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- 
