SYSTEMATIC AND DESCRIPTIVE. 155 



been borne out by experiment.* Bacilli, however, 

 occur in large numbers in the blood and discharges 

 from the nose and mouth of the moribund animals, 

 and in the urine and faeces. They find a nourishing 

 soil in decaying vegetable and animal matter, and 

 having free access of oxygen form copious spores, 

 so that the grass is extensively contaminated. 



In warm and marshy districts the spore formation is 

 still more active, and the spores may be carried 

 by floods over adjacent meadows. As to the mode 

 of infection, the animals may be directly infected 

 through buccal wounds caused by siliceous grasses, 

 or by wounds of insects ; the intestinal and pul- 

 monary mucous membranes are also regarded as 

 pathways of infection. In animals the disease is 

 known as " splenic fever." 



In man the mode of infection is by inhalation of 

 spores, and ingress by the pulmonary or intestinal 

 mucous membrane, or by direct inoculation of a 

 wound or abrasion. The spores are derived from 

 the wool or hides of animals which have died of 

 anthrax, and the resulting disease is known as 

 " wool-sorter's disease," and "pustula maligna." 

 Bacilli are found in the serum of the pustule, and in 

 sputum, urine, faeces, and sweat ; and if the disease 

 prove fatal, in the capillaries throughout the body. 



Attenuation of the virus. By cultivating the 

 bacillus in neutralised bouillon at 42 43 C. for 

 about twenty days, the infecting power is weakened 



* Koch, Mittheil. Gesundheitsamte. 1881. 



