310 A MANUAL OF BACTERIOLOGY 



often with the empty spore capsule embracing one end. 

 Sporeless varieties of the anthrax bacillus have been 

 obtained by cultivating under unfavourable conditions, 

 as at a high temperature (44 C.) or in the presence of 

 minute quantities of antiseptics (1 : 1,000 carbolic acid). 



The spores are of considerable practical importance, 

 for they are highly resistant forms, requiring at least some 

 minutes' boiling and three hours in dry air at 140 C. for 

 their destruction, whereas the bacilli without spores are 

 destroyed in ten minutes in the moist condition by a 

 temperature of 54 C. The same resistance occurs towards 

 various germicidal substances. While 1 per cent, carbolic 

 acid solution quickly destroys bacilli without spores, the 

 spores resist 5 per cent, carbolic for days, and at least 

 5 per cent, solutions of high-coefficient phenoloid disin- 

 fectants, acting for not less than twenty -four hours at 

 20 C., are required to kill the spores. The resistance of 

 the spores is stated to increase with their age, but the 

 author has not found this to be the case. Formalin 

 and a formalin-containing disinfectant, " Bacterol," seem 

 to have a selective action on anthrax spores and are 

 efficient disinfecting agents for them. Reichel and Gegen- 

 bauer recommend for the purpose a mixture of 10 per 

 cent, salt and 1 per cent, hydrochloric acid at 30 C., 

 acting for twenty-four hours. Anthrax spores may retain 

 their vitality unimpaired for years in a dried condition. 



Certain anthrax-like bacilli have been described and 

 have to be distinguished from B. anthracis, e.g. B. pseudo- 

 anthracis, B. anthracoides , B. anthracis similis. These 

 are non -pathogenic and are hsemolytic for rabbit, sheep, 

 horse, and ox corpuscles, while the B. anthracis is non- 

 hsemolytic. 1 These forms have no capsule in the animal, 

 nor when cultivated in an inactivated serum, but anthrax 

 has a capsule in such circumstances. 



1 Jarmai, Centr. f. Bakt., Abt. I (Orig.), Ixx, 1913, p. 72. 



