150 MICRO-ORGANISMS AND DISEASE. [CHAP. 



elements appear constricted in the middle, preparatory to 

 division. Between each two elements is a fine septum. 



Bacilli anthracis when growing at ordinary temperatures 

 on a solid medium (e.g. a mixture of gelatine and broth, or 

 Agar-Agar and peptone) show a very peculiar modification, 

 inasmuch as some of the elements assume a spherical or oval 



FIG. 82. FROM AN ARTIFICIAL CULTURE OF BACILLUS ANTHRACIS, CARRIED ON 

 AT ORDINARY THMPERATURE AND ON SOLID (GELATINE) MATERIAL. TORULA 

 FORM. 



Magnifying power 450. (Stained with Spiller's purple.) 



shape, a torula-form, and as such they multiply by gemmation 

 and division, and form clusters or arrange themselves in 

 chains. By and by each of these spherical elements 

 elongates into a rod, and when all elements have undergone 

 this change we have the typical smooth filament of the 



