WINGS OF INSECTS. 49 



The most remarkable part of the foot, is the tip 



Eiece termed the claw ( ! ), which is wanting in the fore- 

 ;gs of some butterflies and other species. Each foot 

 has usually two claws, but in some insects there is 

 only one, and in others, there are four and even six 

 on one foot. The claws are very various in form 

 according to the uses intended. 



In the two-winged flies there are, between the 

 clawsjfrom two to three thin plates ( 2 ), outwardly convex 

 and toothed like a comb, and used for cleaning the 

 body and wings. At the base also are suckers, or, 

 as Mr. Blackwall thinks, spunges, containing a sort of 

 glue, which enable flies and other insects to walk up 

 glass against gravity. 



The leg of an insect, a, the haunch ; b, the thigh ; c, the 

 shank, with a forked spur j d, the foot, with five joints. 



The Wings in Insects. 



The wings in insects are four, sometimes two, in 

 number, and are uniformly jointed upon the upper 



(1) In Latin, Unguis. (2) In Latin, Pectines. 



