ANTHRAX 255 



the protoplasm becomes still more granular, and the 

 shining spots are now well-marked ovoid, highly refractile 

 bodies the mature spores. In old cultures the rods and 

 filaments almost disappear, numbers of spores alone 

 remaining. These spores, when placed under favourable 

 conditions of moisture, warmth, and nutriment, again 

 produce rods and filaments ; a little bud appears at the 

 extremity of the long diameter, which grows in length and 

 ultimately becomes a mature rod, 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 anti- 

 septics (1 : 1000 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 dis- 

 infectants, 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 

 writer has not found this always 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 retain their 

 vitality and pathogenic power unimpaired for years in a 

 dried condition. 



