310 MANUAL OF BACTERlotOGY. 



The injection of typhoid bacilli which have been killed by heat has been 

 resorted to as a preventive measure in a large number of cases in the British 

 army. The results appear to have been partially successful, but the method 

 is still in an experimental stage. 



Bacillus coli communis (often called simply the colon 

 bacillus, Bacterium coli commune of Escherich, and Bacillus 

 pyogenes foetidusof Passet, who obtained it from foul pus; prob- 

 ably the same as Bacillus Neapolitanus of Emmerich). — ^A 

 bacillus with rounded ends, frequently of a short, oval form. 







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y-^ 



~i' -J 



S'ty \ •^-1 • ' '' . 



.' »' ^ ^ i* '~r •> -If ^ 



• \ .^ V - * J ^ 



,>*^ -? V"-«*' * >■ ' 



Fig. 93. — Bacillus coli communis. (X 1000.) 



when it may be difficult to distinguish from micrococci; often 

 longer, even forming threads. It is slightly motile, hav- 

 ing several flagclla. It does not form spores. It stains with 

 the ordinary anihne dyes, but not by Gram's method. It is a 

 facultative anaerobe. It grows well at the room-temperature, 

 but more rapidly in the incubator. It does not Hquefy gelatin. 

 In gelatin plates the surface colonies are of a bluish-white color; 

 the centers are denser than the borders, which are translucent. 

 It usually grows more rapidly in gelatin than the bacillus of 



