96 PRINCIPLES OF PHYSIOLOGY 



and more soluble forms of protein called 

 peptones, and the mass, containing, in addition 

 to peptones, undigested protein matters, 

 sugars, starch-granules that have escaped 

 the action of the saliva, fats in a more or less 

 fluid state, salts in solution, constitutes 

 the chyme. It is doubtful if absorption 

 to any extent occurs in the stomach. The 

 free hydrochloric acid of the juice may 

 cause some proteins to swell and become 

 gelatinous-looking, forming what is called 

 syntonin. The acid also, to some extent, 

 destroys bacteria that are almost inevitably 

 swallowed with the food, but many escape 

 into the bowel. The gastric juice of young 

 mammals also contain rennin, a milk-curdling 

 enzyme. Thus the special action of the gastric 

 juice is on proteins. 



50. The Intestine. The chyme is propelled 

 into the small intestine, which is of great 

 length; in it two processes occur: (1) the 

 completion of digestion, and (2) the absorp- 

 tion of digested matters. Near the beginning 

 of the small intestine, in the duodenum, two 

 fluids mix with the chyme, the bile, formed 



