360 BACTERIOLOGY. 



middle than at the poles ; it forms, like the " comma 

 bacillus," screw-like, twisted threads (Fig. 68). 



It is supplied with a single flagellum at one of its 

 ends, and is, therefore, motile. 



It, like the comma bacillus, readily undergoes 

 degenerative changes under conditions unfavorable to 

 growth and presents the variety of shapes grouped under 

 the head "involution forms." According to Buchner 

 this is especially the case when the medium in which 

 they are growing contains glucose (5 per cent.) or gly- 

 cerin (2 per cent.). 



FIG. 68. 



Vibrio proteus, Finkler-Prior bacillus, from culture on agar-agar twenty- 

 four hours old. 



CULTURAL PECULIARITIES. On gelatin plates the 

 development of its colonies is far more rapid, and 

 liquefaction far more extensive, than in the case of the 

 cholera spirillum. After twenty-two to twenty-four 

 hours in this medium at 20 to 22 C. the average size 

 of the colonies is about double that of the comma bacillus. 

 The colonies are darker and denser and do not present 

 under the low lens the same degree of granulation and 

 subsequent lobulation, and they do not become serrated 

 or scalloped around the margin as is the case with Koch's 

 organism. After twenty-two to twenty-four hours they 

 are usually nearly round, regularly granular, and more 



