CULTURE OF THE CHOLERA SPIRILLUM. 319 



oval patches of growth that are moist and tolerably 

 transparent. The colonies on this medium at 37° C. 

 naturally grow to a larger size than do those upon 

 gelatin at 22° C. 



In stab cultures in gelatin there appears at the top 

 of the needle track after thirty-six to forty-eight hours 



Fig. 63. 



stab cultures of the spiriUum of Asiatic cholera in gelatin, 

 at 18° to 20° C. 

 a. After twenty-four hours, b. After forty-eight hours, c. After seventy- 

 two hours, d. After ninety-six hours. 



at 22° C. a small, funnel-shaped depression. As the 

 growth progresses, liquefaction will be seen to occur 

 about this point. In the centre of the depression can 

 be distinguished a small, dense, whitish clump, the 



