6 5 4 A N A T 
f.u are filled with a fine membrane. Inftead of a great 
’lumber of glandulae vagae to be found in the human me. 
jfentery, we find the glands few in number, and thofe are 
cloiely connedled together; or there is only one large 
gland to be obierved in the middle of the rriefentery of a 
dog, which from its imagined refemblance to the pancreas 
and the name of its difcoverers, is called pancreas AfelLii ; 
but the refemblance, if there is any, depends chielly on 
the connection, the ftrudture being entirely different. The' 
reafon why this in man is as it were fubdivided into many 
fmaller ones, may poilibly be, that as the guts of a hu¬ 
man body are proportionally much longer than thofe of 
tin's creature, it would have been inconvenient to have ga¬ 
thered all the laEleals primi generis into one place; where¬ 
as, by collecting a few of thefe veffels into a neighbour¬ 
ing gland, the fame effect is procured much more eafily. 
Whether the food in this animal needs lefs preparation in 
its paffage through thefe glands, is a matter very much 
unknown to us; though it is certain that fome changes 
really take place. 
The pancreas in man lies acrofs the abdomen, tied down 
by the peritonaeum; but, the capacity of this creature’s 
abdomen not allowing of that fituation, it isdifpofed more 
longitudinally, being tied to the duodenum, which it ac¬ 
companies for fome way. Its duft enters the duodenum 
about an inch and a half below the duCtus communis. 
The Jpleen of this animal differs very much from ours 
both in figure and fituation. It is much more oblong and 
thin, and lies more according to the length of the abdo¬ 
men, like the pancreas. Though the fpleen of this crea¬ 
ture is not firmly tied to the diaphragm (which was neceff 
tfary in our eredt pofture to hinder it from falling down¬ 
wards), yet by the animal’s prone pofition, its pofterior 
parts being rather higher than the anterior, it comes to be 
always contiguous to this mufcle, and is as cftedtually 
fr.bjedted to an alternate preffure from its adtion as the 
human fpleen is. 
The human Liver has no fiffures or aivifions, unlefs we 
reckon that fmall one between the two pylce, where the 
large veffels enter : whereas in a dog, and all other crea¬ 
tures that have a large flexion in their fpine, as lions, leo¬ 
pards, cats, &c. the liver and lungs are divided into a great 
many lobes by deep fedtions, reaching the large blood- 
veflels, which in great motions of the back-bone may ea- 
iilv lap over one another; and are thus in much lefs danger 
of being tern orbruiled, than if they were formed of one 
entire piece, as we really fee it is in horfes, cows, and fuch 
creatures as have their back-bone ftiff and immoveable. 
There is no ligamenium latum connedting the liver to the 
diaphragm, which in our fituation was neceffary to keep 
the vifeus in its place : whereas, in this creature, it natu¬ 
rally gravitates forwards, and by the horizontal pofition 
of the animal is in no danger of prefling againft the vena 
cava; the preventing of which is one ufe generally align¬ 
ed to this ligament in man. Had the liver of the dog 
been thus connedted to the diaphragm, the refpiration 
muff neceffarily have fuffered; for this mufcle is here 
moveable at the centre as well as at the tides.. But in 
man the liver is fixed to the diaphragm, moftly at its ten¬ 
dinous part; that is, where the pericardium is fixed to it 
on the other fide ; fo that it is in no danger of impeding 
the refpiration, being fufpended by the mediaftinum and 
bones of the thorax. In confequence of this vifeus being 
divided into lb many lobes, it follows, that the hepatic 
dudts cannot poffibly join into one common trunk till they 
are quite out of the fubftance of the liver; becaufe a 
branch comes out from every lobe of the liver; all of 
which, by their union, form the hepatic duct: whence 
we are led to conclude, that the hepato-cyftic dudts, men¬ 
tioned by former authors, do not exift. The gall-bladder 
it fo]f is wanting in feveral animals, fuch as the deer, the 
horfe, the afs, &c. but in place of it, in fuch animals, the 
hepatic duct, at its beginning, is widened into a refervoir 
of confiderable fize, which may anfvver the fame purpofe 
in them that the gall-bladder does in others. 
O M Y. [Comparative. 
