ORDER DIPTERA. 



119 



when covered with perspiration, it unbends its proboscis, 

 extends it, and the broad knob-like end divides into two 



FIG. 137. Head and proboscis of the blow-fly, e, eye; c. epicranium; bp. basi- 

 proboscis; p, maxillary palpus; pr, chitinous ridges uniting with the rudimen- 

 tary maxilla; Ip, lower labial plate; mp, medi-, dp, disti-proboscis. After 

 Kraepelin. 



flat, muscular leaves (Fig. 138, B, /), which thus form a 

 broad sucker-like surface, with which the fly laps up 



FIG. 13*. Proboscis of the house-fly. A, right-side view; B, view of the same from 

 above; C, semi tubes of its false tracheae; E, a tooth; F, arrangement of teeth 

 between roots of false tracheae; D, two of the false tracheae with wrinkled 

 membrane between. In A and B: I, labellum; o, operculum; p, palps; /, ful- 

 crum ; m, mentum. Magnified. After McCloskie. 



liquid sweets, or any matter which seems good to the fly's 

 mind. 



The two flaps at the end of the proboscis are supported 

 upon a framework of strong but delicate rods which act as 

 a set of springs to open and shut the broad flaps. The in- 

 side of this broad, fleshy expansion is rough, like a rasp, 

 and, as "Newport states, "is easily employed by the insect 



