QUALITATIVE BACTERIOLOGICAL ANALYSIS. 127 



hours incubation, appear as thin white expansions, more or less 

 circular in outline, with granular contents ; later, the margin 

 becomes irregular, and wandering processes pass out in all 

 directions, slowly spreading over the gelatine. Zooglcea forms 

 are commonly seen. Gelatine is slowly liquefied. 



Gelatine-stab. On the surface there is a thin white growth, 

 from which processes run out to the margin ; along the stab 

 there is a white growth from which processes penetrate almost 

 horizontally into the surrounding gelatine. The gelatine is 

 very slow r ly liquefied. 



Gelatine-streak. There is a white growth along the line of 

 inoculation, from which processes run out to the margin, pro- 

 ducing a growth somewhat like a feather. The growth is very 

 like that of Proteus Zenkeri, but the processes are shorter and 

 thicker. The gelatine is slowly liquefied. 



A gar. A thin white growth. 



Potato. Greenish-yellow, moist, slightly raised growth. 



Glucose-gelatine. No gas formation. 



Mill:. Unchanged. 



Nitrate-broth. Nitrites and ammonia produced. 



Peptone and Salt Solution. Noindol reaction produced. 



Microscopical Characters. A motile bacillus ; often resembles 

 a coccus, and at times grows out to a length of 3 to 4 /LL. 

 Involution forms are common. 



Proteus Zopfl. 



A culture of this organism, which I obtained from Krai's 

 laboratory, gave reactions in the various media, closely 

 resembling the Proteus Zenkeri. The colonies in gelatine 

 plates showed the same beaded wandering processes. The 

 s warmers were, however, not quite so marked, and on gelatine 

 streaks the lateral processes were shorter and thicker, more 

 resembling Proteus mirabilis. 



All the varieties of Proteus when " plated " in 5 per cent, 

 gelatine show, after a few hours incubation and before lique- 

 faction has commenced, a peculiar motility of the bacilli. 



MICRO-ORGANISMS SUGGESTIVE OF SEWAGE CONTAMINATION. 

 The following organisms appear to be frequently present in 

 waters contaminated with sewage, but are rarely, if ever, found 



