296 INFECTION AND IMMUNITY. 



serum is used. Most normal serums show a 

 greater or less degree of toxic action for the sper- 

 matozoa of other animals, and normal spermotox- 

 ins like the immune consist of amboceptor and 

 complement. Metchnikoff claims to have pro- 

 duced an autospermotoxin by immunizing guinea- 

 pigs with the spermatozoa of other guinea-pigs. 



When a spermotoxic serum is injected into the 

 living animal it is thought that the amboceptors 

 are taken up by the homologous cells, and this 

 would seem to affect the vitality of the sperma- 

 tozoa, inasmuch as De Leslie rendered male mice 

 sterile for 16 to 20 days by the injection of the 

 serum. 



It is of theoretical interest that castrated ani- 

 mals will yield spermotoxin by immunization, 

 showing that the amboceptors are not of necessity 

 produced by the analogous tissue of the immun- 

 ized animal. From the fact that spermotoxic 

 serums are hemolytic, it is assumed that certain 

 receptors are common to erythrocytes and sperma- 

 tozoa. Hemolytic serums, on the other hand, may 

 not be spermotoxic. There is nothing contradic- 

 tory in this lack of reciprocal action, for those re- 

 ceptors which are common to the two cells may not 

 be important for the life of the spermatozoon, 

 whereas the opposite condition prevails with the 

 erythrocyte. 



It is certainly of interest that immunization with 

 the plasma of ova causes the formation of spermo- 

 toxic amboceptors, a fact which points to certain 

 common constituents of the two cells. 



Antispermotoxin may be produced by immuniza- 

 tion with spermotoxic serum (anticomplement or 

 anti amboceptor) . 



