OF SELBOHNE. 151 



lit ru ndines alone seem to be annoyed with dipterous insects, 

 which infest every species, and are so large, in proportion to 

 themselves, that they must be extremely irksome and injurious 

 to them. These are the hippoboscce hirundinis, with narrow 

 subulated wings, abounding in every nest ; and are hatched 

 by the warmth of the bird's own body during incubation, and 

 crawl about under its feathers. 



A species of them is familiar to horsemen in the south of 

 England under the name of forest-fly ; and to some of side-fly, 

 from it's running sideways like a crab. It creeps under the 

 tails, and about the groins of horses, which, at their first 

 coming out of the north, are rendered half frantic by the 

 tickling sensation ; while our own breed little regards them *. 



The curious Reaumur discovered the large eggs, or rather 

 pupce, of these flies as big as the flies themselves, which he 

 hatched in his own bosom. Any person that will take the 

 trouble to examine the old nests of either species of swallows 

 may find in them the black shining cases of the pupce of these 

 insects : but for other particulars, too long for this place, we 

 refer the reader to VHistoire d'lnsectes of that admirable en- 

 tomologist. Tom. iv. pi. 11. 



* [The following apparently cruel mode of inuring strange horses to the 

 annoyance of this pest has, I have been assured, been practised in stables 

 iu the New Forest : On the arrival of a horse from another locality, where 

 the forest-fly is unknown, the stranger is placed in a perfectly empty loose 

 box, a quantity of the flies thrown upon him, and he is then shut up for 

 the night. This, it is said, effectually renders him callous to the attacks 

 of the enemy, though doubtless at the cost of a night of torture. Mr. 

 Bennett, in his edition of this work, has the following note (p. 248) : 

 " In the New Forest, in Hampshire, whence the name of forest-fly, the 

 Hippoloxea eqitina, Linn., abounds in such profusion that Mr. Samouelle 

 states, in his ' Entomologist's Useful Compendium/ that he has obtained 

 from the flanks of one horse six handfuls, which consisted of upwards of 

 a hundred specimens." The fact that the fly is found in greater numbers 

 on light-coloured than dark-coloured horses is probably due to their being 

 more easily observed from a distance among the dark heather. T. B.] 



