18 
serviceable observations by writers well acquainted with 
the subject, published in the ‘ Leather Trades’ Circular ’ 
in 1877-78. 
Firstly, about 'preventing egg-laying. As a rule the 
(Estridce , that is to say the Bot Flies, are chiefly on the 
wing at noontide on sunny days ; it would therefore 
appear highly desirable that as far as possible cattle 
should have the means of sheltering amongst trees or 
bushes, where there would be some degree of shade, 
coolness, and moisture, which the Warble Fly dislikes. 
In the case of valuable milch cattle and young animals 
it would be well worth while to provide them with the 
access to sheds (now sometimes given as a preventive for 
attack) on a larger scale, and in a great many more in¬ 
stances than is at present done. It will often be found 
that one herd is badly attacked, and another near not at 
all, without the owner knowing why ; but there is clear 
proof that an animal that is tethered so that it cannot 
get from the Flies is more liable to attack. 
The shelter is not only needed for protection from 
egg-laying, but also to save the cattle from the intense 
terror which, when Fly-attack is about, sends them at a 
persistent trot or headlong gallop, and to their own 
great injury, in every direction. I think that in this 
matter, bad as the Bot Fly is, it bears a double share of 
blame, for here—that is in this one point of irritating the 
cattle to a gallop—the blood-sucking Gad Fly bears a 
part also. I have good observation of it being then de¬ 
tached from the brisket of the animal. But all writers 
agree that the Bot Fly does not go over water; therefore, 
in this point of view, the trampled shallow watery spots, 
which one can scarcely call pools, in which the headlong 
pace may be seen brought to an end, are of much service. 
With regard to prevention of egg-laying or destruction 
of the hatching maggot by treatment of the coat of the 
animal , there are many appliances calculated to protect 
the coat, and also to render it as unserviceable for egg- 
laying on as w T e might say a gravel path would be to a 
Flesh Fly. Soft-soap and black sulphur mixed in grease, 
