OF HARTING. 443 



singular mode of reproduction. Collectively they are 

 termed Pupipara, from the fact that their young, of 

 which each female produces one only, are hatched and 

 developed within the ovaries of the parent flies, until 

 they become pupae, in which state, enclosed in their 

 cocoons, they are deposited in the form of com- 

 paratively enormous eggs, and from these the perfect 

 insects escape without any further transformation. 

 Hippobosca equina, the well-known Forest fly, is a 

 winged insect having a short flat body, defended by 

 an integument of such leather-like consistency, that 

 any one attempting to crush it would be astonished 

 at the enormous pressure it is capable of resisting. 

 It is parasitic on the horse, and as it is provided 

 with powerful limbs and stout hooked claws, toothed 

 underneath, it has no difficulty in threading its way 

 quickly and securely among the hairs of the coat, it 

 has also the faculty of moving with equal ease and 

 readiness in any direction, backwards, forwards, or 

 sideways, like a crab, a character which we believe is 

 common to all the species of the group. It does not 

 appear that the punctures made in the skin of the 

 horse by Forest flies are very painful, or that they are 

 followed by such unpleasant consequences as those of 

 the Tabani, indeed, many horses appear to suffer no 

 inconvenience at all from them, we have often seen 

 rough-coated ponies that had led a nomadic kind of 

 life on wastes and commons, utterly indifferent to 

 the swarms of these parasites with which they were 

 infested, on the other hand a single specimen of the 

 forest fly on the sensitive flank of a well-groomed 

 hunter, will sometimes cause the latter to kick and 

 plunge dangerously. This, however, is no doubt due 

 to the excessive titillation caused by the firm foot- 

 hold of the fly as it courses about on the thin coat, 

 and any one who has felt one of these creatures 

 crawling up his arm, and been compelled to throw 

 off his coat in hot haste for the purpose of capturing 

 the assailant, will perhaps appreciate the sensation. 



