GASEOUS EDEMA BACILLUS 179 



are seen. Spores are generally equatorially situated. Is colored 

 by all the basic dyes, and holds the stain in Gram's method. Stain- 

 ing shows that it possesses a capsule. 



Habitat. The soil, the intestines, and, sometimes, the skin of 

 man. 



Vital Characteristics. Vital resistance is low, the thermal 

 death-point being 58 C. with ten minutes' exposure. It grows 



FIG. 62. B. Aerogenes capsulatus of Welch, in smear. (Williams.) 



best at body temperature. Has lived for one hundred days on 

 culture media in the incubator. It is 'an anaerobe. 



Chemical Activities. Produces gas; does not usually liquefy 

 gelatine, but curdles milk. (Fig. 63.) 



Cultures. Grows best in neutral or alkaline media, producing 

 abundant gas. Colonies appear grayish or brownish- white, and are 

 often surrounded by projections which are feathery or hair-like. On 



