SECT. 9] 



PROTEIN METABOLISM 



1 107 



It was further found that the excretion was almost equally divided 

 between urea and ammonia, as can be seen by the diagram at the 

 top of Fig. 337. Bialascewicz & Mincovna noted that, while the loss 

 in dry weight up to hatching was 0-076 mgm. per embryo, the loss 

 in protein nitrogen was 0-012 mgm. per embryo or of protein 

 0-075 mgm. ; — they were inclined to hold, therefore, that before hatch- 

 ing only minimal amounts of fat and carbohydrate could be combusted. 

 Other investigators, however, have not agreed with this conclusion 

 (see p. 1 175). The 0-075 mgm. of protein disappearing would roughly 



O Bialascewicz fie Mincovna 

 * Barth^lcmy &i. Bonnet 



Hatching time between 



these limits according 



temperature 



Fig. 336. 



150 200 250 300 



Fig. 337. 



correspond with the 0-0039 c.c. of oxygen which was found by 

 Bialascewicz & Bledovski to be taken up by one from embryo between 

 fertilisation and hatching. 



Barthelemy & Bonnet found, as has been stated above, that one 

 egg of Rana temporaria contained 0-187 mgm. nitrogen without its 

 mucilaginous envelope, and 0-241 with it, while at hatching one 

 embryo contained 0-139 mgm. nitrogen. This was a loss of 25-7 per 

 cent, analogous to the loss of 23-1 per cent, found by Faure-Fremiet 

 & Dragoiu up to the end of the free-swimming yolk-provided 

 stage. But the point on which Barthelemy & Bonnet laid stress was 

 that, no matter what the temperature and therefore the rapidity of 



