BACTERICIDAL ACTION OF NORMAL SERUM 199 



REMOVAL or BACTERICIDAL ACTION BY HETEEOLOGOUS 



BACTERIA 



In this series of experiments the methods are the same as 

 in the previous, with the single difference that the bacterium 

 to whose absorbing properties the serum is exposed, is 

 different from that on which the bactericidal action is subse- 

 quently tested. The following are examples : 



EXAMPLE 1. Inoculation with 0-0001 c.c. 24-hour bouillon 

 culture of B. dysenteries (Flexner). 



Result. Distinct reduction of bactericidal action with 0-1 c.c. of 

 dead bouillon culture ; other experiments with 0-01 c.c. gave nega- 

 tive results. 



EXAMPLE 2. Inoculation with 0-00006 c.c. 24:-hour bouillon 

 culture of B. typhosus. 



Result. Slight reduction by 0-01 c.c. of heterologous culture, 

 marked reduction by 0-1 c.c. 



