MICROSCOPICAL CHARACTER OF CULTURES 435 



human subject. Malignant oedema can be readily produced by 

 inoculating susceptible animals, such as guinea-pigs, with garden 

 soil. The bacillus is also often present in the intestine of man 

 and animals, and has been described as occurring in some 

 gangrenous conditions originating in connection with the 

 intestine in the human subject. 



Microscopical Characters. The bacillus of malignant oedema 

 is a comparatively large organism, being slightly less than 1 /A 

 in thickness, that is, thinner than the anthrax bacillus. It 

 occurs in the form of single rods 3 to 10 /A in length, but both 

 in the tissues and in 

 cultures in fluids it fre- 

 quently grows out into 

 long filaments, which may 

 be uniform throughout or 

 segmented at irregular 

 intervals. In cultures on 

 solid media it chiefly 

 occurs in the form of 

 shorter rods with some- 

 what rounded ends. The 

 rods are motile, possessing 

 several laterally placed 

 flagella, but in a given 

 si>ecimen, as a rule, only 

 a few bacilli show active 

 movement. Under suit- 

 able conditions they form 

 spores, which are usually 

 near the centre of the rods 

 and have an oval shape, 



their thickness somewhat exceeding that of the bacillus (Figs. 

 126, 127). The bacillus can be readily stained by any of the 

 basic aniline stains, but loses the colour in Gram's method, in 

 this way differing from the anthrax bacillus. 



Characters of Cultures. This organism grows readily at 

 ordinary temperature, but only under anaeroltic conditions. In 

 a puncture culture in a deep tube of glucose gelatin, the growth 

 appears as a whitish line giving off minute short processes, the 

 growth, of course, not reaching the surface of the medium. 

 Soon lii|iiet'a-tion occurs and a long fluid funnel is formed, with 

 turbid contents and flocculent masses of growth at the bottom. 

 At the same time bubbles of gas are given off, which may split 

 up tin- gelatin. The colonies in gelatin plates under anaerobic 



FIG. 127. Bacillus of malignant oedema, 

 showing spores. From a culture in 

 glucose agar, incubated for tliree days 

 at 37 C. 



Stained with weak rarbol-fuchsin. x 1000. 



