642 



COLLECTED STUDIES IX IMMUNITY. 



TABLE XIII. 



After this the fluid decanted from the tubes of series A are mixed each 

 with 0.5 cc. inactive ox serum, and the fluids from series B, each with 0.5 cc. 

 salt solution. The mixtures are then digested each with the sediments from 

 1 cc. 5% strongly prepared ox blood. 



In control series C made at the same time, mixtures containing each 0.5 cc. 

 inactive ox serum plus decreasing amounts of horse serum were digested at 

 37 for two hours, after which strongly prepared ox blood was added. 



The result of the experiment is shown in the following table: 



TABLE XIV. 



Amount of 



Hsemolysis of Ice. 5% Strongly Prepared Ox Blood. 



From the table it is clearly apparent that in the digestion with 

 weakly prepared ox blood, the horse complement remains entirely 

 intact provided plenty of ox serum is present, whereas by itself it 

 is bound by the prepared blood, as can be seen from Column A. 

 The evidence presented by this marked difference becomes still 

 stronger through the fact that the action of mixtures of horse serum 

 and ox serum on weakly prepared blood results in a slight degree of 



