QUALITATIVE BACTERIOLOGICAL ANALYSIS. 45 



Potato. A greenish-yellow growth. 



Glucose-gelatine. No gas formation. 



Nitrate-broth. No reduction of nitrates. 



Milk. Unchanged. 



Peptone-water. No indol reaction. 



Litmus-whey. No formation of acid takes place. The 

 medium often becomes slightly alkaline. 



Microscopical Appearance. Short thin bacilli with rounded 

 ends ; as a rule not motile. It does not form spores. Optimum 

 temperature 21-25 C. ; it does not develop at 37 C. It does 

 not stain by Gram's method. The type above described cor- 

 responds to the B. fluorescens non-liquefaciens of Eisenberg, 

 B. fluorescens albus of Zimmermann arid B. aquatilis fluorescens 

 of Lustig. The Bacillus viridis pallescens isolated by Frick 

 form green sputum, and found by Tils in the Freiburg pipe- 

 water, differs from the type only in that the bacillus is highly 

 motile, and the growth on potato has a nut-brown colour. 



B. Fluorescens Longus. 



This variety of the B. fluorescens non-liquefaciens was isolated 

 by Zimmermann from the Chemnitz water-supply. Its charac- 

 teristics are as follows : 



Colonies on Gelatine Plates. The young colonies in the depth 

 are white dots with a greenish tinge. On the surface at first 

 they are thin, almost round, and have a mother-of-pearl 

 shimmer. They grow rapidly, have a greenish-yellow colour, 

 and look as if yellowish-white threads had been drawn through 

 them. Under a low power, the deep colonies are yellow, sharply 

 outlined with a convoluted interior ; the surface colonies show 

 a similar appearance, but the convolutions are broader and 

 resemble the convolutions of the intestine in a small animal. 



Gelatine-stab. Forms a thin expansion at first, but later 

 becomes thicker in the centre and soon reaches the margin of 

 the gelatine. At first the colour is blue, but later blue-green. 



Agar. A thin growth, and the agar becomes greenish- 

 yellow in colour. 



Potato. Forms a yellowish moist growth which rapidly 

 spreads over nearly the whole surface. 



Gas-production. Not observed . 



