272 MANUAL OF BACTERIOLOGY. 



formed and begun to manifest its action in the patient's 

 body* 



Bacillus anthracis. — ^This is the largest of the patho- 

 genic bacteria with the exception of the spirillum of relaps- 

 ing fever, which is longer but more slender. The bacillus 

 of anthrax is 1.25 ,« broad, and from 3 to 10 /^ long. Bacillus 

 aerogenes capsulatus is of about the same size. The anthrax 

 bacillus often forms long threads. A capsule is sometimes 



I 



^'-•' 





Fig. 76. — Anthrax bacilli, showing Spores. (X 1000.) 



present. It is not motile. It forms spores, which are placed 

 in the centers of the bacilli. The spores form only in the pres- 

 ence of oxygen; they do not appear in the body of an infected 

 animal during Hfe. Anthrax spores are the most resistant 

 of all pathogenic bacteria; they have been known to with- 



* Moschkowitz. Studies, Department Pathology. College Physicians and 

 Surgeons. New York. Vol. VII. I'^Qp-igoo. Annals of Surgery. P. 442. 

 igoo. 



