33 2 PHYSIOLOGICAL CHEMISTRY 



There is still considerable confusion of terms when different authori- 

 ties discuss milk proteins and the action of milk curdling enzymes upon 



FIG. 105. . FTG. 106. 



FIG. 105. CURD OF HUMAN MILK 5 MINUTES AFTER INGESTION OF 75 c.c. MILK. 

 (Beginning of curd formation, ^ actual size). 1 



FIG. 105. CURD OF HUMAN MILK 10 MINUTES AFTER INGESTION OF 75 c.c. MILK. 

 (Maximum curd formation, ^ actual size). 1 



them. The English scientists 2 quite uniformly call the principal pro- 

 tein of milk caseinogen whereas the insoluble curd formed by rennin is 



FIG. 107. FIG. 1 08. 



FIG. 107. CURD OF Cow's MILK REGURGITATED 10 MINUTES AFTER INGESTION OF 

 500 c.c. WHOLE MILK. (Curds % actual size). 3 



FIG. 108. CURD OF Cow's MILK REGURGITATED 25 MINUTES AFTER INGESTION OF 

 500 c.c. WHOLE MILK. (Curds % actual size). 3 



FIGS. 105 TO 108. PHOTOGRAPHS REPRESENTING TYPICAL CURDS FROM HUMAN AND 



Cow's MILK. 



termed casein. On the other hand, the Germans and many Americans 

 give the name casein to the milk protein and paracasein to the product 



1 Unpublished photographs from the thesis of Dr. Robert A. Lichtenthaeler. 



2 Halliburton: Journal of Physiology, n, 448, 1900. 



3 Bergeim, Evvard, Rehfuss and Hawk : Am. Jour. Physiol., 48, 411, 1919. 



