518 C. A. LAUBACH, J. L. RICE AND W. W. FORD 



clave but are destroyed by 12 pounds pressure. In the Arnold 

 they survive 30 minutes steaming but are destroyed by one 

 hour's exposure. 



MISCELLANEOUS CULTURES 



BY WILLIAM W. FORD 



On a number of occasions miscellaneous cultures from a va- 

 riety of sources have been studied with care and identified. 

 Such cultures, about 100 in number, include spore-bearing organ- 

 isms found at times as laboratory contaminations, in the normal 

 and abnormal dejecta of children and adults, in milk products, etc. 

 The majority of such cultures were easily identified and found 

 to correspond to the well-known types already described. The 

 most frequent isolation was Bacillus cereus which is our common 

 laboratory contamination. Next to this organism Bacillus suh- 

 tilis was most frequent, then Bacillus vulgatus or Bacillus mesen- 

 tericus. Members of the Megatherium-petasites group were 

 also not uncommon. In addition to such isolations as these 

 Bacillus circulans of Jordan was found on one occasion. It is 

 recognized by its cylindrical terminal spores and by its cultural 

 reactions. Dr. Jordan was kind enough to examine the culture 

 and confirmed our identification. Bacillus circulans is evidently 

 one of the rarer sporulating bacteria. At another time a round- 

 spored organism resembling Bacillus tetani in morphology was 

 encountered as a contamination on an old agar plate. This spe- 

 cies was apparently first described by Kruse (Fliigge, 1896) as 

 an aerobic variety of the tetanus bacillus. On three occasions an 

 organism was isolated which was originally obtained by Fliigge 

 (1894) and named later Bacillus brevis by Migula (1900). The same 

 species was found by us in Montreal. Finally on one instance a 

 culture was found in the normal dejecta which could not be iden- 

 tified with any previously described organisms. The morphology 

 and spore formation were so characteristic and so different from 

 that seen with other spore-bearing bacteria that it was decided to 

 create a new species for which the name Bacillus centrosporus is 

 selected. A detailed description of these organisms follows. 



