INTfiODUCTIOIf. 



The wings, as already stated above, are membranous, divided by 

 nervures into irregular spaces or cells which in the tore wing are 

 never more than twenty in number, and in the hind wing fifteen. 



Fie. 9.— Hind leg of Salius aureosericeus. a, coxa; b, trochanter; c, fennir; 

 d tibia; c, tibial calcaria; /, tarsus; ff-l, joints of tarsus; m, claws; 

 n, pulvillus. 



-p\„ 10. Fore wing, a, anterior margin ; b, apical margin ; c, posterior 



margin ; d, postcostal nervure ; e, externo-medial nervure ; /, anal 

 nervure ; a, radial nervure; k, cubital nervure; i, discoidal nervure; 

 m n 0, let, 2nd, and 3rd transverse cubital nervures ; p, g, 1st and 2nd 

 recurrent nervures ; u, basal or medial nervure; v, w, 1st and 2nd trans- 

 verse subbasal, or submedial nervures: 1, stigma; 2, radial cell; 3, 4, 5, 

 and 6, cubital cells; 7, 8, 9, discoidal cells; 10, costal cell; 11, basal or 

 medial cell ; 12, 13, subbasal or submedial cells ; 14, apical cell ; 15, anal 



cell. . ^ 



■p\a 11. Hind wing, a, anterior or costal margin; o, postcostal nervure; 



c medial nervure ; d, anal nervure ; e, radial nervure ; /, cubital nervure ; 



a discoidal nervure; h, transverse anal nervure; k, anal lobe ; I, transverse 



cubital nervure: 1, site of tlie hamuli or little hooks which catch ou to 



the fore wing during flight; 2, costal cell; 3, radial cell; 4, medial cell; 



5, anal cell ; 6, cubital cell ; 7, discoidal cell. 

 Fig. 12. — Abdomen, $ . a, a}, c?, c?, a*, a^, dorsal segments ; b, 6\ b^, b^, b\ ¥, 



ventral segments. 



The winged Hymenoptera are, as a rule, capable of swift and 

 sustained flight. For this purpose they possess a wonderful 

 arrangement (one of the most beautiful in nature) for linking 



