SPIRILLUM CHOLERA ASIATICS. 571 



in the zone of liquefaction. (See Figs 76 and 77.) 

 Examined under a low-power lens, at the end of sixteen 

 to twenty-four hours, the colonies appear as small, light 

 yellow, round, coarsely granular disks, with a more or 

 less irregular outline. In many cases at this stage an 



FIG. 76. FIG. 77. 



Cholera colonies in gelatin ; 

 Cholera colonies in gelatin; twenty-four thirty-six to forty-eight hours' 

 hours' growth. (DUNHAM.) growth. X about 30 diameters. 



ill-defined halo is seen to surround the granular colony, 

 which by transmitted light has a peculiar reddish tint. 

 The older the colonies become the more the granular 

 structure increases, until a stage is reached when the 

 surface looks as if it were covered with little fragments 

 of broken glass (Koch). Liquefaction continues around 

 the colonies, their structure appears fissured and coarsely 

 granular in texture, and occasionally a hair-like border 

 is formed at the periphery (Fig. 78), or a gray trans- 

 parent zone, until the entire colony breaks up into frag- 

 ments. Sometimes the colonies may be retained as com- 

 pact masses in the zone of liquefaction, and then they are 



