CHARACTERS OF CULTURES 



451 



it grows readily at the room temperature, but the optimum is 

 the temperature of the body. 



In deep tubes of glucose agar at 37° C. growth is extremely 

 rapid. Along the line of puncture, growth appears as a some- 

 what broad whitish line, with short lateral projections here and 

 there (Fig. 131, B). Gas may be formed, but this is most 



Fig. 131. — Stab cultures in agar, five days' growth at 37° C. 

 Natural size. 



A. Tetanus bacillus. B. Bacillus of malignant fledeina. C. Bacillus 

 of quarter-evil (Rauscbbrand). 



marked in a shake culture. The individual deep • colonies are 

 woolly in appearance without definite centre, whilst the super- 

 ficial ones are thin discs with irregular peripheral radiations. 

 The growths generally are like those of the b. tetani, but have 

 a somewhat coarser character. Cultures in gelatin present 

 somewhat similar features, and the deep colonies have been 

 compared to those of the b. subtilis ; liquefaction of the medium 



