MICROSPIRA COMMA. 



479 



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 

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

 growth progresses liquefaction occurs about this point. 

 In the centre of the depression can be distinguished 



FIG. 77. 



Stab-culture of microspira comma in gelatin, at 18 to 20 C. 



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. 



a small, dense, whitish clump, the colony itself. As 

 growth continues the depression increases in extent 

 and ultimately assumes an appearance that consists in 



