352 Illinois IState Laboratory of Natural History. 



Table I. 



Source op Infection. 



NUMBEB OP Deaths. 



2 

 days. 



3 



days. 



days. 



10 

 days. 



Total. 



Number 

 of bugs 

 remain- 



These experiments further demoustrate the effective- 

 ness of the isolated bacillus, and they also indicate that 

 fresh cultures are more active than old ones. The tube 

 used in l-^xpeiiment 10 was inoculated the previous day 

 from the tube subsequently used in Experiment 9. This 

 series would also indicate that fresh cultures are as 

 effective for infection as infusions direct from diseased 

 insects. From general observations, however, I should 

 judge that the most effective infection material is from 

 insects recently dead. Experiment 12 is difhculb to ex- 

 plain, since a culture from this same grasshopper seemed 



* This insect was probably a spent individual of the first brood, and not diseased, as 

 the post-mortem characters were not at all indicative of disease. 



