SPERM FILTRATES AND DIALYZATES. 



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that when sperm suspensions were heated to 5o-6o centigrade 

 the solutions failed to affect eggs. I therefore made filtrates 

 from suspensions of Arbacia sperm heated to 42-5O centigrade 

 to compare their action with those of filtrates from unheated 



10 



GRAPH V. Percentage of ova divided and cytolyzed by two similar filtrates of 

 sperm of the same species Arbacia. A -= Sperm nitrate 6/30/21 from a 5 per cent, 

 suspension. B = Sperm nitrate 7/2/21 from a 5 per cent, suspension. C = Sea- 

 water control. 



sperm suspensions. The spermatozoa lose their iso-agglutinable 

 and their fertilizing properties at a temperature of 38-4O 

 centigrade and tend to adhere to one another. One heated 

 suspension was first passed through filter paper and then through 

 a Mandler filter. As a control a part of the same suspension, 

 unheated, was similarly treated. A comparison of the effect of 

 the two filtrates is given in the following table. 



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