SPERM FILTRATES AND DIALYZATES. 3! I 



separation of the parts and their ultimate cytolysis. In a very 

 few cases a slightly elevated membrane is visible. These results 

 were reproduced with different lots of eggs and with different 

 filtrates and dialyzates. In no case did these changes occur in 

 sea-water controls or in sea-water filtered or dialyzed. The 

 latter results indicate that no substance is given off by the 

 filters or collodion sacs that can account for the effects of sperm 

 filtrates and dialyzates. 



i a j 



t * "J 10 II U 13 If IS" It '? I* I 1 ) ao 



GRAPH I. The percentage of ova divided and cytolyzed by sperm nitrates of 

 the same species Arbacia punctulala. A = the average of ten experiments with 

 nitrates made from 2 per cent, suspensions. B = the average of ten sea-water 

 controls. = percentages in individual experiments with sperm nitrates. 



Confirmation of these results was obtained in a series of forty- 

 two experiments with filtrates and twenty-four experiments with 

 dialyzates. Within twenty-four hours the majority of ova in 

 the test solutions had undergone decided changes, while those in 



