332 JACK J. HINMAN, JR., AND MAX LEVINE 



face and butt) and incubate the latter for 72 hours observing daily. 

 If pure, a transparent growth with acid on slant and acid and gas in 

 butt will be observed. If non-fermenting spore-formers are present 

 the surface growth becomes opaque. Microscopic examination of 

 Gram's stain of 48 to 72 hour culture on lactose (Andrade) agar 

 should show no spores. If spores were present, then the purifica- 

 tion process outlined above was repeated, for it was observed that 

 whenever this was the case, a non-fermenting aerobic spore former 

 could be isolated while the pure fermenting type did not show spores 

 on this medium in the designated time . The strains isolated resemble 

 B. macerans described by Schardinger. 



MORPHOLOGY 



Vegetative cells. The organism varies in size on different culture 

 media. 



On nutrient agar, the vegetative cells appear (after 24 hours at 37C.) as 

 rods about as wide as B. coli, but 2 to 4 times as long. The size of the majority 

 being 0.6 by 2.5 /x. They are grouped singly or in pairs; parallel forms were 

 frequently observed and occasionally V forms were noted. The ends are 

 rounded and the bacillus is slightly fusiform. 



On lactose (Andrade) agar and in litmus milk the cells are somewhat longer, 

 usually 3 1 o 4 n . Spores were not seen . 



In lactose (Andrade) broth they appeared especially elongated often 

 measuring 6 and occasionally 8 AC. All of the 14 cultures showed an occasional 

 spore on nutrient agar after 24 hours and after 48 hours at 37, sporangia and 

 spores were numerous. The endospores are elliptical, their diameter greater 

 than that of the vegetative cells and located sub terminally. The size of the 

 majority of spores was 0.8 by 1 .4 /*. 



STAINING REACTIONS 



After repeated observations and comparison with known cultures 

 the organisms were considered to be Gram negative. This was 

 particularly true if the cultures were grown on lactose media. The 

 gentian violet stain is removed with difficulty and the Gram stain 

 may easily be confused. The technique employed was to stain for 

 1J minutes with aniline oil gentian violet then with Gram's iodine, 

 to decolorize for 5 minutes with fresh 95 per cent alcohol and to 

 counter-stain with dilute saffranin. 



The Gram stain showed the vegetative cells to exhibit a tendency 

 to granulation but in cultures from agar and Loeffler's blood serum 



