NO N- PATHOGENIC BACTERIA. 273 



Bacillus Erythrosporus. Found in decomposing fluids 

 and water; a slim bacillus with rounded ends; motile; does not 

 liquefy gelatin; facultative anaerobic; forms oval, red-colored 

 spores, two to eight in each filament; grows rapidly, only at 

 ordinary temperatures; produces a greenish-yellow, fluorescent 

 pigment. On potato it forms a limited, reddish growth be- 

 coming nut-brown. 



Bacillus Cyanogenus (Bacterium syncyanum; Bacillus 

 lactis cyanogenus; Bacillus of blue milk). A bacillus of vari- 

 able size, with rounded ends; motile; spore formation doubtful; 

 is aerobic; not stained by Gram's method; grows rapidly at 

 ordinary but not so well at incubator temperatures on the usual 

 culture-media; does not liquefy gelatin; produces a grayish- 

 blue pigment, brighter in acid media, at ordinary tempera- 

 tures; milk is not coagulated or rendered acid. 



Bacillus Acidi Lactici (Hueppe). Found in sour milk; a 

 short, plump rod; not motile; does not liquefy gelatin; facul- 

 tative anaerobic; grows on the ordinary media; in milk causes 

 development of lactic acid with precipitation of casein and 

 production of gas and alcohol. It belongs in the same group 

 as B. coli communis and B. lactis aerogenes (see Part IV.). 



There are numerous other bacteria, such as the Bacterium 

 acidi lactici, which cause the formation of lactic acid in milk. 



Heinemann,* as the result of his studies, comes to the con- 

 clusion that it is not justifiable to regard B. acidi lactici as a 

 specific bacillus. 



Bacterium Ureae. A short, thick bacillus with rounded 

 ends; not motile; aerobic; found in ammoniacal urine; grows 

 slowly at room temperature upon gelatin, which is not lique- 

 fied; decomposes urea; forms ammonium carbonate. 



Bacterium Zopfii. Found in the intestines of hens, in 

 water and in fecal matter; a bacillus 0.75 to i Abroad and 2 to 5 

 A* long; may form threads. Actively motile; does not liquefy 



*Heinemann. Jour. In}. Diseases. Vol. III., p. 173. 

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