194 COLLECTED STUDIES IN IMMUNITY. 



stood when the high degree of amboceptor concentration in immune 

 sera is considered. In my case larger amounts of guinea-pig serum 

 must be avoided, because in large doses the guinea-pig serum by 

 itself finally exerts a toxic action on guinea-pig spermatozoa. This 

 agrees with a statement of London (1. c.) that most all normal sera 

 contain autospermo toxins. 



SUBSEQUENT NOTE. In the meantime the French translation of a study by 

 London, which had already been published in Russian, has appeared (Contribu- 

 tion a I'e'tude des spermolysines, Archives des Sciences Biologiques, T. IX, 1902), 

 which shows that this investigator had also already recognized the complex con- 

 stitution of the normal spermotoxin. 



Our views concerning the complex nature of haemoylsins have recently been 

 confirmed by Flexner and Noguchi through the successful separation of am- 

 boceptor and complement in the cold (Snake venom in relation to haemolysis, 

 bacteriolysis, and toxicity, Journal of Experimental Medicine, vol. VI, 1902). 



