413 
J[. With a fleshy or gelatinous envelope, in- 
testines hollow, and adhering in the mass 
of the body. —Urticaria, [' 
III. Very small, swimming in fluids. — Infu- 
soria. . , , , 
IV. Gelatinous bodies, increasing by buds. 
— Polypi. 
B Attached to a solid trunk. 
V. In which the medullary substance crosses 
a corneous axis, and terminates in polypi 
on its branches. — Zoophyta. 
VI. In which each polypus is inclosed in a 
horny or calcareous shell, and is not con- 
nected by a medullary axis. — Eschar a. 
VII. In which a solid axis is covered with a 
sentient flesh, from cavities in which the 
polypi issue. — Cevatophyta. 
VI II. In which a stony axis or base serves 
for the receptacle of the polypi. — Litho- 
plujki. . , . . , 
IX. In which the base is spongy, friable, or 
composed of fibres. — Spongia. 
ANATOMY OF A COW. 
Class 1st, order 2d, genus 8th, species iu- 
minantia. 
Postal state. 
For the production of the foetus in this ani- 
mal, as well as in the human species, some- 
thing is necessarily derived from the ovaria. 
The uterus of the cow has large cornua, in 
which a portion of the secundines is contain- 
ed; consisting principally of the allantois, 
with the contained liquor. r l he muscular 
fibres of the uterus are plainly marked. 
Upon its internal surface are found a number 
of glandular bodies, which are formed by the 
termination of the uterine vessels. When 
the womb is in an impregnated state, a kind 
of mucilaginous liquor may be pressed out 
of these glandular bodies, these aie called 
the papilla? of the uterus. The mouth of the 
womb (os uteri) is entirely closed by a mu- 
cilaginous substance, that is common to the 
females of all animals when in a state of preg- 
nancy. The first of the proper membranes 
of the foetus is the chorion ; on the external 
surface of which are spread a number of 
fleshy bodies, called cotyledones, or placen- 
tube, which answer the same purpose with 
the placenta in the human subject. These, 
though indented among the papillae, have no 
vascular connection with them. 
The allantois, or allantoides, is the second 
membrane of the uterus. 1 his is extremely 
fine and transparent; it is not an entire 
involucrum of the foetus, but is chiefly 
lodged in the cornua uteri. In mares, bitches, 
and rabbits, it envelopes the amnios. In 
sheep and goats, the form and comparative 
extent of this membrane, are nearly the same 
as in the animal we are now describing, 
while in swine and in rabbits it covers still 
less of the amnios. A quantity of urine is 
commonly found in the sac, which this mem- 
brane forms, probably by the dilatation of 
the urachus, which is connected at its othei 
extremity to the fundus of the bladder. r l his 
membrane is exceedingly vascular ; its ex- 
istence in the human female has been a sub- 
ject of much dispute. See Midwifery. 
The third proper involucrum of the foetus 
is the amnios. This membrane is thinner 
and firmer than the chorion. Ramifications 
of the umbilical arteries and veins are spread 
45 ut upon it, by the terminations of which, 
COMPARATIVE ANATOMY. 
at its lateral parts, a liquor is secreted into 
the cavity ot the membrane. 1 Ins liquor is., 
in the first instance, in a small quantity ; it 
afterwards increases; and agaim towards the 
end of pregnancy, decreases. I he amnios 
does not enter the cornua uteri. 
We And in the foetus of this animal two 
vena? umbilicales, the circulation ot which is 
performed in the following manner. I he 
blood from the placenta of the mother is con- 
veyed into the capsula glissoniana, where it 
becomes blended with the blood of the vena 
porlarum. Part of this blood proceeds im- 
mediately to the cava by the ductus veno- 
sus; the rest circulates 'through the liver. 
The whole is transmitted from the cava into 
the right auricle, whence part is sent by the 
foramen ovale into the left auricle: the rest 
passes directly into the pulmonary artery, 
through the right ventricle. A small portion 
of this last circulates through the lungs, while 
the greater part is conveyed immediately 
from the pulmonary artery' through the me- 
dium of the canalis arteriosus into the de- 
scending aorta. 
Adult state.. 
There are no dentes incisorcs in the upper 
jaw of this animal; but the gums are hard, 
and the tongue remarkably rough ; its sub- 
stai ce being covered by long sharp-pointed 
pap ill £T, which are turned towards the throat, 
for the purpose of "retaining the recei ved ali- 
ment. The oesophagus of this animal is com- 
posed of a double row of spiral libres, which 
decussate each other. In common with all 
the ruminating animals, the cow has more 
than one stomach. Some of the ruminantia 
have two, some three ; while the subject 
u der examination has four stomachs, or ra- 
ther ventricles; the first of these is the lar- 
gest ; it is vulgarly called the paunch ; this lies 
upon the left side, and immediately receives 
the aliment. Upon the internal surface of 
this ventricle, there are a great number of 
small blunted processes, which give the whole 
a general roughness and considerable extent. 
