﻿302 STRONG. 



was found to be practically unchanged. The details of all the passages 

 are given in Series 28 which follows. The monkeys employed were 

 all of small size. The cultures were made from the animal, from 

 one and one-half to twenty-four hours after the time of the inoculation. 

 In a few instances in which the quantity of inoculated bacteria was large, 

 pus formation about the point of injection was found to have occurred 

 on incising the skin from twenty-one to twenty-four hours after the 

 time of the infection of the animal. However, the organisms in the 

 pus did not prove infectious when inoculated into guinea pigs in a con- 

 siderable amount. 



Therefore, my attempts to increase the virulence of a very virulent 

 pest strain or to reclaim that of a more attenuated one have been entirely 

 unsuccessful, the organisms in each instance having retained a very 

 stable virulence throughout. 



