SPIRILLA RESEMBLING CHOLERA. 291 



In puncture-cultures the development takes place along 

 the entire puncture, and causes a gradual liquefaction of 

 the gelatin. 



Upon agar-agar the growth is generally similar to that 

 of the cholera spirillum, but at times is copious, dry, 

 and' ragged, and suggests leather by its appearance. 



When introduced intraperitoneally into guinea-pigs 

 the animals die in from one to two days. 



The indol reaction is exactly like that given by cul- 

 tures of the cholera spirillum. The spirillum does not 

 stain by Gram's method. 



Spirillum Dunbar. This organism (Fig. 89) was de- 



FIG. 89. Spirillum Dunbar, from agar-agar; x 1000 (Itzerott and Niemann). 



scribed in 1893 by Dunbar and Oergel, who secured it 

 from the water of the Elbe River. It much resembles 

 the cholera spirillum, but it never exhibits sigmoid forms. 

 It stains poorly, the ends taking the color much better 

 than the central portion. 



Gelatin is liquefied by the growth of this organism 

 more quickly than by the cholera spirillum. The colo- 

 nies upon gelatin and the puncture-cultures in gelatin 

 are identical with those of the cholera spirillum. 



On agar-agar a luxuriant whitish-yellow layer is pro- 

 duced. 



