The Digestive System. 55 



which in its turn liberates the fatty acids before men- 

 tioned. The organ secreting the abdominal saliva, as the 

 pancreatic juice has been called, is known as the pan- 

 creas ; it is of a reddish cream color, and is situated 

 behind the stomach and liver and in front of the kid- 

 neys. Its. duct (Wirsung's) joins that of the liver in 

 the horse, not in cattle and sheep. Pancreatic juice is a 

 colorless alkaline fluid of a varying conipositon, depend- 

 ing on the state of secretion. This juice contains a large 

 amount of solids and is readily decomposed, the process 

 being evidenced by the fecal odor. It contains four fer- 

 ments, one that acts on starch (amylolytic), one that acts 

 on proteids (proteolytic), a fat splitter (into fatty acids 

 and glycerine) and a milk curdling ferment, similar in 

 action to rennet. The first ferment converts starch into 

 sugar, thus duplicating the work of the saliva 5 it is, how- 

 ever, much stronger than ptyalin (the active principle 

 of saliva). The action of the second is similar to that of 

 pepsin (the active agent in gastric juice), differing only 

 that while pepsin needs an acid medium to work in, this 

 ferment, trypsin, requires an alkaline medium. Pan- 

 creatic rennet is more active than that of the stomach ; 

 boiling, however, destroys the power of the ferment. 

 The secretion of pancreatic juice is constant in the ani- 

 mals being dealt with (herbivora), and is at its maximum 

 towards the end of rumination. In addition to the se- 

 cretions mentioned, is that of certain glands (Lieberkuhn 

 and Brunner) of the intestines, known as intestinal juice 

 (succus entericus), which has an action similar to the 

 pancreatic juice. It is readily seen that intestinal di- 

 gestion is very important, owing to the complex nature 



