FERTILIZATION AND OXIDATION 



33 



TABLE III 



A determination of the temperature coefficient of oxida- 

 tions in the egg of Arbacia did not show such a variation. 



TABLE IV 



The temperature coefficients of oxidations for a difference 

 of 10 C. are practically identical throughout. For the interval 

 7-17 the coefficient is 2.0 and for 17-27 it is also 2.0. This 

 result points toward the probability that the rate of cell division 

 is not directly determined by the rate of oxidations, although 

 the possibility exists ttyat besides the influence of temperature 

 upon the velocity of chemical reactions an influence upon some 

 physical property of the egg is superposed (e.g., viscosity) 

 which makes itself felt only or chiefly at the lower temperatures 

 and becomes the stronger the lower the temperature. 



6. The writer has shown that segmentation and develop- 

 ment can go on only if the concentration of the HO ions in the 

 surrounding solution reaches a certain height; this height is 



