ANTHRAX OR SPLENIC FEVER 305 
all the time retain their power of developing when placed under 
proper conditions. All of these facts evidently make the dis- 
infecting of an infested locality a matter of very great difficulty. 
Method of Infection.—Although this disease is extremely fatal, 
animals affected rarely recovering, it is not particularly contagious, 
and is rarely communicated directly from animal to animal. 
One common method by which cattle are infected appears to be 
through the food which they crop in the fields. It has often been 
noticed that the disease breaks out in a herd shortly after it has 
been turned out into a new pasture. In some of these cases which 
have been investigated the explanation is simple. In such 
pastures bodies of animals dead from anthrax have been buried, 
and the spores have remained alive for many years. Now, 
although these spores may have been buried some distance below 
the surface, they are eventually brought to the surface. One 
of the means by which they are brought up from under ground 
is through the agency of earthworms, and the spores are later 
taken into the stomachs of cattle feeding on the grass. These 
spores resist the 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, producing the disease. These 
facts readily explain many of the phenomena connected with the 
outbreaks of epidemics. 
In other cases the germs may find entrance through abrasions 
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, producing a general 
disease which may terminate fatally. The name malignant 
pustule is appropriately applied to this form of disease. In 
susceptible animals such recovery is very rare. In the case of 
animals which, like man, are less susceptible to the disease, these 
abscesses may remain simple localized infections, eventually 
healing without spreading through the body. There are other 
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