ORGANS OF DIGESTION 1 45 



bile is secreted faster than it is permitted to enter the intestine, 

 it passes backward from the common bile duct into the cyst. 



The bile aids in the absorption of the fats by the villi, and 

 renders the chyme alkaline. The formation of red blood- 

 corpuscles takes place in the liver of the embryo, while in the 

 adult, the liver destroys these corpuscles. The chief function 

 of this organ, however, is the formation of glycogen from the 

 sugars and starches eaten and the gradual transformation of 

 this glycogen into sugar as demanded for the nutrition of the 

 body. Diabetes mellitus is caused by a diseased liver or 

 pancreas which permits sugar to accumulate in the blood. 



The pancreas (Fig. 66) is an elongated gland bent at a 

 right angle near its middle. The body of it lies dorsal to the 

 pyloric portion of the stomach, and the head lies close along 

 the concavity of the duodenum. It has two ducts, one of 

 which enters the duodenum in common with the common bile 

 duct, while the other enters about three centimeters further 

 caudad. The pancreatic juice acts on the starches, proteids, 

 and fats. A pancreatic bladder is sometimes found in the 

 cat, although it has not been described for any other vertebrate. 

 It probably has its origin as an accessory pancreas in which 

 the terminal lobe has become dilated to form the bladder while 

 the proximal portion atrophies, leaving only the duct (Boyden). 

 Another theory is that the pancreatic bladder is split off from 

 the gall bladder primordinum. "Neither of the two theories 

 as to the cause of pancreatic bladders will explain all known 

 cases. Both theories must therefore be retained " (Bremer '23) . 



THE PERITONEUM 



The peritoneum (Fig. 67) is the serous sac lining the abdom- 

 inal cavity and investing most of the organs therein contained. 

 The four portions of the peritoneum are known as the omenta, 

 the mesenteries, parietes, and ligaments. 



The omenta are three in number, the largest of which is 

 the great or gastrocolic omentum, stretching caudad from the 



