STUDIES ON H.EMOLYSINS. 



103 



TABLE VI. 



This shows that 0.2 cc. of the anti-immune body are able to com- 

 pletely inhibit the action of 1.8 times the solvent dose of immune 

 body as determined by the control test, and that it almost neutral- 

 izes the action of five times such a dose. If, however, we measure 

 the protective power by comparing the complete solvent doses in 

 the two cases, this appears much stronger. The ratio of the com- 

 plete solvent doses in the presence of immune body and in the control 

 test is then 1:17.5. We shall discuss the reason for this later. 



Since the inactive rabbit serum employed in immunization con- 

 tained complementoids, the presence of anticomplements along with 

 the anti-immune body is easily understood. The anticomplements at 

 first were directed against rabbit serum. After the immunization 

 had continued for some time longer anticomplements appeared 

 directed against certain complements of guinea-pig serum. In these 

 experiments, therefore, in order to overcome the anticomplement 

 action (in reality insignificant) directed against the reactivating 

 guinea-pig serum, it was merely necessary to employ a considerable 

 excess of the latter. 



In contrast to these results are those obtained in an analogous 

 series of experiments, in which, however, the complement was in the 

 jorm of goat serum instead of guinea-pig serum. (See Table Via.) 



