332 BACTERIOLOGY. 



Grouping. As found in the slimy flakes in the intes- 

 tinal discharges from cholera patients, Koch likens its 

 mode of grouping to that seen in a school of small fish 

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



FIG. 64. 



Spirillum of Asiatic cholera. Impression cover-slip from a 

 colony thirty-four hours old. 



the same direction and lie in irregularly parallel, linear 

 groups that are formed by one comma being located 

 behind the other without being attached to it. 



FIG. 65. 



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 



