Cultivation 



451 



of making a bacteriologic diagnosis of the disease in a 

 suspected case, is probably that of Schottelius. 



A small quantity of the fecal matter is mixed with bouillon and 

 stood in an incubating oven for twenty-four hours. If the cholera 

 spirilla are present they will grow most rapidly at the surface of the 

 liquid when the supply of air is good. A pellicle will be formed, a 

 drop from which, diluted in melted gelatin and poured upon plates, 

 will show typical colonies. 



Cultivation. The cholera organism is easily cultivated, 

 and grows luxuriantly upon the usual laboratory media. 



Fig. 132. Spirillum of Asiatic cholera; colonies two days old upon 

 a gelatin plate. X 35 (Heim). 



Colonies. The colonies grown upon gelatin plates are 

 characteristic and appear in the lower strata of the gelatin 

 as small white dots, which gradually grow out to the surface, 

 effect a slow liquefaction of the medium, and then appear 

 to be situated in little pits with sloping sides (Fig. 132). 

 This appearance suggests that the plate is full of little holes 

 or air-bubbles, and is due to the slow evaporation of the 

 liquefied gelatin. 



Under the microscope the colony of the cholera spirillum 

 is fairly well characterized. The little colonies that have 



