328 Veterinary Medicine. 



the same flora they are attacked. 5th. The disease is unknown 

 on the open prairies of the Western States, where the domestic 

 animals are not allowed to remain over night in the timber belts. 

 6th. With occasional exceptions, it is a disease of late summer 

 and autumn. The dangerous lots can, as a rule, be safely de- 

 pastured in winter and spring. 7th. The pioneers found that 

 they could protect their stock by keeping them coralled on a 

 "tame" piece of land from before nightfall until the fogs and 

 dews became dissipated on the following morning. 



For the land to become ' ' tame ' ' it was only considered neces- 

 sary to cut off the timber and let the sunshine act freely on the 

 surface. Plowing and cultivation did not seem to be requisite in 

 all cases. 



A great drawback to research is the difficulty of securing cases 

 to study. Many lots, formerly dangerous, are no longer so, and 

 others still infecting are kept so secluded that casual cases 

 cannot be fouiid, without much expense for experimental ani- 

 mals. Again, owners do not care to depreciate their land by ac- 

 knowledging that it is infecting. The experiment stations 

 naturally enough look askance, on the proposal to institute ex- 

 pensive experiments on a disease which dies out when the soil is 

 improved. Deadly as the disease is to the individual attacked 

 (man or beast), it is not propagated indefinitely from non-milking 

 subjects, by simple contact or proximity after the manner of 

 plagues. It usually comes to an end by the death or recovery of 

 the subject that has contracted it by consuming meat, milk, but- 

 ter or cheese, the product of an infected animal. The demand 

 for sanitary police measures is, therefore, less urgent. Different 

 observers claim that cases occur in the large cities, through the 

 consumption of meat, butter or cheese, sent from infected locali- 

 ties, but that the city physician fails to make a correct diagnosis. 

 These must, however, be comparatively rare. 



In addition to ingestion as a cause, certain accessory causes 

 ought to be noted. Some men eat the infecting material with 

 impunity, while others succumb to the deadly disease. As the 

 observations have all been made in or near the infecting locali- 

 ties, individuals may be immune through a previous attack and 

 recovery, or there may be a native immunity through unknown 

 conditions. Young children often suffer less than adults, pos- 



