BACILLUS OF SYMPTOMATIC ANTHRAX. 305 



obtained from a malignant pustule, or the sputum of cases 

 suffering from pulmonary anthrax, will always reveal the 

 characteristic bacilli, perhaps showing spores, and arranged 

 in long chains which may be more or less twisted (see Fig. 

 125). The characteristic growth on the gelatin plates and the 

 gelatin stab will confirm the diagnosis. 



When for sanitary purposes it is necessary to make an 

 examination of a cadaver, a splenic puncture is made, and the 

 fluid obtained by this puncture is examined. 



Bacillus subtilis and the bacillus of malignant oedema may 

 be mistaken for the anthrax bacillus. The former is motile 

 and a strict ae'robe and non-pathogenic, whereas the latter is 

 a strict anaerobe, motile, and is decolorized by Gram's stain. 

 It also differs from the anthrax bacillus in its pathogenesis. 



Bacillus Anthracoides. 



An organism has been described which resembles the an- 

 thrax bacillus so closely as to be mistaken for it at times. 

 This organism is called Bacillus anthracoides. It is short and 

 thick, but not nearly so long as Bacillus anthracis. Neither 

 does it form such long chains. It is encapsulated and forms 

 spores which are stained with difficulty. It is motile, stains 

 easily with the anilin dyes and by Gram's method. 



Bacillus of Symptomatic Anthrax. 



Symptomatic anthrax, also known as "quarter-evil" or 

 "black leg," is a disease of cattle. 



It is due to Bacillus anthracis symptomatici, an organism 

 which also resembles the anthrax bacillus. 



Morphology and biology : The bacillus measures from 3 p 

 to 5 p. in length, and from 0.5 p. to 0.6 p. in width ; it is much 

 smaller than the anthrax germ, has rounded ends, and usually 

 is seen singly or in pairs. It never forms long chains. It 

 is actively motile, and has both lateral and terminal flagella. 

 It forms spores, which are large and centrally located, impart- 

 ing to the organism a clostridium shape (Fig. 136). 



The anilin dyes stain it very readily, but it is decolorized 

 by Gram's stain. It is a strict anaerobe, with a temperature 



20 Bact. 



