BAGILL US OF SYMPTOMATIC ANTHRAX. 41 1 



to 38 C., but can also be brought to development at 

 from 16 to 18 C. Under 14 C. no growth is seen. 

 Spore formation appears much sooner at the higher than 

 at the lower temperatures. When its spores are dried 

 upon bits of thread in the desiccator over sulphuric 

 acid and then kept under ordinary conditions they retain 

 their vitality and virulence for many months. Similarly, 

 bits of flesh from the affected areas of animals dead of 

 this disease, when completely dried, are seen to retain 

 the power of reproducing the disease for a long time. 

 The spores are tolerably resistant to the influence of 

 heat : when subjected to a temperature of 80 C. for 

 one hour their virulence is not affected, but an exposure 

 to 100 C. for five minutes completely destroys them. 

 They are also seen to be somewhat resistant to the 

 action of chemicals : when exposed to 5 per cent, car- 

 bolic acid they retain their disease-producing properties 

 for about ten hours, whereas the vegetative forms are 

 destroyed in from three to five minutes ; in corrosive 

 sublimate solution of the strength of 1 : 1000 the spores 

 are killed in two hours. 



When gelatin cultures are examined microscopically 

 the organisms are usually seen as single rods with 

 rounded ends. When cultivated in agar-agar at a 

 higher temperature spores are formed after a short 

 time; the spores are oval, slightly flattened on their 

 sides, thicker than the bacilli, and, as stated, frequently 

 occupy a position inclining to one of the poles of the 

 bacillus, though they are as often seen in the middle. 

 The bacillus containing a spore has usually a clubbed or 

 spindle shape. 



It stains readily with the ordinary aniline dyes. It 

 is decolorized by Gram's method. Its spores may be 



