152 ESSENTIALS OF BACTERIOLOGY 



Growth Grow only at high temperature 35 C.; are facul- 

 tative anaerobic. The culture-media must be slightly alkaline; 

 the growth is slow. 



Colonies on Gelatin Plates. Since the temperature must be 

 somewhat elevated, the gelatin media need to be thicker than 

 usual (15 per cent, gelatin), in order to keep it solid, and a 

 temperature of 24 C. used. Little round white colonies, some- 

 what granular in the center, growing very slowly. 



Stab-cultures. Along the needle-track small separate white 

 granules, one above the other, like a string of beads. 



Stroke-culture. On agar, transparent, almost invisible little 

 drops, resembling dew moisture. 



Fig. 88. Bacillus of pneumonia in blood of rabbit (x 1000) (Frankel and 

 Pfeiffer). 



Bouillon. They grow better here than in the other media, 

 remaining alive a longer period of time. 



Blood-serum and Agar. A good growth on blood-serum or 

 blood-agar. 



Staining. Takes Gram's method and the other anilin stains 

 very readily. The capsule stained the same way as that of the 

 Friedldnder bacillus. 



Patho genesis. Rabbits and guinea-pigs, if subcutaneously 

 injected, die in the course of a couple of days with septicemia 

 (o.i c.c. of a fresh bouillon culture suffices). 



