OTHER DISEASES CAUSED BY BACTERIA 309 



Louisiana lowlands. Anthrax has been epizootic in Missouri at 

 intervals since 1836. 



It is more common in the early spring and summer, although 

 cases are not infrequently observed in winter. 



The cause of anthrax is the anthrax bacillus (Bacterium anthracis), 

 a spore-forming, somewhat large, rod-shaped organism with square 

 ends. The germ is not easily destroyed outside of the animal 

 body, and pastures, stables, or material such as hides, etc., in- 

 fected with the bacillus, may harbor it for long periods. Infection 



Anthrax bacilli in chains with spores. 



may follow, when taken into the body in the food, through in- 

 haling air laden with infected dry dust, or through the broken or 

 even healthy skin. 



Once gaining access to the body, it meets conditions favoring 

 its development and multiplication. It also grows outside of the 

 animal body, and pastures once infected may carry the germ for 

 many years. If it is placed under unfavorable conditions it forms 

 spores, and these are so resistant to destructive agents that they 

 may lie quiescent for long periods of time, only again to form 

 virulent germs if they gain access to the body. Thus a grave where 

 an animal killed by anthrax has been buried may keep a pasture 



