4 oo 



CHOLERA. 



recent agar culture in a guinea-pig, the amount sufficient to 

 cause death being also ascertained. The immunity test 

 should, of course, be employed, where this is possible. 



A number of other spirilla have been cultivated, which 

 are of interest on account of their points of resemblance to 

 the cholera organism, though probably they produce no 

 pathological conditions in the human subject. 



Metchnikoff's Spirillum (vibrio Metchnikovi). This 

 organism was obtained by Gamaleia from an epidemic 



disease 



of fowls 

 Odessa, and is 



special interest on 

 account of its close 

 resemblance to the 

 cholera organism. 

 In the natural dis- 



v . * Vjiv ease, which especially 



L^"fW affects young fowls, 

 the animals suffer from 

 diarrhoea, pass into a 

 sort of stupor, sitting 

 with their feathers 

 ruffled, and usually 

 die within forty -eight 

 FIG. 95- -Metchnikoff's spirillum, both hours> The intestines 



m curved and straight lorms ; from an agar 

 culture of twenty-four hours' growth. 



. . 

 Contain a grey IS h-y el- 



Stained with weak carbol-fuchsin. x 1000. low fluid, sometimes 



slightly blood-stained, 



in which the spirilla are found. A few of these spirilla 

 may also be found in the blood in the younger fowls, though 

 generally absent from the blood in the older. 



Morphologically the organism is practically identical with 

 Koch's spirillum (Fig. 95). It is actively motile, and has 

 the same staining reactions. Its growth in peptone-gelatine 

 also closely resembles that of the cholera organism, though 

 it produces liquefaction more rapidly (Fig. 96, A). In gelatine 

 plates the young colonies are, however, smoother and more 

 circular. After liquefaction occurs, some of the colonies 



