STABLE MANAGEMENT 273 



themselves are about as large as blackberries. A course of 

 sulphate of iron will expedite their departure when they are 

 nearly ready to leave of their own accord ; and a decoction of 

 the ordinary stone-crop used to be looked upon as a remedy 

 in some parts of Ireland. 



The bot-fly is nearly as large as a honey-bee, and hovers 

 close to the place it has selected for laying its eggs, main- 

 taining the while a perpendicular position. It remains 

 perfectly motionless in the air, except for extremely rapid 

 vibration of its wings, which do not emit the slightest 

 hum, or any other sound, and therefore the doomed victim 

 remains quite unconscious of the vicinity of its enemy. 

 When the critical moment arrives the fly darts forward, 

 and suddenly elongating a wondrous ovidepositor, which 

 it curls round in front of it, it just touches the horse and 

 leaves an egg adhering firmly to the hair. It then resumes 

 its former position and continues the process, if undisturbed, 

 until that batch is laid, often depositing thirty or forty eggs 

 at one laying. On subsequent days it will lay as many 

 more. It appears to have a preference for dark-coated 

 horses, if several are feeding together of different colours, 

 and then selects bays and chestnuts, but greys the least 

 of all. 



These drawbacks, however, do not affect the principle of 

 turning horses out to grass, which affords them the great 

 advantage of keeping their muscles employed, and their cir- 

 culation in order, by the daily exercise they take in the 

 course of each twenty-four hours when wandering in 

 quest of food. 



Almost, if not quite, as important as the quality of the 

 herbage is the supply of water, which should always be 

 available, and should be pure and sweet. The germs of 

 parasites may be imbibed with water, as well as taken 

 up with the grass. Shelter from boisterous weather, and 

 shade from the sun when required, are also very desirable, 

 and these may be provided by plantations and belts of trees, 

 which horses seem mostly to prefer to open sheds. Planta- 

 tions help, too, to diversify the ground, which is another 

 advantage, and break the view, thus preventing the bare 



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