BACTERIOLOGICAL EXAMINATION OF WATER. 



result. The vibrio was then transmitted from culture to culture 

 for more than a year, but it retained unimpaired the cultural 

 characteristics just given. It failed to grow at 37 C., gave no 

 cholera-red reaction, and did not react with cholera serum in 

 vitro. These results are directly opposed to the statement of 

 Pfeiffer that a vibrio which does not react to cholera serum is 

 not a descendant of a true cholera vibrio. 



THE DIAGNOSIS OF THE CHOLERA Vnmio FROM 

 ALLIED FORMS. 



Many spirilla have been isolated from various sources which in 

 some of their cultural reactions closely resemble the true cholera 

 spirillum. The most important of these are the following : 



Spirillum of Finkler-Prior. 



This micro-organism was isolated at Bonn by Finkler and 

 Prior during an epidemic of cholera nostras. Koch asserted 

 that these observers had only found the microbe on one occasion ; 

 but, in a second paper on the same subject, Finkler and Prior 

 stated that they had isolated the vibrio from other cases of 

 cholera nostras in perfectly pure culture. The cultural charac- 

 teristics of the vibrio are as follows : 



Gelatine Plates. During the first stages of growth the colonies 

 are larger than those of the cholera spirillum, and show a smooth 

 circular margin free from crenations. In twenty-four hours the 

 gelatine commences to liquefy, and in forty-eight hours the 

 liquefaction is very marked, the colony which is now ragged and 

 torn lying in a circle of liquefaction. The double contour effect 

 seen in the case of the cholera colonies is little marked, as a large 

 clear area results from the rapid liquefaction of the gelatine. 



Gelatine-stab. In twenty-four hours there is distinct growth 

 along the line of inoculation, and at the upper part liquefaction 

 is commencing with the formation of an air bubble. In forty- 

 eight hours liquefaction has advanced considerably and produced 

 a funnel-shaped excavation with a deposit of bacteria at the 

 apex of the funnel. 



Agar-slope. The growth forms a moist, greyish-white layer,, 

 indistinguishable from that of the cholera vibrio. 



Potato. There is a growth at ordinary temperature con* 



