MODES OF PROPAGATION. 113 



anything unnatural save a cough, a rather dry condition of the 

 skin, and an open or staring coat. There was also to be ob- 

 served on certain occasions a shght watery discharge from the 

 nose, the membrane of which was always of a faint slate- 

 colour, but certainly unabraded, untuberculated, and without 

 erosion. Very similar details are given by Bollinger and by 

 Bagge. The latter, indeed, gives as the result of the examina- 

 tion of one hundred and seven horses of a Dutch regiment, 

 that were killed over a period of three years in consequence of 

 being glandered or of showing symptoms of a suspicious cha- 

 racter, that in the case of ten there were decided structural 

 changes (ulcers in the nasal cavity); in thirteen the alterations 

 were slight ; in fifty-three there were merely nodules in the 

 lungs and a few ulcers in the nasal passages (this number 

 being to all appearance healthy durmg life) ; and in thirty- 

 three no lesions whatever were found. 



c. Modes of Propagation : Contagion, Infection. — Although 

 for a long time it was denied that glanders could be propa- 

 gated in any other manner than by exogenous influences, and 

 that consequently there was no specific poison connected with 

 it, by general consent it is now regarded as a highly contagious 

 malady. 



The certainty of the existence in the various fluids and 

 secretions of the animal of a specific infecting virus has been 

 abundantly demonstrated by experimental investigation. 



There certainly seem degrees of virulence amongst the 

 varied discharges or fluid materials derived from the diseased 

 animals, and with which inoculations have been made, or which 

 have by accident become implanted in the hving animal. And 

 although its action does not entirely depend upon the channel 

 through which an entrance is made into the system, it does 

 seem that such has at least some influence either in modifying 

 its potency or the extent of its absorption into the blood. 



The poison seems to exist in greatest potency in the nasal 

 discharges, the discharge from the chancre-like sore, the 

 various secretions, and the blood. Inoculation can be eftected 

 through the medium of the skin when this is abraded, the 

 mucous membrane by employing friction or without it, and 

 by injection into the connective tissue and the blood. 



Although at the present day it is almost universally ad- 



