52 Kansas Academy of Science. 



only in pancreatic digestion are also formed. The same sub- 

 stances as those formed in the action of tryptic digestion on 

 protein are formed in gastric digestion, and in consequence we 

 now look upon and ascribe to the gastric juice much greater 

 digestive importance, so far as the proteins are concerned, 

 than heretofore. 



Caseinase, rennin, rennet, lab-ferment, are names given to 

 the other important ferment found in the stomach which has 

 the power of curdling milk. 



The pepsin of Pekelharing, the purest and most potent ever 

 extracted, is able not only to act on proteins but also curdles 

 milk. Pepsin and rennin seem to be therefore parts of the 

 same molecule. This view was suggested by Nencki and Sie- 

 ber before him. A number of authors have pointed out the 

 fact that rennin always coexists with a proteolytic ferment. 

 In the human being and in certain other animals rennin ac- 

 companies the pepsin of the stomach and the trypsin of the 

 pancreas. Rennin also is found in largest amounts in those 

 portions of the stomach where the most pepsin is found, 

 namely, the fundus. 



