156 MICRO-ORGANISMS AND DISEASE. [CHAP. 



mass of the bacilli, are quite innocuous when inoculated into 

 animals, or into fresh nourishing media. But as long as 

 there are any good protoplasmic elements of the bacilli left, 

 the culture is virulent to rodents, with the exception of mice, 

 as will be stated presently ; and it is capable, when trans- 

 ferred to new suitable nourishing media, of starting new 

 cultures that prove virulent to all rodents and sheep. 



The same holds good of the bacilli in the blood and organs 

 of an animal dead of anthrax, provided the animal be not 

 opened, and its organs, exudations, or urine be not exposed 

 to the free air ; for the bacilli not exposed to the air gradually 

 degenerate, and the blood and organs of such an animal 

 although at first deadly poison to other susceptible animals, 

 become at length quite innocuous. Systematic observation 

 has shown me that small animals, such as mice and guinea- 

 pigs, when kept unopened or buried in earth, become quite 

 innocuous after five to eight days, the anthrax-bacilli having 

 by this time, by degeneration, altogether disappeared from the 

 blood, spleen, and other organs. Pasteur's statement that 

 in animals dead of anthrax and buried, the bacilli form 

 spores, that these spores are taken up by earthworms and 

 carried to the surface of the soil, where they are deposited 

 with their castings and thus are capable of infecting animals 

 grazing or sojourning on this soil, is not borne out by the 

 above observations. And further, Koch has proved l by 

 direct experiment that spores of anthrax-bacilli when mixed 

 with earth in which worms are present, are not taken up by 

 these creatures. 



Drying bacilli of the blood or of a culture in a thin layer 

 invariably kills them, but the spores remain unaffected. 



The bacilli of the blood of a rodent dead of anthrax are 



. J Miltheil. a. d. k. Gcsundhdtsamte, 1881. 



