426 



MARIE A. HINRICHS. 



they do ripe eggs. The retention of considerable activity by ad- 

 sorbed fertilizin suggests its enzyme-like nature. Such behavior 

 has been noted for pepsin by Kikawa, '23. Richards and Wood- 

 ward, '15, and Lillie. '21, have ascribed an enzyme-like nature to 

 fertilizin. 



When ripe unfertilized eggs are added to a charcoal- fertilizin 

 system, and then fresh sperm are added, the sperm show a pref- 

 erence for the eggs, rather than for the bits of charcoal. The con- 

 centration of active fertilizin is probably greater about the egg- 

 surface due to continued production of fresh fertilizin by the egg. 



It was possible to recover a small amount of the adsorbed ferti- 

 lizin by washing the charcoal with slightly acidified sea water. 

 (See Table VII.) Glaser, '2ib, reports the recovery of some 

 fertilizin by HC1. Neither iso-amyl alcohol nor saponin were 

 effective in displacing the fertilizin from adsorption. 



TABLE VII. 



THE RECOVERY OF FERTILIZIN ADSORBED ON CHARCOAL. 



HC1 was used.) 



\\ hen a charcoal-fertilizin system is washed with sea-water, the 

 nitrate will be found to activate but not to agglutinate sperm. 

 Apparently the activating substance is not adsorbed to the same 

 degree as are the other substances in egg-water. 



There seems to be an optimum pH range for the adsorption for 

 fertilizin by charcoal, as well as for its effectiveness as a sperm- 

 agglutinating agent. This optimum pH range, like that found by 

 Clowes and Smith for fertilization, hovers around neutrality. 

 ( See Clowes and Smith, '22, '23, Smith and Clowes, '24, a, b, c.) 



