be designated as the differential opsonic index . 



The following data are intended to show the results of 

 opsonic determinations made by taking into consideration the 

 white count of the infected animals. Both the Wright and 

 differential opsonic indices are given. 



** Differential Opsonic Index. ^Average counts compiled from re- 

 sults obtained in this laboratory, supplemented by the counts of 

 Klieneberger and Carl (42). 



