Microhic Diseases Individually Considered. 261 



the hand at the place of inoculation, and by an ap- 

 preciable swelling of the subglossal lymphatic glands. 

 In a healthy animal the same injection would produce 

 no effect. Mallein should, therefore, facilitate the 

 diagnosis of the disease in doubtful cases. 



Etiology and 'pathogeny. — The efficient cause of 

 glanders is the bacillus maUei. This microbe, under 

 natural conditions, multiplies only in the organism 

 of solipeds and its origin must be looked for in 

 these animals. The virulent substances cast off by a 

 glanderous subject are : nasal discharge, pus of ulcers, 

 saliva, urine, pus of setons, and semen ; the virulence 

 of the last four products, though less constant than 

 that of the first, is nevertheless incontestable and has 

 been demonstrated by experiment. To this list must 

 be added, in the case of the cadaver, the various 

 specific lesions and the muscles. Inoculation of 

 guinea pigs with muscle juice has produced the dis- 

 ease in a certain number of cases. 



Contagion takes place by direct or indirect con- 

 tact. There is direct contact from the horse to man 

 when the latter inoculates himself in manipulating 

 or in dressing glanderous lesions; from horse to 

 horse when two horses, one of which is glandered, 

 occupy adjacent stalls in a stable, or work side by 

 side so that they can easily touch each other. The 

 disease is occasionally transmitted through sexual in- 

 tercourse ; Zundel mentions the case of a glandered 

 stallion which infected more than fifty mares. The 

 eventual passage of the glanders bacillus into the 

 semen accounts for this mode of infection, whilst 

 their filtration through the placenta occasions trans- 

 mission of the disease from mother to foetus, an 



