BACILLUS ANTHRACIS. 



549 



preparations they are seen to be composed of a series of 

 rectangular, deeply stained segments. When obtained 

 directly from the blood of an infected animal the free 

 ends of the rods are slightly rounded, but those com- 

 ing in contact with one another are quite square. In 

 cultures the ends are seen to be a trifle thicker than 

 the body of the cell and somewhat concave, giving the 

 appearance of joints of bamboo. At one time much stress 



FIG. 71. 



Anthrax bacillus., X 900 diameters. Agar culture. 



was laid upon these peculiarities as distinguishing marks 

 of the anthrax bacillus; but it has been found that these 

 are the effects of artificial cultivation and not necessarily 

 characteristic of the organism under all conditions. An- 

 other peculiarity of this bacillus is that it is enclosed 

 in a transparent envelope or capsule, which in stained 

 preparations may be distinguished by its taking on a 

 lighter stain than the deeply stained rods which it sur- 

 rounds. 



