148 AIDS TO BACTERIOLOGY 



leaves the bacilli well stained. In sections from the edge 

 of an ulcer, glanders bacilli are few in number and difficult 

 to recognise. 



Pathogenesis. The disease is communicable to man, 

 the horse, mule, ass, sheep, goat, field-mouse, and guinea- 

 pig. Cattle are entirely immune, and white mice and 

 rabbits partially so. Nocard considers the path of en- 

 trance to be often through the alimentary canal. This 

 cannot often be the case with human infections. In man 

 glanders occurs generally through the infective discharge 

 from a diseased horse coming into some traumatic injury, 

 and is a very serious affection. In the horse there are 

 a persistent nasal discharge, ulcers on the septum nasi, 

 and usually an enlarged submaxillary gland. In the 

 horse, when the disease affects the skin on the insides of 

 the legs it is popularly known as ' farcy,' but lesions are 

 invariably found in the lungs (McFadyean). The swellings 

 of superficial lymphatics and glands are known as ' Farcy 

 buds.' Suppuration usually follows. 



The discharge, either from the nostrils or from ulcers 

 or pus, contains comparatively few bacilli, so that it is 

 not easy to demonstrate the bacillus by staining. 



Straus's method of obtaining a pure culture consists in 

 the injection of the suspected discharge into the abdominal 

 cavity of an adult male guinea-pig. If B. mallei is present 

 the scrotum will be red and shining after three days, 

 and the testicles much enlarged and caseous, and the 

 caseous material will contain the bacillus in pure culture. 

 A similar orchitis may, however, be induced by other 

 organisms, or a fallacious result be obtained through the 

 animal not developing orchitis at all, or else dying 

 from general peritonitis before orchitis has time to 

 develop. 



Addison and Hett give the incubation period for man 

 as from a few hours to a year, most generally four to seven 

 days. They also emphasise the necessity for making 

 the injection for Straus's reaction with a culture grown 

 on potato. 



Mallein. The organism is grown in glycerin broth 

 for about six weeks; the culture is sterilised by heat, 

 filtered through porous porcelain; the filtrate when 

 concentrated constitutes mallem. If about 1 e.c. of 

 maUcm be injected into a healthy animal, nothing, or 



