410 DIPTERA. 



most curious. When the fly settles upon a lump of sugar or 

 other sweet object, it unbends its tongue, extends it, and the 

 broad knob-like end divides into two flat, muscular leaves (7), 

 which thus present a sucker-like surface, with which the fly laps 

 up liquid sweets. These two leaves are supported upon a 

 framework of tracheal tubes, which act as a set of springs 

 to open and shut the muscular leaves. In the preceding figure, 

 Mr. Emerton has faithfully represented these modified tracheae, 

 which end in hairs projecting externally. Thus the inside of 

 this broad fleshy expansion is rough like a rasp, and as Newport 

 states, "is easily employed by the insect in scraping or tearing- 

 delicate surfaces. It is by means of this curious structure that 

 the busy house-fly occasions much mischief to the covers of our 

 books, by scraping off the albuminous polish, and leaving tra- 

 cings of its depredations in the soiled and spotted 

 appearance which it occasions on them. It is 

 by means of these also that it teases us in the heat 

 of summer, when it alights on the hand or face 

 to sip the perspiration as it exudes from, and is 

 condensed upon, the skin." 



Every one notices that house-flies are most 

 abundant around barns in August and Septem- 

 ber, and it is in the ordure of stables that the 

 early stages of this insect are passed. N"o one 

 Fig. 331. has traced the transformations of this fly in this 

 country, but we copy from Bouche's work on the transforma- 

 tions of insects, the rather rude figures of the larva (Fig. 331), 

 and pnparium () of the Musca domestica of Europe, which is 

 supposed to 1)6 our species. Bouche states that the larva is 

 cylindrical, rounded posteriorly, smooth and shining, fleshy, 

 and yellowish white, and is four lines long. The puparium is 

 dark reddish brown, and three lines in length. It remains in 

 the pupa state from eight to fourteen days. In Europe it is 

 pre} r ed upon by minute ichneumon flies (Chalcids). Idia 

 Biyoti, according to Coqucrel and Mondiere, produces a disease 

 in the natives of Senegal, probably by ovipositing on the skin, 

 thus giving rise to hard red fluctuating tumors, in which the 

 larva of this fly resides. 



The species of the genus Anthomyia, seen about flowers, in 



