84 ANTHRAX 



sheep, rabbits, and guinea-pigs, infected with anthrax, have been cured 

 by injections of pyocyanase. Among other less thoroughly studied 

 antagonistic bacteria are the staphylococcus, the streptococcus and the 

 pneumonia bacillus. 



Certain fluids of the animal body have a destructive action on the 

 anthrax bacillus. Strange to say, this does not seem to have any 

 marked effect on the susceptibility of the animal to this infection. The 

 blood serum of the rabbit in vitro is markedly bactericidal. Accord- 

 ing to Pane 1 c.c. of such serum will destroy 8,000 anthrax bacilli and 

 still the rabbit is easily susceptible to inoculation with this bacillus. 

 The destructive agent in rabbit's serum seems to be a ferment, inas- 

 much as it is destroyed by a temperature of 56 C. (132.8 F.). The 

 blood of the rat, an animal which has some marked resistance to 

 anthrax inoculation, is highly bactericidal to this organism. This is 

 believed to be due to the relatively high alkalinity of the rat's blood. 

 Fodor showed many years ago that arterial blood is destructive to the 

 anthrax bacillus. 



While mammals are susceptible to anthrax they differ in this par- 

 ticular widely in degree. Epidemics are most common in cattle and 

 sheep and the latter are easily inoculable with pure cultures, while the 

 former are unexpectedly more resistant and require larger doses. 

 Algerian sheep are highly resistant. Hogs are less susceptible than 

 cattle and sheep, and here again there is marked variation in varieties, 

 American and English breeds being more susceptible than those of 

 Hungary. Among our more valuable domestic animals horses are 

 somewhat more resistant than cattle and sheep but in some epidemics 

 they die in great numbers. Dogs are least susceptible but succumb 

 to intravenous inoculations. Goats resemble sheep in susceptibility. 

 Of the smaller laboratory animals, the rat is the least susceptible, 

 while rabbits, guinea-pigs, and mice succumb to every form of inocu- 

 lation. It is said that a single bacillus will kill a guinea-pig. All 

 menagerie animals are susceptible. Birds are highly resistant and 

 epidemics among them are not known, but all may be infected arti- 

 ficially. Frogs are highly refractory but the disease may be induced 

 in them. Snails are said to be wholly refractory. Turtles and fish are 

 susceptible to artificial inoculation, the former readily so. 



