BACILLUS ANTHRACIS. 129 



tissues of animals ; from 20 to 25 mikrons when obtained 

 from cultures; and of a uniform thickness of 1.25 mikrons. 

 The ends of the rod seem a little thicker than the rest of the 

 body, and under a low power look square, but with a higher 

 power they are seen to be concave (Fig. 53). 



FIG. 53. 



& 



Bacillus anthracis, highly magnified to show swellings and concavities at extremities 

 of the single cells. (Abbott.) 



It is found singly or in pairs in the blood and tissues of 

 diseased animals, but when cultivated in bouillon or in the 

 hanging drop it forms long threads which may or may not 

 contain spores. 



It is stained by all the alkaline anilin dyes, the spores 



FIG. 54. 



Threads of Bacillus anthracis containing spores. X about 1200. (Abbott.) 



remaining uncolored ; but the latter are easily stained by any 

 of the special methods for staining spores described in the 

 chapter on staining. 



Biologic Characters. The Bacillus anthracis is anaerobic, 

 but can grow without the presence of oxygen. When grown 

 9 M. B. 



