636 MICROBIOLOGY OF THE DISEASES OF MAN AND ANIMALS. 



swellings occur which are at first sensitive and later insensitive and gaseous. 

 There is usually developed a very marked swelling of a front or hind 

 quarter or of the neck, with rapid formation of gas. The serous membranes, 

 particularly the pleura and peritoneum, develop very severe inflammation 

 with haemorrhages and infiltrations and corresponding exudation in the 

 cavities. General decomposition is rapid and the swelling may show a 

 slight acetone odor. Muscle fibers show various degenerative changes. 

 The abundant gases are mostly hydrogen and carbon dioxide. 



B. anthracis symptomatic* is about 3^ to 6^ long by 0.5^ to 0.8^ thick. This is 

 a spore-bearing bacillus of drum-stick shape or spindle shape and is anaerobic. It 

 grows best at about 37. It stains either by the simple aniline dyes or by Gram's 

 method. In artificial cultures, it sometimes shows long forms. This organism is 

 motile for a short time, but soon loses this power, probably on account of the oxygen 

 to which it is exposed. It shows well-defined flagella and develops spores. The specific 

 organism may be demonstrated by the microscope in the blood without staining if 

 done soon after death. 



The bacillus of symptomatic anthrax is easily demonstrated in cover- 

 glass smears from the affected tissues, and is very different from the bacteria 

 of anthrax and haemorrhagic septicaemia, the only diseases liable to be 

 mistaken for blackleg. Anthrax gives a surface growth and is aerobic. 

 Symptomatic anthrax gives no surface growth and is anaerobic. This 

 organism may also be demonstrated by animal inoculation. The 

 guinea pig serves well for this purpose; it is very susceptible to inoculation 

 and gives a characteristic blackleg reaction in both symptoms and lesions. 

 From the lesions thus produced the characteristic bacilli are easily 

 demonstrated by the microscope. 



Elimination of this virus from the body occurs chiefly in the various 

 discharges, and especially in the manure and also in general decomposi- 

 tion of the carcass. Dissemination of this disease is chiefly if not ex- 

 clusively by diseased carcasses and parts of carcasses and by the dis- 

 charges. 



Carcasses should be burned if possible; otherwise very deeply buried 

 and covered with lime. Contaminated grounds, or stable floors must 

 be thoroughly disinfected, for the infection is very persistent and difficult 

 to eradicate except by most vigorous effort since the spores are very 

 resistant to heat and drying. Preventive inoculation after the method of 

 Arloing and Kitt is very satisfactory. Their vaccine consists of specially 

 treated muscular tissues from the diseased part. 



