410 



DIPTEKA. 



most envious. 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 (/), 

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

 laps up liquid sweets. These two leaves are supported upon a 

 framework of chitinous rods, which act as a set of springs to 

 open and shut the muscular leaves. 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 trac- 

 ings of its depre- 

 dations in the soil- 

 ed and spotted ap- 

 pearance which it 

 occasions on them." 

 The house-fly 

 breeds in August 

 about stables. The 

 s are deposited 



in horse-dung. The larva (Fig. 331*) hatches twenty-four 

 hours after the eggs are laid ; it moults twice, and in about 

 a week pupates, and in six or seven days more the fly 

 appears. In Europe it is infested by minute Chalcids. 



Id! a Hi got i, according to Coquerel 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 



* Fig. 3ol, A, larva of Mwa domcstica, just hatched, showing the distribu- 

 tion of the two main tracheae, and the anterior and posterior commissures 

 (a, a), dorsal view. B, the larva in the second stage; sp, spiracle. C, spiracle 

 enlarged. F, head of the same larva, enlarged ; 6Z, labrum (?); mil, mandibles; 

 mx, maxillae ; at, antennae. E, a terminal spiracle much enlarged. D, pupa- 

 rium ; sp, prothoracic spiracle. All the figures much enlarged. 



