SECT. 9] 



PROTEIN METABOLISM 



1061 



arginine distinctly falling. Sendju himself attached no special im- 

 portance to these variations, which would agree with those found 

 by Plimmer & Lowndes in the case of histidine and lysine, but not 

 in that of arginine. 



The best work on this subject is that of Calvery who made a com- 

 parative study of histidine, arginine and lysine, using a variety of 

 different methods.^ His figures, which are given in Table 132, show, 

 as regards the histidine (percentage of total nitrogen of whole egg. 



Arginine 



Days-* 5 



Days-»-5 

 Fig. 297. 



shell included), in one case no change, in another case a slight in- 

 crease, and in four cases, a definite decrease. Calvery regards Sendju's 

 increase as due to errors of technique, but thinks Russo's decrease 

 was genuine. As regards arginine, all four methods showed no 

 change. Sendju's diminution is again considered by Calvery as being 

 due simply to analytical errors, but no explanation is available for 

 the large fall found by Russo. Out of three methods used for lysine, 

 one showed no change and two a decrease, which Calvery thought 



1 Calvery's later work confirmed Sendju's fall in tyrosine and cystine but showed no 

 fall in tryptophane. 



