SYSTEMATIC AND DESCRIPTIVE. 28 1 



balsam. The giant cells are then stained pink, while 

 their nuclei are brown and the bacilli blue (Plate XVIII., 

 Fig. i). 



Bacillus anthracis (Bacteridie du charbon, Bacil- 

 lus of splenic fever, woohorters* disease, or malignant 

 pustule). Rods, 5 20 JLC long and i 1*25 //, broad, 

 and threads ; spore-formation present. As a 

 thorough knowledge of the life-history of this 

 bacillus is of the greatest importance, inasmuch as 

 it is without any doubt the actual cause of wide- 

 spread disease, the various steps to be followed 

 in a practical study of it will be successively treated 

 in detail. Its morphological and biological charac- 

 teristics have been very completely worked out, 

 and it serves as an excellent subject for gaining 

 an acquaintance with the various methods that 

 should be employed in studying micro-organisms. 

 It is found that a mouse inoculated with the bacillus 

 or its spores will die in from twenty-four to forty- 

 eight hours, or more rarely in from forty-eight to 

 about sixty hours. 



Examination after death. The details to be ob- 

 served in the autopsy have already been described 

 (p. in). The spleen is found to be consider- 

 ably enlarged, and may be removed (p. 112), and 

 examined by making cover-glass preparations, 

 inoculations, and subsequently sections. 



P Cover-glass preparations. In cover-glass prepara- 

 tions of the blood of the spleen the bacilli are found 

 in enormous numbers. Preparations should be 



