AEROBIC SPORE-BEARING NON-PATHOGENIC BACTERIA 495 



cipal feature distinguishing B. ruminatus from Bacillus mega- 

 therium, which it most closely resembles. The species described 

 originally by Vogel (1897) as Bacillus mesentericus panis viscosi I, 

 now known as Bacillus panis Migula was found once; and one 

 isolation proved to be a new species belonging to the mycoides 

 group to which we have given the name Bacillus adhaerens. 

 The above list of organisms found in dust must therefore be 

 supplemented by the following types whose descriptions are 

 given below in full. 



Bacillus prausnitzii Trevisan 4 



{Bacillus ramosus liquefaciens Flijgge.) 



Bacillus mesentericus variety fiavus nov. var 2 



Bacillus ruminatus Gottheil 1 



Bacillus panis Migula 1 



(Bacillus mesentericus panis viscosi 1 Vogel.) 



Bacillus adhaerens, nov. sp * 



^■^'^Bacillus prausnitzii Trevisan 



This organism was originally described as Bacillus ramosus 

 liquefaciens by Flugge. It is sometimes regarded as identical 

 with Bacillus mycoides but a culture obtained from the Krai 

 collection in Vienna shows different reactions from those of 

 Bacillus mycoides. Several cultures corresponding closely to 

 the Krai culture were isolated from dust. The following de- 

 scription applies to the Krai culture and to our own isolations, 

 as well. 



Morphology. In young cultures 6 hours old on plain agar the 

 organisms are homogeneous, have round ends when free and 

 flattened ends when in juxtaposition. They generally occur in 

 chains of 2 to 4 elements and resemble Bacillus mycoides in mor- 

 phology. The single cells measure 0.625 to 0.75 by 3 to 5 mi- 

 crons. On glucose agar they are thicker measuring 0.75 to 1 

 by 3 to 5 microns. In older cultures, 24 hours, on both plain 

 and glucose agar the protoplasm is converted into globular 

 bodies which take the stain badly. These are especially abun- 

 dant on glucose agar which also shows long and thick vegetative 

 rods measuring 0.75 to 1 by 4 to 6 microns and peculiar washed- 



