CULTIVATION OF THE BACILLUS 77 



human type. On this medium our strains of Johne's 

 bacilli usually grew, but only to a slight extent, and 

 the medium proved to be quite unsuitable for practical 

 purposes. 



From the fact that since the remotest times the 

 timothy-grass bacillus {Bacillus phlei Moeller) found 

 on Phleum pratense must have been continually in- 

 gested by ruminants in their food, the possibility of 

 this bacillus being the wild ancestor from which Johne's 

 bacillus has arisen is at once obvious, and if such be 

 the case one might expect, from what has been already 

 said, that B. phlei would be a very suitable variety to 

 use in preparing the medium. To the Qgg medium, 

 therefore, this bacillus, grown on ordinary broth, was 

 added to replace the human tubercle bacillus, J to i per 

 cent, of the dried bacillus being used. Johne's bacillus 

 on this medium grew quickly and well, the growth 

 being better than on any of the media so far tried. 

 A slight growth was visible along the needle-track 

 in one week, and in six weeks the growth closely 

 resembled that of a bovine tubercle bacillus freshly 

 isolated from the animal bod}^ 



In exactly the same way other acid-fast bacilli were 

 tested — i,e.^ incorporated, when dead and dried, in 

 Dorset's egg medium. The following were experi- 

 mented with : 



1. The smegma bacillus of Moeller. 



2. The nasenschleim bacillus of Karlinski, 



3. The fish tubercle bacillus of Dubard. 



4. The butter bacillus of Rabinowitsch. 



5. Bacillus from urine, Marpmann. 



6. Pseudoperlsucht bacillus of Moeller. 



7. Bacillus from butter, Grassberger. 



8. Three of the Tobler group of acid-fast bacilli; 

 Tobler, I., IV., and VI., Krai. 



