336 



BACTERIOLOGY. 



cultures from other sources they may be somewhat 

 retarded. 



On plates of nutrient agar-agar the appearance of the 

 colonies is not characteristic. They appear as round or 

 oval patches of growth that are moist and tolerably 



PIG. 67. 



a bed 



Stab cultures of the spirillum of Asiatic cholera in gelatin, 



at 18 to 20 C. 



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

 two hours, d. After ninety-six hours. 



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 



