QUALITATIVE BACTERIOLOGICAL ANALYSIS. 47 



The other cultural reactions corresponded to those already 

 given under the B. fluorescens non-liquefaciens. The colour 

 produced in gelatine, broth and agar was bright green. 



B. Fluorescens Aureus. 



This bacillus was also isolated by Zimmermann from the 

 Chemnitz water supply. It has the following cultural charac- 

 teristics. 



Colonies in Gelatine Plates. The colonies in the depth appear 

 as small yellowish-white dots; the surface colonies are yellowish- 

 grey, smooth, not sharply outlined expansions ; they are darker 

 in the centre and delicately streaked at the margin. The 

 gelatine is not liquefied. 



Gelatine-stab. A. thin yellowish layer, which later becomes 

 thicker in the centre, appears on the surface, and in eight to ten 

 days reaches the margin of the gelatine. In the stab there is 

 very little growth, which later becomes brownish in colour. 



Gelatine-streak. It produces a thick ochre-yellow growth, 

 under which the gelatine acquires a marked brown colour. In 

 transmitted light the gelatine appears greenish-yellow. 



Agar-slope. A rich ochre or golden-yellow growth ; the 

 agar becomes darker but does not fluoresce. 



Potato. The growth is the same as on agar. 



Gas-production. Not observed. 



Microscopical Appearance. A short bacillus with rounded 

 ends, about twice as long as broad, found in pairs, rarely in 

 greater numbers. It is very motile. It produces a yellow-ochre 

 pigment, and stains faintly with Gram. 



A culture of this organism from Krai's laboratory produced 

 colonies exactly like those described above. On potato and 

 agar the growth had a yellow-ochre colour. The growth 

 in gelatine was yellowish, and the gelatine acquired a green 

 fluorescence. The microbe did not coagulate milk, produce 

 indol, nor form gas in glucose-gelatine. 



B. Fluorescens Crassus. 



This microbe is described byFliigge in "Die Mikroorganismen." 

 The colonies are very granular in the depth of the gelatine ; 

 on the surface they are round, slightly opaque, and have a 



