no THE GROUSE DISEASE chap. 



of resisting those tests generally considered indica- 

 tive of the presence of spores. Simple but thorough 

 drying in a thin film kills all bacilli ; exposure to a 

 temperature of 60° C. for ten minutes sterilises the 

 bacilli completely. Numerous experiments were 

 made in this direction ; the result was in all cases 

 uniform. While heating to 60° C. for five minutes 

 was not reliable, heating to 60° C. for ten minutes 

 in all instances killed the bacilli. 



From recent and old broth, gelatine, and Agar 

 cultures numerous inoculations were made into gela- 

 tine and into alkaline broth in tubes ; these were then 

 exposed to 60° C. for ten minutes, placed in the incuba- 

 tor, the first at 20° C, the latter at 35-37° C, but they 

 all remained sterile. Broth cultures from twenty-four 

 hours to three weeks old, and gelatine cultures from 

 one to six weeks old, were tested for the vitality of the 

 bacilli by establishing sub-cultures from them, then ex- 

 posing the original cultures to 60° C. for ten minutes. 

 After this sub-cultures were again made. While the 

 sub-cultures made from the original culture before heat- 

 ing proved successful, the sub-cultures made from the 

 heated original culture remained sterile. It follows 

 then from these experiments that there Is no evidence 

 that the bacillus of fowl enteritis is capable of forming 

 spores. 



2. Does one mild attack of fowl enteritis protect a 



