BACILLUS COLI 



RECOGNISED as a normal inhabitant of the human 

 intestine, and as an organism very widely spread in 

 nature, much attention has of late been directed 

 towards this bacillus owing to the difficulty which 

 exists in distinguishing it from the B. Typhosus and 

 also from the supposed pathogenic power which, 

 under certain conditions, it possesses. 



The Bacillus Coli is a short round-ended motile 

 bacillus, aerobic, non-sporebearing, and producing 

 no liquefaction in gelatine (Fig. 58). In morpho- 

 logy it is very variable, sometimes appearing as a 

 short figure of eight bacillus, and sometimes as a 

 distinctly cylindrical organism. In length it varies 

 from '8 fjL to 3 ^u, and is about '5 n in thickness. 

 Two forms are shown in Figs. 58 and 59. Com- 

 pared with B. Typhosus, it is, as a rule, shorter and 

 less bacillary, is less actively motile, and possesses 

 fewer flagella (4-8). Like that organism, it is not 

 .stained by Gram's method. In culture in gelatine, 



