494 INFECTION AND IMMUNITY. 



Resistance The bacillus itself shows no unusual resistance, 

 lence! but its spores are more resistant than those of any 

 other pathogenic bacterium. When dried on a 

 thread they have been known to live for from ten 

 to twelve years. Corrosive sublimate (1-2000) 

 kills them in forty minutes (Fraenkel), and direct 

 sunlight in about 100 hours (Moment). Bacillus 

 pyocyaneus, streptococci, staphylococci and the ba- 

 cillus of Friedlander are said to antagonize its 

 growth, and Eettger found that the dried B. prodi- 

 giosus decreased the virulence of the organism for 

 animals when the two were injected. 



The anthrax bacillus is remarkable for its infec- 

 tiousness. A twenty-millionth of a loop of a viru- 

 lent culture will cause a fatal infection in mice, 

 guinea-pigs and rabbits, when given subcutaneous- 

 ly. A systemic infection may be produced by feed- 

 ing the spores or causing animals to inhale them. 

 The gastric juice is able to kill the bacilli, but not 

 the spores, which germinate after they reach the 

 intestines. 



The organism is distributed by the excretions 

 of diseased animals, and after their death the ad- 

 jacent soil becomes heavily infected by the dis- 

 charges which escape from the intestines and blad- 

 der. In this situation the bacilli pass into the 

 sporing stage, in which they remain viable and 

 virulent for a long time. 



infection The infection of herds usually is accomplished 

 Atria, ^ fa Q i n g es ti n of spores which have been distrib- 

 uted in this way, the spores germinating, as de- 

 scribed above, after they have reached the intes- 

 tines. The disease may be primary in the skin in 

 the form of malignant pustule. In man malignant 

 pustule is the commonest type of infection, occur- 



