Cultivation 



343 



a bacterium, and a bacillus. It is commonly surrounded 

 by a distinct transparent capsule, hence its name "capsule 

 bacillus" and Bacillus capsulatus mucosus. The organism 

 is non-motile, has no spores and no flagella. It stains 

 well with the ordinary anilin dyes, but does not retain the 

 color when stained by Gram's method. 



Cultivation. Colonies. If pneumonic exudate be 

 mixed with gelatin and poured upon plates, small white 

 spheric colonies appear at the end of twenty-four hours, and 

 spread out upon the surface of the gelatin to form whitish 

 masses of a considerable size. Under the microscope these 

 colonies appear irregular in outline and somewhat granular. 



Fig. 102. Bacterium pneumonicum (modified after Migula). 



Bouillon. There is nothing characteristic about the 

 bouillon cultures of Friedlander's bacillus. The medium is 

 diffusely clouded. 



Gelatin Puncture. When a colony is transferred to a 

 gelatin puncture culture, a luxuriant growth occurs. Upon 

 the surface a somewhat elevated, rounded white mass is 

 formed, and in the track of the wire innumerable little 

 colonies spring up and become confluent, so that a "nail- 

 growth" results. No liquefaction of the gelatin occurs. 

 Gas bubbles not infrequently appear in the wire track. 

 The cultures sometimes become brown in color when old. 



