GENERAL ANATOMY OF THE MAMMALIAN BODY 
13 
which hangs posteriorly from the greater curvature of the stomach 
and is known as the great omentum. (Particularly well shown in 
the cat.) The spleen, which is not a part of the digestive system, 
is inclosed between the layers of the left hand portion of this 
structure; and the pancreas, an important digestive gland, which 
lies mainly between the layers of that portion of the mesentery 
which supports the first loop of the intestine, also pushes itself 
into the adjacent region of the omentum. Ventrally the stomach 
is suspended by a ventral mesentery, between the two layers of 
which the voluminous liver is located, so that one portion of the 
mesentery stretches between the stomach and the liver and is 
known as the lesser omentum, while the remaining portion 
stretches from the liver to the diaphragm and forms the falciform 
ligament. 
Look for a gall bladder (absent in some species) partly imbed¬ 
ded in the liver, and for a duct leading from this, or from the liver 
directly, to the first loop of the intestine into which it opens in 
close proximity to the opening of the pancreatic duct. 
Note the enormous length of the small intestine and compare it 
with the total length of body. The first loop, into which the 
stomach leads and the ducts from the liver and pancreas open, is 
known as the duodenum. Trace the small intestine posteriorly 
to the place where it opens into the side of the large intestine or 
colon. 
Note that the colon has a blind extension, the caecum, which is 
very wide and voluminous in the rodents (cf. cat and man). Do 
you find an appendix opening into this? Compare the total 
length of the colon with that of the small intestine. 
Remove and discard the entire abdominal portion of the 
digestive system leaving only a sufficient length of the rectum to 
serve as a landmark. 
4. The Urogenital System. (Cf. models showing relationships in 
the human body.) By exchanging specimens study both 
sexes, and record by means of a suitable drawing of each. 
The Urinary System. —Note the location of the kidneys dorsal 
to the parietal peritoneum and hence not actually in the abdomi¬ 
nal cavity. Look for the suprarenal gland slightly anterior to each 
