204 APPLIED BACTERIOLOGY 



extent dependent on the size of the dose, and the larger 

 animals often recover. When this is so, they are said to 

 possess a subsequent immunity, which may also, according 

 to Eoux and Chamberlain, be induced by the injection of 

 filtered cultures, or of serum from animals that have died 

 of the disease. 



SYMPTOMATIC ANTHRAX. 



The specific organism was discovered by Bollinger and Feser — 

 Morphology — Method of staining — Growth on media — Pathogenesis 

 — Production of artificial immunity. 



The bacillus of symptomatic anthrax was first described 

 by Bollinger and Feser in the year 1878, who obtained it 

 from the affected tissues in animals suffering from ' quarter- 

 evil.' 



The bacillus is a rod about 4 /u. long and 0'5 fj, thick. It 

 is motile, and forms spores, which are situated at different 

 positions in the rod, and, from their large size, cause its 

 distortion. The thermal death-point of the bacillus is 

 80° C, while that of the spores may be very considerably 

 higher, especially when dried. 



Method of Staining. — The bacillus may be stained by the 

 ordinary aniline dyes, and the fiagella may be demonstrated 

 by staining them first with Ziehl's stain, and then staining 

 the bacilli with methylene blue ; the fiagella may be stained 

 by Loffler's method. 



Growth on Media.- — The organism is strictly anaerobic, 

 and grows best on media containing a small addition of 

 glucose ; it can either be grown in stab culture or in an 

 atmosphere of hydrogen. Spores are most quickly formed 

 in agar cultures incubated at blood-heat. In both agar and 

 gelatine gas is formed, and the cultures have a peculiar 

 odour, while gelatine is slowly liquefied. 



