THE BACILLUS OF SYMPTOMATIC ANTHRAX. 529 



Fig. 101. 



fresh cultures, but in the tissues of affected animals as 

 well. 



Though actively motile when in the vegetative stage, it, 

 like all other motile spore-forming bacilli, 

 loses this property and becomes motion- 

 less when spores are forming. 



It is strictly anaerobic and cannot be 

 cultivated in an atmosphere in which 

 free oxygen is present. It grows best 

 under hydrogen, and does not grow under 

 carbonic acid. 



The media most favorable to its growth 

 are those containing glucose (1.5 to 2 per 

 cent.), glycerin (4 to 5 per cent.), or some 

 other reducing-body, such as indigo- 

 sodium sulphate, sodium formate, etc. 



"When cultivated upon gelatin plates 

 in an atmosphere of hydrogen the col- 

 onies appear as irregular, slightly lobu- 

 lated masses. After a short time lique- 

 faction of the gelatin occurs and the 

 colony presents a dark, dense, lobulated 

 and broken centre, surrounded by a 

 much more delicate, fringe-like zone. 



When distributed through a deep 

 layer of liquefied gelatin that is sub- 

 sequently solidified colonies develop at 

 only the lower portions of the tube. 

 The single colonies appear as discrete 

 globules that cause rapid liquefaction pfeiffee.; 

 of the gelatin, and ultimately, coalesce 

 into irregular, lobulated, liquid areas. In some of the 

 larger colonies an ill-defined, concentric arrangement 



34 



Colonies of the 

 bacillus of symp- 

 tomatic anthrax, 

 in deep gelatin 

 culture. (After 

 Pbankel and 



