582 



ARTICULATA. 



THE OX-FLY. 



skin uf young cattle, producing a swelling which suppurates and forms a purulent humor, on 



which the larvae feed. The Sheep-Fly, 

 (Estrus ovisy is less than half an inch long ; 

 it deposits its egg in the nostrils of the sheep; 

 the larva) ascend to the cavity of the fore- 

 head, where they remain for the season, 

 often producing vertigo in their victims. 



The Breeze-Fly, or Bot-Fly, CEsfrus 

 equi, is distinguished from the other species 

 il~^/ by the smoothness of the thorax, and by 

 the eyes in both sexes being equidistant 

 from each other ; it is not quite half an inch 

 in length, with gauze-lite yellow and brown 

 wings; its chest is of a rusty color, approach- 

 ing to a brown hue on the sides, and with 

 a yellow tinge posteriorly ; its belly is of a 

 reddish-brown superiorly, and a dirty gray beneath, with its extremity almost black. The whole 



insect is thickly covered with down. In the latter part of 

 the summer the impregnated female is seen very busy about 

 horses, being now prepared to deposit her eggs. She ap- 

 proaches the horse, selects some part which he can reach 

 with his tongue, and which he is in the frequent habit of 

 licking; she balances herself for a moment, and then sud- 

 denly darting down, deposits an egg on one of the hairs, 

 which adheres by a glutinous substance that surrounds it. 

 She continues her labor with wonderful perseverance until 

 she has parted with fifty or a hundred eggs, and then having 

 exhausted herself, she slowly flies away, or drops at once 

 and dies. These esfors, taken into the stomach of the horse, 

 are hatched, the larvje being an inch long. These pass 

 through the whole length of the intestines, and are voided 

 with the excrement. They now dig into the earth, enter into the pupa state, and after lying 

 dormant for a time, burst from their prison, mount on their wings, and seek their mates. Of 

 the Horse-Fly, genus Tabanus, we have three noted species, the Black, Belted, and Lined, with 

 others, smaller and less notorious. 



THE MUSCIDJ5. 



This family includes an immense number of insects, twelve hundred species having been, it 

 is said, described by a naturalist in Europe. Of these the Common House-Fly, Musca domestica, 

 furnishes a familiar example. In the larva condition, some of them live in dung ; some, as the 

 Flesh-Fly, 3f. vomitoria, often called Meat-Fly, feed upon animal substances. The Cheese- 

 Hopper, Piophila casci, makes considerable leaps by bending its body into a loop and then 

 suddenly straightening it. Many of these larvae, which feed upon animal substances in a state 

 of decomposition, must be included among our greatest benefactors, as, by removing in a short 

 space of time, matters which, if left, would corrupt and fill the atmosphere with noxious vapors, 

 they prevent all the ill effects which these effluvia are known to produce upon animal life. So 

 rapidly do they perform this business, that Linnaeus calculated that the progeny of three Flesh- 

 Flies would devour the carcass of a horse almost as quickly as a lion. 



The larvae are soft footless grubs, frequently destitute of any distinct head. They are generally 

 produced from eggs laid by the parent in the midst of substances suited to their nourishment. 

 The habits of the perfect insects are various ; many attack men and animals and seek their 

 blood ; some live on the juices of flowers ; some inhabit filthy water and other foul liquids ; they 

 are endowed with a telescopic tail, through which they breathe by putting it to the surface while 

 thev are immersed in the water. 



THB BBEEZE-FLT. 



a, eggs of Breeze-Fly ; b, the same mag- 

 nified ; c, larva, or bot ; d, chrysalis ; e, per- 

 fect insect ; /', female depositing her eggs. 



