DIGESTION 45 



. It is exceedingly probable that the purpose of pro- 

 tein digestion is the reduction of these complex mole- 

 cules to the form of crystalline products, the amino 

 acids. Putrefaction is also concerned with these sub- 

 stances forming from them compounds which may 

 exert perhaps at times a more or less deleterious 

 action as, for example, indole or skatole, but also trans- 

 forming the amino acids into products, as tyramine or 

 histamine, which time may show to have distinct physi- 

 ological activities in keeping normal the adjustment 

 of nutritional rhythm. 



REFERENCES TO LITERATURE 



Barger: The Simpler Natural Bases. 1914. 



Cathcart: Physiology of Protein Metabolism. [Digestion.] 



Hammarsten: Text Book of Physiological Chemistry. 1914. 

 [Digestion.] 



London: Handbuch der Biochemie. Oppenheimer. III. 1909. 

 [Digestion.] 



Rettger: Journal of Biological Chemistry. 1915, 20, p. 445. 

 [Putrefaction of pure proteins.] 



Schaefer: Text Book of Physiology. 1898. [Digestion.] 



Underhill: Middleton Goldsmith Lecture for 1911. Archives 

 of Internal Medicine. 1911, 8, p. 356. [Putrefaction.] 



Winterstein and Trier: Die Alkaloide. 1910. 



