REPORT ON DOORINE. 47 



' materies morbi ' of the disease, and for such flies to convey the 

 disease to susceptible animals in close proximity by direct in- 

 fection is bufc an easy matter, as proved by me in the case of Surra 

 as early as 1891. During protracted periods, the mucus collected 

 from the vagina has been demonstrated at intervals to contain 

 immense numbers of mature and developmental forms of the try* 

 panosoma ; further, muous dropping to the ground from the lower 

 commissure of the vulva has been found, on miscroscopical examina- 

 tion, to contain as many as 5 to 8,000 trypanosomata in one thin 

 cover-glass preparation. Flies are continually settling on the vulva of 

 the affected mares, and collect also on the mucus which escapes from 

 the passage and falls to the ground. Consequently, without the 

 affected animals are protected from flies and the stable floors kept 

 clean and disinfected, it is possible for flies to carry the 'contagium* 

 and communicate the disease by direct infection to healthy equineg, 

 at all events those situated in their immediate vicinity. 



Section VIII SUSCEPTIBILITY OF DIFFERENT ANIMALS. 



Horses are the most susceptible animals to Dourine. The 

 power of resistance to the disease is more marked in stallions than 

 in mares. The malady runs its course in a shorter period in im- 

 ported animals than in the indigenous, and certain country-tatoog 

 appear to be insusceptible to the subcutaneous inoculation of con- 

 siderable amounts of infective blood. 



Susceptibility in the donkey of this country (C. B.) varies, but 

 in no instance is it in any way comparable to that of the horse, 

 although occasionally the eruption of plaques may be a marked 

 symptom. 



The pariah dog is in the great majority of instances insuscep- 

 tible, even inoculation into the anterior chamber of the eye pro- 

 ducing no effect, young puppies exhibiting tue same degree of 

 resistance to the disease that adult dogs show. 



The rabbit also ehows a certain degree of resistance to the inocu- 

 lated disease, as is also the case in the rat. (Mia Deccumanus.) 



