48 MEMBERS OF INSECTS. 



The mid legs, or second pair, are jointed with the same 

 pieces in the hind corselet. 



Each leg may be considered as made up of four 

 principal pieces the haunch, the thigh, the shank, 

 and the foot enclosed in a horny or membranous 

 skin, containing the necessary muscles for moving the 

 joints. 



The haunch ( ! ) is various in form, being short and 

 small in most beetles, while it is large in wasps and 

 grasshoppers. In lady-birds it is round ; in cock- 

 roaches it is flat. It is made up of three pieces ( 2 ), two 

 next the corselet working in the socket ( 3 ), and the 

 third ( 4 ) jointed to the thigh, but apparently without 

 independent motion. 



The thigh ( 5 ) is the second principal piece, and is 

 always comparatively long and generally bulged, but 

 flat. It can only be moved backwards and forwards 

 and not sideways. In leaping insects, and in those 

 which dig and burrow, the thigh is always long, strong, 

 and muscular. 



The shank ( 6 ) is the third principal piece of the leg, 

 and is generally flat and about the same length as 

 the thigh, but more slender. In the hind legs of 

 swimming insects, the shank is often fringed. Upon 

 the upper end and sometimes the middle, moveable 

 spurs ( 7 ) are frequently jointed or fixed. 



The foot ( 8 ) is the fourth principal piece, with which 

 the leg ends. It is composed of five smaller pieces in 

 a great number of species, but in some cases only from 

 one to four, and in others, the number varies in the 

 several pairs of legs on the same insect. Two muscles, 

 one above and one below, have been detected in each 

 of these pieces. 



(1) In Latin, Coxa. 



(2) In Latin, Trochantina and Rotula. 

 (3) In Latin, Acetabulum. (4) In Latin, Trochanter. 



(5) In Latin, Femur. (6) In Latin, Tibia. 



(7) In Latin, Calcaria. (8) In Latin, Tarsus. 



