THE CHOLERA SPIRILLUM AND ALLIED VARIETIES 



395 



sta^e is reached when the surface looks as if it were covered with little 

 fragments of broken glass. Liquefaction continues about the colonies, 



their structure appears fissured and coarsely granular in texture, and 

 occasionally a hair-like border is formed at the periphery (Fig. 123). 



Fie. 1-" 



FIG. J23 



Cholera colonies in gelatin ; twenty-four to thirty- 

 six hours' growth. X about 20 diameters. 



Cholera colony in gelatin, x 30 diameters. 

 (Dunham.) 



Sometimes the colonies may be retained as compact masses in the zone 

 of liquefaction, and then they are dark yellow or brown in color, and 

 forms occur which are absolutely unlike the typical cholera colonies. 



FIG. 1-J4 



A characteristic series of cholera cultures in gelatin ; one, two, three, four, and six days' growth. 



(Dunham.) 



In (/rlafui-*firl: cultures the growth is at first thread-like and unchar- 

 acteristic. At the end of twenty-four to thirty-six hours a small, funnel- 

 shaped depression appears on* the surface of the gelatin, which soon 

 spreads out in the form of an air bubble above, while below this is a 



