


 28 Vasa vasorum,                  209
 20 VEINS, ofthe                 212
221 Velum Vieussenii,               22
228 Vena cava, general coarse of
 60--------, superior,
 12--------, inferior,
215
246
276
260
253
 17
 91
  THROAT, ofthe
I^Th>Toidea arteria  jj"^
150 Vena magna ipsius penis,
194 Vena portae,
254 Ventr.cles ofthe brain,
32S    '     of the heart,
 18 Vermiform appendix of the coe-
      cum,                        127
282 Vesica urinaria,           147,  162
200 Vesicalis ima arteria,           26*4
 81 Vesicula fellis,                 13S
244 Vestible ofthe labyrinth,        61
314         of the pudendum,      171
 75 VISCERA, ofthe               3
235 Vitreous humour,               41
217 
                              342

Ulnar arteries,                238 Ureters,                  146.163
---nerve,                   311 Urethra,                  159, 171
Umbilical cord,               177 UTERUS, ofthe             163
■-------artery,               257-------, appendage* Of       ' 165
Volar arches,                 241 Uvula,                        70
Vorticose veins,               230 Zonula ciliaris.                 12
FINIS. 
 
 
KeA-Hist.
   U/2.
  5.70
 F117CO
  l?IO