Zoological Society. 139 



organs, nose, ears, &c. of these animals, and by its poisonous bite de- 

 stroying them in a few hours. A species of the same genus of minute 

 TipulidcB is common in marshy districts in England, and I have often 

 experienced its attacks, which have resulted in the raising of a tu- 

 mour on the part of the flesh which has been attacked, attended by a 

 considerable amount of local inflammation ; and hence we may readily 

 believe the well-authenticated efi^ects produced upon the cattle above 

 described. There are various other insects which attack the horse 

 and ox, such as the Hippoboscce, various species of ticks, Anthomyice, 

 &c, ; and if these do not, from their smaller size, cause a discharge of 

 blood like the large Tabanidce, it is certain that the irritation which 

 they produce not only by their presence upon the skin, but also by 

 the sharpness of their bite, must be very irritating to the quadrupeds 

 which they infest. 



The insects which do not themselves feed upon our cattle, but 

 simply infest them for the purpose of depositing their eggs in some 

 convenient place or other upon their bodies, are in no instance that 

 I recollect provided with an increased development of the mouth 

 organs ; on the contrary, the (Estridce are either entirely destitute of 

 a mouth, or have only very small rudiments of some of the ordinary 

 parts of the mouth, so as to be entirely unfitted for biting or wound- 

 ing cattle. The effects however which some of these species pro- 

 duce are as annoying as those caused by the bites of the Tabani. The 

 female fly of the common horse hot, (Estrus Equi, it is true, instils 

 no dread into the horse round which she is intently engaged in flying, 

 depositing her eggs here and there in particular spots where the horse 

 is certain to lick the hairs, by which means the eggs are introduced 

 into the mouth and pass into the stomach. So little indeed is the 

 horse afl'ected by the presence of this insect, that I have often stood 

 close to one round which the (Estrus Equi has been flying, until the 

 latter has come within reach of my hand, when I have caught it with- 

 out trouble. Another species, (Estrus hcemorrhoidalis^ is however 

 much more troublesome ; depositing her eggs on the lips of the horse, 

 and producing in her endeavours to eff'ect this such an excessive titil- 

 lation, as to cause great uneasiness to the horse, which tosses its head 

 about to drive off its enemy, gallops about, and as a last resource 

 takes refuge in some neighbouring water, where the (Estri never fol- 

 low it. The same kind of effect is also produced in rein deer by the 

 (Estrus Tarandi *, and in oxen by another species of (Estrus, (Est. 

 Bovis, respecting which however much difference of opinion has arisen. 

 At certain seasons, the whole terrified herd, with their tails in the air, 

 or turned upon their backs, or stiffly stretched out in the direction of 

 the spine, gallop about the pastures, finding no rest till they also get 

 into the water. This (Estrus is asserted by some writers to make a 

 strong humming noise, and hence it has been supposed that the herd 

 of cattle are alarmed at the noise ; but this must surely be an ineor- 



* At the present time (April 1851) some of the rein deer in the Gardens of the 

 Society, which were imported last autumn from Lapland, are infected to a re- 

 markable extent with the tumours of this species; there must, I think, be from fifty 

 to a hundred tumours on one of these animals. 