By the force ot flic muscular coat of the 
paunch, aided by the gastric hquors, the 
food is in this cavity Sufficiently macerated; 
after which it is returned through the (eso- 
phagus into the mouth, where it is now mas- 
ticated. T his process is what is called chew- 
ing the cud, or rumination. After rumination 
the food is sent down into the second sto- 
mach, into which the oesophagus opens di- 
rectly, as well as into the first. This second 
stomach is smaller than the first; it is situat- 
ed anteriorly : the cells on its internal sur- 
face cause it to assume the appearance ot a 
honeycomb. Here the food is further ma- 
cerated, and is hence protruded into the 
third ; the interior surface of which forms a 
number of plicae or folds ; from this stomach 
it passes into the fourth, the structure and 
function of which greatly resemble the hu- 
man stomach. This perhaps ought, in strict 
propriety, to be alone denominated the sto- 
mach. It is worthy of remark, that in con- 
sequence of the elaboration ot the aliment in 
ruminating animals, much less food is re- 
quired by them than by others, who have 
only one stomach. In the horse there is hut 
one ventricle for the maceration of the in- 
gesta, from which a liquor for nourishment 
is extracted, and the remainder discharged, 
by the anus, very little altered,. 
The intestinal canal of the cow is of con- 
siderable length ; there is scarcely any dif- 
ference in the diameters of the large and 
small guts. The caecum is capacious and 
long; the spleen is attached to the diaphragm; 
the liver is not divided into so many lobes as 
in man; the vesica urinaria is ot apyianndal 
shape; it is exceedingly capacious; the cor- 
nua of the uterus are contorted in the/ form 
of a snail ; the heart differs in form from that 
of man principally in having a more acute 
point, which point is composed only of the 
left ventricle; the aorta is properly, in this 
animal, divided into ascending and descend- 
ing. 
ANATOMY OF A DOMESTIC FOWL. 
Class 2d, genus 4th, species gallinse. 
I bis animal, like all others of the same 
class, is oviparous. The oesophagus of this 
creature passes down its neck, inclining some- 
what to the right side: it terminates in a 
large membranous sac, which is the ingluvies 
or crop, where the aliment is macerated and 
dissolved; then passing out, it proceeds down 
the remaining portion of the oesophagus into 
what has been called the ventriculus succen- 
tarius, formed by a continuation of the gullet, 
with more numerous glands. M hese glands 
separate a liquor, by which the tood is still 
more diluted, before it enters the true sto- 
mach, gizzard, or ventriculus callosus. 
The duodenum begins nearly at the same 
place where the oesophagus enters; the two 
orilices are however divided by means of a 
protuberance, called septum medium. The 
duodenum is chiefly situated in the right 
side; its two extremities are attached to the 
liver ; the ductus choledochus enters near its 
termination, and discharges its contents into 
the gut. contrary to the course of the food. 
The small intestines are of considerable 
length. At the termination of the ilia, there * 
are two large coecu, one on each side pro- 
ceeding in an ascending direction from the 
side of the rectum. The excretories of the 
urine have already been described, as dis- 
charging their contents into the cloaca. See 
general anatomy of the class aves. 
The pancreas lies between the two folds 
of the duodenum; the spleen sends its 
blood into the vena portarum; the liver is 
divided into two equal lobes by a pellucid 
membrane. The principal peculiarity to be» 
observed in the heart,- is the want of the val- 
vuke tricuspides, and their place being sup- 
plied by one fleshy substance : the form and 
mechanism of the lungs are the same as in 
the other genera of the class. Cells are found 
in every part of the body, which communi- 
cate with those of the lungs ; and, as before 
remarked, are filled with air, which even 
penetrates into the cavities ot the bones. r I lie 
trachea at its division is very much contract- 
ed. jUence, in part, the shrillness of voice 
peculiar to this class of animals. That birds 
are without diaphragm has already been re- 
marked. In the animal we are now descri- 
bing, the whole thorax and abdomen are di- 
vided by a longitudinal membrane, or me- 
diastinum, attached to the lungs, pericar- 
dium, liver, stomach, and likewise covering 
the stomach and intestines ; this is analogous 
to the omentum in the human species. 
The lacteals pass from the intestines upon 
the mesenteric vessels; those of the. dike- 
