990 ENERGETICS AND ENERGY-SOURCES [pt. iii 



that a loss of protein had certainly taken place. Parnas & Krasinska 

 found no loss of fat during this time. Faure-Fremiet & Dragoiu also 

 studied the frog's egg; they agreed with Bialascewicz & Mincovna 

 in finding a loss of protein before hatching, but they also observed a 

 loss of glycogen and of fat, indicating that all three substances had 

 acted as sources of energy. 



1 1 . The same conclusion was arrived at by Farkas for the egg of 

 the silkworm, Bombyx mori. 



12. Dakin & Dakin found a utilisation of proteins during the 

 development of the eggs of the plaice, and Greene observed the same 

 thing in the king-salmon. 



13. If urea and uric acid are indicators of protein metabolism, so 

 also is the phenomenon of specific dynamic action. We have already 

 seen evidence that there is a period in the development of the chick 

 when this phenomenon appears (p. 935). Gayda's work on the heat 

 given out by toad embryos throughout their development, showed 

 that the heat eliminated during periods in which the weight was 

 doubled, plotted against the time, gave a curve with a peak in the 

 centre, to which the values rose and from which they descended. 

 Thus development was more economical at the beginning and end of 

 development than at the middle, just as in the chick. 



14. Pigorini's work on the embryos of Bombyx mori, in which the 

 glycogen was estimated throughout their development, fell into line 

 with the other researches on carbohydrate utilisation mentioned 

 above, and confirmed the older work of Vaney & Conte. The last- 

 named investigators found that not only glycogen but also fat fell 

 during the development of the silkworm. 



15. The only work which has been done on the chemical con- 

 stitution of the echinoderm egg during its development fits in well 

 with the high respiratory quotients found for the beginning. Ephrussi 

 & Rapkine found a fall in protein, fat and carbohydrate during its 

 development. 



16. In the chapter on respiration and heat production, attention 

 was drawn to the fact that Meyerhof's calorific quotients, obtained 

 during the early development of the echinoderm egg, did not corre- 

 spond with the theoretical values, either for carbohydrate, protein, 

 or fat combustion. Shearer's later values, which were based on a 

 rather greater heat production, came nearer, and finally Rogers & 

 Cole, finding still more heat, gave data from which calorific quotients 



