ANTHRAX 105 



Colonies of anthrax bacilli present an extraordi- 

 nary appearance, not unlike wavy locks of hair. The 

 staining and cultivation of the bacillus is not difficult. 



Growth is best at a temperature of 35° C. (95° F.). 

 Without spores the anthrax bacillus displays 

 little resistance to heat, drying, or chemicals, but 

 will survive freezing; but the spores are the most 

 resistant of any pathogenic bacteria, it being said 

 that anthrax spores have retained their vitaUty for 

 thirty years. The bacillus grows without oxygen, 

 but no spore-formation takes place in the absence of 

 oxygen. It is believed that the spores of the anthrax 

 bacillus never form in the body of the animal suffer- 

 ing with anthrax, but develop in the discharges from 

 the body, or in blood drawn from the body, or in the 

 body after death. The last reason is one of especial 

 importance, for with the ordinary burial the spores 

 might retain their vitality in the soil for years. It is 

 customary to cover the carcasses of animals dead from 

 anthrax with large quantities of lime, which effectu- 

 ally prevents spore-formation. Pastures which have 

 been used by infected cattle are declared to be un- 

 safe after ten or fifteen years. 



The usual method of infection for cattle is by 

 grazing in infected pastures. Epidemics of anthrax 

 have occurred as the result of pastures being over- 