The kidneys in this animal are fituated much in the fame 
way as in the human fubjedt; but have no fat on their in¬ 
ferior furface, where they face the abdomen, and are of a 
more globular form than the human. The reafon of thefe 
differences will eafily appear, if we compare their fitua¬ 
tion and pofiure with thofe in a man, who walks eredt. 
They are placed in this fubjedt in the inferior part of the 
body, fo are not fubjedt to the preffure of the vifeera, 
which feems to be the principal caufe of the-fatnefs of 
thofe organs in us, and perhaps may likewife be the caule 
of our being more fubjedt to the done than other animals. 
Hence there is no need of any cellular fubftance to ward 
off this preffure where there would neceffarily be fat col- 
ledted; but the fuperior part of their kidneys is fome- 
what covered with fat, left they ftiould fuffer any com- 
preflion from the adtion of the ribs and fpine. 
In the internal ftrudture there is ftill a more confidera¬ 
ble difference : for the papilla: do not here fend out Angle 
the feveral tubuli uriniferi ; but, being all united, they 
hang dowm in form of a ioofe pendulous flap in the mid¬ 
dle of the pelvis, and form a kind of feptum medium; fb 
that a dog has a pelvis formed within the fubftance of tlie 
kidney. Tlie only thing that is properly analogous to a 
pelvis in man, is that fac or dilatation of the ureters form¬ 
ed at the union of the duclus uriniferi. Tlie external part 
of the kidney of a dog fomewhat refembles one of the 
lobes of tlie kidney of a human foetus: but in a human 
adult the appearance is very different; becaufe, in man, 
from the continual preffure of the furrounding vifeera, 
the lobes, which in the foetus are quite diftindt and fepa- 
rated, concrete, but the original cortical fubftance is ftill 
preferved in the internal parts of the kidney. The rea- 
fon of thefe particularities may probably be, that the li¬ 
quors of this animal, as of all thofe of the carnivorous 
kind, being much more acrid than thofe of fuch as live 
on vegetable food, its urine muft incline much to an alka- 
lefcency, as indeed the fmell and tafte of that liquor in 
dogs, cats, leopards, &c. evidently fhew, being fetid and 
pungent, and therefore not convenient to be long retained 
in the body. For this end it was proper, that the fecern- 
ing organs ftiould have as little impediment as polfible by 
preffure, &c. in the performing their fundtions; and for 
that defign the mechanifm of their kidneys feems to be 
excellently adapted. 
The glandulce or capfulce atrabiliarice are thicker and 
rounder than the human, for the fame reafon as the kid¬ 
neys; and the ureters are more mufcular than the human, 
becaufe of tlie unfavourable paffage the urine has through 
them ; they enter the bladder near its fundus. The blad¬ 
der differs confiderably from the human; and firft in its 
form, which is pretty much pyramidal or pyriform. This 
ftiape of tlie dog’s bladder is likewife common to all qua¬ 
drupeds, except the ape and thofe of an eredt pofture. 
In men it is by no means pyriform, but lias" a large fac at 
its pofterior and inferior part: this form depends entirely 
on the urine gravitating in our eredt pofture to its bottom, 
which it will endeavour to protrude; but, as it cannot 
yield before, being contiguous to the os pubis, it will na¬ 
turally ftretch out where there is the leaft reliftance, that 
is, at the pofterior and lateral parts; and, were it not for 
this fac, we could not fo readily come at the bladder to 
extradt the ftone either by the Idler or lateral operation of 
lithotomy. Moil anatomifts have delineated this wrong; 
fo much, that none havejuftly painted it, excepting Cow- 
per in his Myotomia, and Mr. Butty. It has certainly 
been from obferving it in brutes and young children, that 
they have been led into this miftake. 
As to its conne&ion, it is faftened to the abdominal muff 
cles by.a procefs of the peritonaeum, and that membrane 
is extended quite over it; whereas in us its fuperior and 
pofterior parts are only covered by it: hence in man alone 
tlie high operation of lithotomy can be performed without 
hazard of opening tlie cavity of the abdomen. Had the 
peritonaeum been fpread over the bladder in its whole ex¬ 
tent, the weight of the vifcera in our eredt pofture w ould 
3 liftve 
