ANTHRAX 91 
of affected animals. Its spores are very resistant to the normal 
destructive agencies in nature. Consequently when anthrax is once 
introduced into a locality it tends to remain there for many years, 
possibly causing from time to time a few cases or more serious 
epizodtics, or epidemics. The spores are frequently carried in the 
wool, hair, hides, hoofs and horns taken from animals sick or dead of 
anthrax. Through these agencies anthrax has been introduced into 
distant localities. 
Bacterium anthracis is a rod-shaped organism varying in length from 
1 to + uw, but having a quite uniform breadth of about one micron. 
In a suitable medium it grows out in long flexible fllaments which com- 
bine to form thread-like bundles. When examined, the ends of the 
rod seem to be square cut. In preparations from animal tissues there 
appear sometimes to be slight concavities in the ends of the segments 
when two of them are united. In the preparations, capsules are 
easily recognized. It is believed by Kodama and others that the 
capsule is a protection to the bacterium against phagocytes but that 
it does not protect against the bacteriological action of the blood 
serum. In cultures spores are formed. These are oval, highly 
refractive bodies held within the cellular envelopes of the filaments, 
but later they are set free by the dissolution of this membrane. They 
stain readily with the aniline dyes and also by Gram’s method. 
The bacterium of anthrax itself is not an especially hardy organism. 
On the contrary it is easily destroyed by weak disinfectants and it has 
a low thermal death point. Its spores, however, are among the most 
hardy of bacterial life to resist chemical and thermal agents. They 
resist drying for months or years and often boiling for a half-hour or 
longer does not destroy them. On that account it is very difficult to 
eliminate the virus from infected pasture lands, especially if they are 
wet or marshy. Hutyra and Marek state that the spores may pass 
through the digestive tract without germinating. 
As the spores may remain on the soil in a dormant condition for 
many years, it sometimes happens that the disease does not appear 
until long after the introduction of the virus. Anthrax has been 
known to break out among cattle grazing on a field in which the 
carcasses or hides from affected animals were buried many years 
before. Through some means the spores seem to be able to get to the 
surface and contaminate the grass. The virus may be introduced 
with blood or bone fertilizers, hides, hair or wool from infected coun- 
tries. When the extent of this traffic is realized, it is easy to under- 
