ANTHRAX. 343 



been somewhat questioned, since it has appeared that if the 

 ordinary bacilli be swallowed by an animal with its food they 

 do not appear to have any power of producing disease. Prob- 

 ably they are so injured by the digestive juices that their patho- 

 genic power is lost. But recent experiment has shown that 

 this does not hold for the spores, since the anthrax spores 

 mixed with the food are capable of inducing the disease. 

 These spores resist the injurious action of the digestive juices 

 and of the other bacteria present in the intestine, and make 

 their way through the intestinal walls into the body and pro- 

 duce the disease. These facts readily explain the common 

 occurrence of intestinal anthrax among cattle, and account for 

 many of the phenomena connected with the outbreaks of epi- 

 demics. 



In other cases the germs may find entrance through abra- 

 sions of the skin. When thus introduced the bacteria first 

 produce a simple abscess in the skin which soon turns into a 

 gelatinous pustule. This pustule does not heal, and from it as 

 a center the bacilli spread rapidly through the body, produc- 

 ing a general disease which proceeds rapidly and terminates 

 fatally. In the case of animals which, like man, are less sus- 

 ceptible to the disease, these abscesses may remain simple 

 localized infections, eventually healing without spreading 

 through the body. The name malignant pustule is appro- 

 priately applied to this form of the disease. In susceptible 

 animals such recovery is very rare. There are other modes 

 of infection, but among animals the disease is most commonly 

 acquired either through the intestine or through skin abra- 

 sions. 



In the body of the infected animals the bacilli grow with 

 the greatest rapidity. An extremely small number of them 

 inoculated into the body of a mouse produces the death of the 

 animal in about twenty -four hours and, after death, the whole 

 body is found to be filled with the bacilli in incalculable 



