Organs of the Animal Body : their Forms and Uses. 39 
which they contain, and get back a similar bulk of new fluid 
about every twenty-four hours. But, like the air in the lungs, 
the fluid is never entirely good nor altogether bad ; it is con- 
stantly giving up its best materials, and as constantly getting 
back a mixture of good and bad. The good to be used for 
the support of the structures, and the bad to be excreted from 
the skin, kidneys, intestines, and other excretory organs, whose 
beneficent action is continuous, indeed cannot be interrupted for 
a short time even without damage to health, if not risk of life. 
Oegans of Digestion. 
Organs of Digestion. — To get the full benefit of the inquiry 
into the organism of the dead animal, which has served to 
illustrate the structure and uses of the breathing and circu- 
latory organs, it is now required that the abdominal cavity 
be opened, by cutting away the flank. The organs which will 
be exposed to view will vary, according to the kind of animal 
which is under examination, and the side on which the carcass 
is lying, and it will generally be the easiest plan to remove 
the stomach and intestines from the cavity in which they are 
lodged, and spread them out for inspection. 
In the ox and sheep the stomach forms, with its four 
divisions, the chief bulk of the digestive organs, the intestines 
being small in comparison. 
While the contents of the abdominal cavity are being re- 
moved, it will be noticed that the stomach is joined to a red 
tube, which is the gullet (oesophagus), running through the skirt 
(diaphragm), along the lower part of the neck above the wind- 
pipe to the back of the mouth, where it expands into a sort of 
funnel (pharynx). 
Returning to the abdomen, it will be noticed that the cavity 
and all the organs in it have a covering of smooth, moist mem- 
brane (peritoneum), which, in the form of folds, suspends the 
different organs and keep them within certain limits, one 
large fold, extending over a considerable part of the intestines, 
is seen at once, from the fact that it contains a good deal of 
fat, called flare ; this structure is known as the great omentum. 
Then a large fold of the membrane (mesentery) suspends the 
intestines from the spine, and along it all the vessels pass which 
go to and from the intestines. In the horse the stomach 
when cut from its attachments presents the form shown in 
Fig. 26, p. 40. 
The stomach of the pig bears a close resemblance to the 
stomach of the horse, but it is less curved on itself, and of 
course is smaller. 
