ANTHRAX. 137 



places in which infected animals had been buried. It 

 was, in fact, ascertained that these germs existed 

 above and around the infected carcases, and that they 

 were absent at a certain distance from their burial- 

 place. It is true that putrid fermentation destroys 

 most of the bacteria, but before this occurs a certain 

 number of microbes are dispersed by the gas dis- 

 engaged from the carcase; these dry up and produce 

 germs, which retain their vitality in the soil for a 

 long while. 



The mechanism by means of which these germs 

 are brought to the surface of the soil and on to the 

 grass on which the sheep feed is at once simple and 

 remarkable. Earth-worms prefer soils which are rich 

 in humus or decomposing organic substance, and seek 

 their food round the carcase. They swallow the earth 

 containing the germs of which we have spoken, which 

 they deposit on the surface of the soil, after it has 

 traversed their intestinal canals, in the little heaps 

 with which we are all acquainted. The germs do not 

 lose their virulence in their passage through the 

 worms' intestines, and if the sheep swallow them 

 together with the grass on which they browse, they 

 may contract the disease. The turning-up of the soil 

 by the spade or plough may produce the same effect. 



A certain warmth is necessary for the formation 

 of germs; none are produced when it falls below 12, 

 and the carcases buried in winter are therefore less 

 dangerous than those buried in the spring and sum- 



