GLANDERS. 2OI 



four days the disease becomes established. The testicles 

 enlarge a little ; the skin over them becomes red and 

 shining. The testicles themselves begin to suppurate, 

 and often discharge through the skin. The animal dies 

 in about two weeks. If such an animal be killed and its 

 testicles examined, the tunica vaginalis testis will be 

 found to contain pus, and sometimes to be partially ob- 

 literated by inflammatory exudation. The bacilli are 

 present in this pus, and can be secured from it in pure 

 cultures. 



The purulent discharges from the noses of horses and 

 from other lesions of large animals generally contain very 

 few bacilli, so that a method of isolation by an animal 

 is very advantageous by greatly increasing the number 

 of bacteria. 



The bacillus is an aerobic organism, and can be grown 

 in bouillon, upon agar-agar, better upon glycerin agar- 

 agar, very well upon blood-serum, and quite character- 

 istically upon potato. It grows in gelatin, but this is 

 not an appropriate medium, because the bacillus develops 

 best at temperatures at which the gelatin is liquid. 



Upon 4 per cent, glycerin agar-agar plates the colonies 

 appear upon the second day as pale-yellow or whitish, 

 shining round dots. Under the microscope they appear 

 as brownish-yellow, thick granular masses with sharp 

 borders. 



The culture upon agar-agar and glycerin agar-agar 

 occurs as a moist, shining layer not possessed of distinct 

 peculiarities. Upon blood-serum the growth is rather 

 characteristic. The colonies along the line of inoculation 

 first develop as circumscribed, clear, transparent drops, 

 which later become confluent and form a transparent 

 layer unaccompanied by liquefaction. 



The most charcteristic growth is upon potato. It first 

 appears in about forty-eight hours as a transparent, 

 honey-like, yellowish layer, developing only at incuba- 

 tion-temperature and soon becoming reddish-brown. As 

 this brown color of the colony develops, the potato for 



