THE METABOLISM OF EGGS, I 



6l 



than I, suggests that the increased respiration at the onset of the 

 meiotic divisions is not merely what might be expected in a divid- 

 ing cell, but that breakdown of the germinal vesicle is the re- 

 sponsible factor. This latter point is confirmed by the experiments 



TABLE II 

 The ratio (O2 uptake, fertilized eggs)/{02 uptake, unfertilized eggs) 



in various organisms 



of Borei (1948) on the eggs of Marthasterias glacialis (Linn.) in 

 which respiration increases during the breakdown of the germinal 

 vesicle and the meiotic divisions. In the case of the latter, the in- 

 crease persists after the meiotic divisions are completed. Cleland 

 (1950a) also found a difference in the respiration of oyster eggs, 

 before and after the breakdown of the germinal vesicle. 



