92 INSECTS AFFECTING DOMESTIC ANIMALS. 
such terror as to result in costly stampedes, prevention of feeding, and 
nervousness that is very injurious to the animal. 
The flies probably mate in the vicinity of their pupation, and the 
females seek the cattle in open pasture for the purpose of depositing 
their eggs. It is claimed by good observers that they will not fly over 
water or follow cattle when they seek protection in ponds or other 
bodies of water, and also that they do not enter sheds or trouble cattle 
in the shade. The method of deposition has been a subject of much 
discussion. The earlier writers asserted that the insect punctured the 
skin and laid the egg beneath, basing the assertion, it would seem, on 
the great terror and apparent pain of the animal when attacked and the 
position of the grub when first distinguishabie. Réaumur even describes 
the boring apparatus by means of which it is able to pierce the tough 
hide of the ox. Clark and others, however, held with equal strength 
to the view that the eggs are simply deposited on the skin, and the 
larve begin at once upon hatching to burrow beneath. Williston 
(Stand. Nat. Hist., Vol. I!, p. 427) says: ‘“‘The eggs of Hypoderma are 
deposited on the hairs about the front shoulders, neck, and groins of 
artiodactyls only. It was thought for a long while that the female 
thrust the eggs within the skin, but such is now known not to be the 
case.” Miss Ormerod, after careful study of the very young larvee and 
course of their channels, says: ‘‘ From the presence of these small cav- 
ities just below the cuticle, and the fine canal running downward from 
them or from the surface, as the case may be, to the young warble cell 
beneath the hide, I think we shall find that the egg is fixed just beneath 
the cuticle and that the young maggot works its way through the hide 
to where we find it in the early stage. It does not seem possible to me 
that the fly could pass the egg through the hide by means of her egg- 
laying apparatus (or ovipositor), because, as observed, the passage down 
the maggot cell is sometimes of a shape that could not have been caused 
by the ovipositor.” It seems hard to believe that all the fright and 
apparent pain exhibited by the cattle is due simply to the alighting of 
the flies and deposition of the egg on the hair. They can not bite, for, 
as already stated, their mouth parts are rudimentary, and to suppose 
that the cattle are aware of the true nature of the pest and exhibit 
fear simply because of a knowledge that they will cause them future 
trouble is to accredit them with a wisdom rather beyond that usually 
granted to any of the loweranimals. Neither does it seem that all this 
fright could be due simply to their resemblance to bees, for cattle are not 
so frequently stung by them as to develop such an intense fear of them. 
The structure of the ovipositor clearly excludes the possibility of puncture, for, 
though horny, it has a blunt, trifid tip, and is beset at the end with certain minute 
hairs, and structure of this character is a very safe guide to habit. (Riley.) 
Until recently it was assumed as a matter of fact that the larve 
entered through the skin, but the discoveries of Dr. Curtice have 
proven, for lineata at least, that the normal course is by way of the 
