STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 9 



jointed beak, the modified labium. The labrum closes the base of the 

 groove (Fig. 14). 



I li h 



Fig. II. — Mouth-parts of female mosquito (Culex pipiens). A, Dorsal aspect; 

 B, transverse section; C, extremity of maxilla; D, extremity of labrum-epi- 

 pharynx; a., antenna; e., compound eye; h., hypopharynx; I., labrum-epipharynx; 

 li., labium; m., mandible; mx., maxilla; p-, maxillary palpus. {After Folsom and 

 Dimmock.) 



Fig. 12. — Mouth-parts of the house-fly (Musca domestica). lb., Labrum; tnx.p., 

 maxillary palpi; li., labium; la., labellum. {After Kellogg.) 



Mouth-parts of the Butterfly. — The long sucking tube is composed of 

 the two maxillae joined together, while the other mouth-parts are 

 rudimentary (Fig. 15). 



