SPIRILLUM CHOLERA ASIATICM 



189 



in all artificial media, provided these are neutral or slightly 

 alkaline. 



Its growth on gelatin plates and stab-cultures is quite 

 characteristic. At the end of a few hours on gelatin plates 

 the colony appears as a light whitish point, which grows 

 very rapidly, liquefying slightly the gelatin around it. This 



FIG. 68. 



Stab-culture of the spirillum of Asiatic cholera in gelatin, at 18 to 20 C. : a, after 

 twenty-four hours; b, after forty-eight hours; e, after seventy-two hours; d, after 

 ninety-six hours. (Abbott.) 



liquefaction of the gelatin seems to be accompanied by 

 evaporation of the liquid, so that the colony sinks into the 

 depth of the space left in the gelatin by the liquefaction, and 

 the whole surface of the plate seems to be punched out. In 

 gelatin stab-cultures the surface growth shows liquefaction of 

 the gelatin around the colony, and this liquefaction gradually 



