340 Malignant Edema 



conditions. The best preparation, therefore, is made by heating 

 the gelatin to expel any air it may contain, inoculating it while still 

 liquid, and solidifying it in cold (iced) water. In such a tube the 

 bacilU develop in globular circumscribed areas of cloudy hquefaction 

 which contain a small amount of gas. In gelatin to which a little 

 grape-sugar has been added the gas production is marked. 



Agar-agar. — The growth takes place in the form of a cloudy 

 stream, in the lower part of deep punctures in recently heated 

 agar-agar, from which the air has been expelled. If the agar-agar 

 contains i per cent, of glucose, it is soon split up by the gas for- 

 mation. Such cultures give off a very disagreeable odor. 



Fig. 114.— Bacillus of malignant edema, from the body- juice of a guinea-pig 

 inoculated with garden earth. X 1000 (Frankel and Pfeiffer). 



Bouillon.— In deep tubes of recently heated bouillon a diffuse 

 turbidity occurs in about twenty-four hours. After the third day 

 the upper half clears, the baciUi and spores sedimenting or moving 

 away from the oxygen. The culture gives off a very disagreeable 

 odor. 



Milk. — Milk is slowly coagulated, and later digested. 



Potato. — The bacillus grows upon the surface of potato if kept 

 under anaerobic conditions. 



Blood-serum.— Upon coagulated blood-serum, growth occurs 

 under anaerobic conditions, the medium being slowly digested 

 liquefied. 



Vital Resistance. — The baciUi themselves soon succumb when ex- 

 posed to the air. They are destroyed in a few moments by heating 

 to 6o°C. The spores, on the other hand, resist drying and exposure 

 to the atmosphere well and can be kept alive for years in garden 

 earth. The complete destruction of the spores requires exposure to 



