SPIRILLUM CHOLERA ASIATIC JS. 447 



when swimming up stream — i. e., they all point in nearly 

 the same direction, and lie in irregularly parallel, linear 



Fig. 75. 





) W 



Spirllluin of Asiatic cholera. Impression cover-slip from a colony thirty- 

 four hours old. 



groups that are formed by one comma being behind 

 the other without being attached to it. 



Fig. 76. 

 s. 



■=» , ^ ' i -. ;-^ 



Involution-forms of the spirillum of Asiatic cholera, as seen in old cultures. 



On cover-slip preparations made from cultures in the 

 ordinary way there is nothing characteristic about the 

 grouping ; but in impression cover-slips made from 

 young cultures the short commas will nearly always be 

 seen in small groups of three or four, lying together in 

 such a way as to have their long axes nearly parallel to 

 one another. (See Fig. 75.) 



In old cultures in which development has ceased it 

 undergoes degenerative changes, and the characteristic 



