﻿PARTS OF AN INSECT. 59 



tached to the under side of the thorax, while the wings 

 are attached to the upper side thereof. 



thorctx. 



Fig. 53.— Head, having mouth-parts, antenna?, compound eyes, c; and simple eyes, «. 



Thorax, having legs and wings. 



Abdomen, never having legs or wings, but having certain appendages at the extremity. 



57. The wings of insects are never more than four in 

 number, and these are arranged in two pairs. 



The group of insects to which the house-fij belongs has 

 but two wings, or a single pair, and in this group (and other 

 groups of insects as well) there are some which have no 

 wings. 



The wings are very different in shape and structure in 



distinct kinds of insects. In the common fly they are 



quite small, and transparent. In the butterflies they are 



large and broad, and are covered with minute scales which 



rub off on the fingers like dust. In the dragon-fly the 



wings are long and narrow. 

 4 



