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MATSUZIRO TAKENOUCHI 



and normal guinea-pig serum (2) was conducted in the following 

 manner (table 9). 



As is indicated in table 9, we can activate the hemolysin in 

 the antiserum by using the normal guinea-pig serum as comple- 

 ment, while normal rat serum cannot do this, even when a 

 double amount is used. We conclude, therefore, that the normal 

 complement of rat serum cannot be used for activation (comple- 

 mentation) of the hemolysin against rat corpuscles obtained 

 from the rabbit, and this is certainly not because of its quantity, 

 but because of the quality of the normal rat complement. We 

 can make this statement because, according to Kolmer, Yui and 

 Tyau ('13), the activity of the gray rat complement in activating 

 the antihuman amboceptor is about one-third that of the guinea- 

 pig complement, and the activity of albino rat complement is a 

 little stronger, being on the average about half that of guinea-pig 

 complement. 



The negative hemolysis in the case of the normal rat serum 

 used for complement may therefore be due to the presence of 

 either, 1) some anti-amboceptor in the rat serum, or 2) of some 

 anticomplementary substance, or to both of these factors. 



1 The reading was made after one hour of incubation and six hours in the 

 ice-box. 



