92 



districts, occasional cases of the disease are seen in parts of the territory 

 where the rainfall is not of a tropical character. The method by which 

 animals become infected has not yet been demonstrated ; inoculating 

 the discharge from the lesions or the blood of an infected animal into 

 a healthy one gave negative results ; no bacterial, fungoid, protozoan 

 or metazoan parasites have been demonstrated. The inability to 

 reproduce the disease artificially from horse to horse suggests either 

 that an intermediate host is necessary, or that the appearance of the 

 causative agent in the horse is an accidental phenomenon, its passage 

 through this animal attenuating the virus sufficiently to prevent 

 production of the lesion in healthy tissvies when inoculation of the 

 disease from horse to horse is attempted. Regarding the question of 

 a carrier, it has been shown that the disease is not produced through 

 the agency of leeches. Other possible carriers are Diptera, but 

 evidence is strongly against the likelihood of infection by means of 

 iiies. The number of biting flies, chiefly Tabanidae, is considerable, 

 but with all the species observed there seems to be no preference as to 

 the portion of the horse attacked, the back and the loins being bitten 

 just as often as the legs and abdomen. Also, every horse during the 

 wet season is bitten a great number of times by flies, and there seems 

 to be no relation between the number of fly bites and the occurrence 

 of the disease. The probability is that the virus is not transmitted 

 by an intermediate host. 



Surface (H. A.). Livestock Rarely Poisoned from Spray. — Wkly. ZooL 

 Press Bull., Pennsylvania Dept. Agric, Harrisburg, March 1914, 

 no. 255. 



Ordinary caution in pasturing livestock in orchards after poisonous 

 sprays have been used on the trees will, in the author's opinion, prevent 

 any cases of poisoning. He writes as follows to an inquirer : — 



" I have never known of but one case of poisoning from this, and 

 that was from sheep that were poisoned by pasturing in a small orchard 

 that was sprayed heavily, and they were allowed to remain in the 

 orchard at the time. I think there is absolutely no danger to any 

 livestock from this source if the owner will wait until there is at least 

 one rain after turning the cattle into pasture on it. Where the orchard 

 area is small, so that the stock would be confined to the freshly sprayed 

 parts, and especially where an unusual amount of poison spray has been 

 used, and to such a needless degree as to soak the trees with the spray 

 liquid, there may be some danger of poisoning. I have seen many an 

 orchard sprayed with arsenate of lead and the stock safely pastured 

 there at the same time. The best methods of horticulture do not 

 permit pasturing orchards, especially in the spring of the year when 

 the ground is yet soft. At the time the blossoms fall, which is the 

 time for the first arsenical spray, the gi'ass is short and there is nothing 

 to be gained by pasturing." 



Ross (E. H.). House Flies and Disease. — Jl. R. Soc. Arts, London, 

 Ixii, nos. 3200, 3201, 3202, 20th Mar., 27th Mar., 3rd April 1914, 

 pp. 388-397, 423 and 442. 



The whole question of house flies and their relation to disease is 

 summarised. Dr. P. Caldwell Smith in discussing the paper contended 



