364 MANUAL OF BACTERIOLOGY. 



outside of the cells, but mostly within the cells. Most persons 

 who are affected with leprosy have the bacilli in the nasal secre- 

 tion.* The disease must be communicated directly from one 

 individual to another, for no explanation can be given for 

 the appearance of the infection in any patient, except by com- 

 munication with some other case. Still transmission by 

 contact seems not to take place easily. 



Bacillus Mallei (bacillus of glanders). — A slim bacillus with 

 round or pointed ends, which often shows alternate light and 

 dark spots in stained preparations. Branching forms have 

 been described. It is not motile. It probably does not form 

 spores. It does not retain the stain by Gram's method. 

 After staining with the ordinary aniline dyes it is easily decolor- 

 ized, and on that account it is difficult to demonstrate in sections 

 of tissues. It is facultative anaerobic. It grows at the room 

 temperature, but better in the incubator. It grows slowly on 

 gelatin, and does not liquefy it, or only after a long time. On 

 agar it produces a moist, white growth; on blood-serum, a 

 yellowish or brownish growth; blood-serum is not liquefied. 

 Milk is coagulated slowly, and the reaction becomes acid. 

 On potato, the growth one or two days in the incubator is 

 translucent amber-yellow, later a reddish brown, while the 

 surface of the potato becomes discolored. 



In the first few days on potato, cultures resemble those of B. 

 pyocyaneus on this medium.f 



In the horse and ass it produces the disease known as 

 glanders, which affects the mucous membrane of the nasal 

 cavity. When the skin is involved, the disease goes by the 

 name of farcy. In the nose, nodules appear in the mucous 

 membrane which become necrotic, forming ulcers. They 

 may become confluent, and may extend along the adjacent 

 surfaces as far as the lungs. There is a profuse discharge 



*Gunther. Loc. mt. p. 509. 



fFrothingham. Journal of Medical Research. Vol. VI., p. 334. 



