VIBRIOS IN WATER. 407 



by a sparkling crown. In stab-cultures the colonies, likewise, 

 display horizontal radiation. Gelatin is slowly liquefied. 



in. VIBRIOS. 



Since the great epidemic of cholera at Hamburg in the year 

 1892, a large number of vibrios more or less closely resembling 

 that of cholera have been described, which have been cultivated 

 in part from river-water, in part from other sources, and of 

 which the most important will be mentioned. 



35. Vibrio Aguatilis Gimther. This organism is scarcely to 

 be confounded with the comma-bacillus, on account of its cir- 

 cular, finely granular colonies, with smooth borders, even inde- 



K*v ^?' 



V _V 



-%! 



Fig. 88. Spirillum aquatilis, from an agar-agar culture ; X 1000 (Itzerott and 

 Niemann). 



pendently of the absence of the cholera-red reaction. It at 

 first grew feebly in liquid nutrient media, but as a result of re- 

 peated inoculation it acquired, in consequence of adaptation to 

 such media, the property of growing upon bouillon and peptone- 

 water. 



36. Vibrio Berolinensis. This organism, which was cultivated 

 by Neisser (1893) from the water-supply of Berlin, bears a close 

 resemblance to the cholera-bacillus in regard to form and 

 flagella. Upon gelatin-plates the border of the colonies is, 

 however, mostly smooth. The colonies themselves exhibit a 

 much more finely granular appearance than those of the comma- 

 bacillus. Gelatin is slowly liquefied, and the cholera-red reac- 



