BACILLUS ANTHEACIS SYMPTOMATIC!. 565 



are, as a rule, naturally immune to the disease. The 

 guinea-pig is the most susceptible of test animals. 

 When susceptible animals are inoculated subcutane- 

 ously with pure cultures of this organism, with spores 

 attached to a silk thread, or with bits of tissue from 

 the affected parts of another animal dead of the disease, 

 death ensues in from twenty-four to thirty-six hours. 

 At the autopsy a bloody serum is found in the subcuta- 

 neous tissues extending from the point of inoculation 

 over the entire surface of the abdomen, and the muscles 

 present a dark-red or black appearance, even more in- 

 tense in color than in malignant oedema, and there is a 

 considerable development of gas. The lymphatic glands 

 are markedly hypenemic. 



The disease occurs chiefly in cattle, more rarely in 

 sheep and goats; horses are not attacked spontaneously 

 i. e. y by accidental infection. In man, infection has 

 never been produced, though ample opportunity, by 

 infection through wounds in slaughter-houses and by 

 the ingestion of infected meat, has been given. The 

 usual mode of natural infection by symptomatic an- 

 thrax is through wounds which penetrate not only the 

 skin but the deep intercellular tissues; some cases of 

 infection by ingestion have been observed. The patho- 

 logical findings present the conditions above described 

 as occurring in experimental infection. 



Symptomatic anthrax, like anthrax and malignant 

 oedema, is a disease of the soil, but it shows a more 

 limited endemic distribution than the first, and is differ- 

 ently distributed over the earth's surface than the sec- 

 ond of these diseases, being confined especially to places 

 over which infected herds of cattle have been pastured. 

 It is doubtful whether the bacilli are capable of devel- 



