624 NON-PATHOGENIC BACILLI. 



248. BACILLUS FLUORESCENS PUTIDUS (Flugge). 



Found in water. 



Morphology. Short bacilli with round ends. 



Biological Characters. An aerobic, non-liquefying, actively motile, 

 chromogenic bacillus. Produces a greenish, fluorescent pigment. Does not 

 form spores. Grows in the usual culture media at the room temperature. 

 Upon gelatin plates the superficial colonies are small, and under a low power 

 they are seen to be finely granular discs with a dark centre surrounded by 

 a yellow zone, and a pale-gray margin which is serpentine in outline; older 

 colonies are dentate and have a greenish shimmer ; the gelatin around ac- 

 quires a fluorescent green color ; an odor of trimethylamin is given off. In 

 gelatin stick cultures development occurs upon the surface only, as a thin, 

 dirty- white layer ; in the course of a few days the gelatin commences to 

 acquire a greenish, fluorescent color, most intense near the surface and 

 gradually fading out below. Upon potato a thin, slimy, gray or brownish 

 layer is developed. 



249. BACILLUS ERYTHROSPORUS (Eidam). 



Found in water, in putrefying flesh infusion, etc. 



Morphology. Slender bacilli with round ends ; often grow out into short 

 filaments. 



Biological Characters. An aerobic, non-liquefying, motile, chromo- 

 genic bacillus. Forms a greenish-yellow, fluorescent pigment. Forms oval 

 spores from two to eight in each filament. Grows at the room temperature 

 in the usual culture media not in the incubating oven. Upon gelatin plates 

 forms whitish colonies, which spread out over the surface of the gelatin as a 

 wrinkled and furrowed layer, around which the gelatin acquires a greenish- 

 yellow, fluorescent color; under a low power the colonies are seen to have an 

 opaque, brownish centre surrounded by a transparent, greenish-yellow mar- 

 ginal zone, an irregular outline, and the surface is marked by indistinct, ra- 

 diating lines. In gelatin stick cultures an abundant growth occurs along 

 the line of puncture and upon the surface ; the gelatin throughout gradually 

 acquires a fluorescent green color by transmitted, and a yellow color by re- 

 flected light. Upon potato a layer of limited dimensions is formed, which is 

 at first reddish in color and later nut-brown . 



250. BACILLUS VIRIDIS PALLESCENS (Frick). 



Morphology. Bacilli which are somewhat longer and more slender than 

 the typhoid bacillus ; form long filaments. 



Biological Characters. An aerobic, non-liquefying, actively motile, 

 chromogenic bacillus. Produces, in presence of oxygen, a pale bluish-green 

 pigment, which later becomes yellowish-brown with a green fluorescence. 

 Grows best at the room temperature. Spore formation not observed. Upon 

 gelatin plates the deep colonies are small and spherical; superficial colonies 

 flat, with irregular, well-defined margins and a granular surface similar to 

 Bacillus virescens, but larger and of more rapid development ; the colonies are 

 green in color at first, but fade out to a pale bluish-green ; they are fre- 

 quently slightly iridescent. In gelatin stick cultures growth occurs upon 

 the surface only, of a green color which quickly fades out to a bluish-green. 

 Upon the surface of agar the growth is the same as on gelatin. Upon potato 

 a nut-brown, moist layer is formed, and the potato around it acquires a dirty- 

 violet color. 



251. BACILLUS VIRESCENS (Frick). 



Found in green sputum. 



Morphology. Bacilli of about the size of the typhoid bacillus, three to 

 four times as long as broad ; frequently grow out iiito long filaments. 



