436 



MALIGNANT (EDEMA 



conditions appear first as small whitish points which under the 

 microscope show a radiating appearance at the periphery, 

 resembling the colonies of the bacillus subtilis. Soon, however, 

 liquefaction occurs around the colonies, and spheres with turbid 

 contents result ; gas is developed around the colonies. 



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



FIG. 128. Stab cultures in agar, five days' growth at 37 C. 

 Natural size. 



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

 of quarter-evil (Rauschbrand). 



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

 what broad white line with short lateral projections here and 

 there (Fig. 128, B). Here also gas may be formed, but this is 

 most marked in a shake culture, in which the medium becomes 

 cracked in various directions, and may be pushed upwards so 

 high as to displace the cotton-wool plug. The cultures possess 

 a peculiar heavy, though not putrid, odour. 



