2 3 6 



E. G. SPAULDING. 



EXPERIMENT V., 1-450 n HC1. 



, 6o Q 5 IQ IS 10 If 30 y 40 4ffSOW't>0' 6f 70' 7<f' $0 



fcammliCt 



30', followed by a second rise and a second fall respectively 

 before and during segmentation. This fall is repeated at the 

 beginning of the second cleavage. 



Comparison of this with the ' ether curve ' however shows a 

 difference in respect to this 'thirty-minute fall/ and that this 

 should be so is to be expected from the possibility of the agent 

 here used (HC1) directly affecting the colloidal particles as well 

 chemically as electrically, as the evidence for a specific H ion 

 action indeed indicates ; while in the case of ether the solvent 

 alone is first concerned. 



Assuming that the H ions in some way penetrate the egg, the 

 increase in osmotic pressure resulting therefrom might be con- 

 nected with the dissolution of the nuclear membrane, which 

 occurs at about the time of the first, the 30' fall, 1 in such a way 

 that an abnormal increase in pressure results from both, which 

 inhibits development. This however could not be due alone to 

 the electronic action of the ions for were this so ether also 



i Mathews and Wilson, lac. cit.; cited by Lyon. 



