788" MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



toxins, is shown by the fact that immunity against virulent culture may 

 be produced by treatment with presumably sterile filtrates of virulent 

 cultures. 



The bacillus of symptomatic anthrax is rarely found in the general 

 blood before death; but is abundant in the affected muscle and over- 

 lying subcutaneous tissue. It also occurs in great numbers in the bile 

 and intestinal contents. 



Mucous membranes become congested and then very dark. There 

 - is a high fever. Local 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 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. The local subcutaneous tissues are infiltrated, haemorrhagic or 

 gaseous. The local lymph glands are swollen and haemorrhagic or 

 (Edematous. Muscle fibers show various degenerktive changes. 

 The abundant gases are mostly hydrogen and carbon dioxide. 



B. anlhracis symptomatici is about m to 6jii long by o-S/i to o.8m 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 weU-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 excepting mahgnant ceden;ia, 

 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 baciUi are easily 

 demonstrated by the microscope. 



