ANATOMY OF THE CAT. 565 
The abdominal cavity contains the principal reproduc- 
tive, excretory, and digestive organs. The csophagus ter- 
minates in the stomach almost immediately below the dia- 
phragm. The stomach (JS?) occupies a transverse position, 
its larger (cardiac) end, which receives the esophagus, lying 
on the left, the smaller (pyloric) end on the right. The 
pylorus has a sphincter muscle which can completely close 
the orifice. The stomach is followed by the long intestines 
(Jn), most of which have been removed, leaving a short 
piece in front. The posterior portion of the intestine is 
somewhat dilated, is called the colon, and passes into 
the wide terminal rectum (Rec). The whole abdominal 
portion of the intestinal canal is suspended from the me- 
dian dorsal line by a thin membrane, the mesentery, which 
forms several folds, the most striking of which is the omen- 
tum or grand epiploon (Om.). This fold, when in situ, 
hangs down from the stomach like an apron, covering over 
the intestines ventrally. Upon opening the walls of the 
abdomen, it is the first structure met with. It usually con- 
tains a great deal of fat. Its principal function is supposed 
to be to prevent the loss of heat. The omentum is present in 
all mammals, but is least developed in Cetaceans, being most 
prominent in Carnivora and ruminants. Connected with 
the intestine are two glands, the liver (Zi) and pancreas. 
The liver is large and lies directly underneath the diaphragm. 
The elongated light-colored pancreas lies alongside the front 
end of the intestine (Jn), or so-called duodenum ; in its 
microscopic structure it resembles the salivary glands. The 
spleen is closely connected with the stomach, and is of an 
elongated shape, as in the majority of the Mammalia mono- 
delphia. 
The kidneys (47) are large and oval, and lie on either 
side of the vertebral column; the aorta passes between 
them, giving off a renal branch to each gland. A deli- 
cate ureter (Urt) passes from each kidney obliquely across 
the rectum to the large flask-shaped bladder (B7). A 
urethra (Ur) arises from the bladder posteriorly and 
