44 



INTRUDUCTION TO ZOOLOGY. 



The foot consists of two 

 pads tliicklj' beset with 

 minute liuirs, and two 

 hooks. No tliorouf;"hly sat- 

 isfactory exiilauation lias 

 been given of how a tiy 

 sticks to a vertical surface 

 of g'lass. 



FOOT OF TLY. 



The wing of any insect is 

 conipcjsed of \' e i n s , and 

 spaces l)(iuuded b}- veins. 

 These spaces are called cells. 

 The large vein forming tlie 

 front margin of the wing is 

 called the costal vein. The 

 vein marked 1 is the auxili- 

 ary vein ; 2, IS, 4, .'i. and (i are 

 the first, seciinil. third, 

 fourth, and fifth longitudi- 

 nal veins. The sliort cross- 

 vein lietween 4 and Sis the 

 miildle transverse vein ; the 

 short vein between 5 and 6 

 is till' Idnder transverse 

 vein. The cells A, hi, and 



C are called the first, second, and third costal cells: D is the mar- 

 ginal <'ell: E is the sub-marginal cell; F, K, and 11 are the first, 

 second, ami third posterior cells; G is the disc;il cell ; If is the lirst, 

 or large, basal cell. The cells a.nd veins of the win.t;- are of the 

 greatest ii.i]]orta,nce in ileterniining the fiunilies and species of 

 llii's. The veins of a. Ily's wing nuiy be bcmuilogized with the veins 

 ot the wing of atmii.st a,ny other insect. 



WING OP' FLT. 



