48 THE THORAX Uli TiiUXK. 



three primary rings, the first, or the one next the head 

 having the name of prothoraXy the second mesothorax^ 



MTEMICO, ONE OF THE SOCIAL ANTS. 



and the third metathorax ; in most insects, however, 

 there are apparent but two segments, the prothorax con- 

 stituting the first and the mesothorax and metathorax 

 the second ; to the former are attached the first pair of 

 legs, often denominated the arms, and to the latter 

 the remaining two pairs of legs, or legs proper, and 

 the one or two pairs of wings. 



Each of these three sections might be considered in 

 relation to a number of special parts, but we will desig- 

 nate only those of the prothorax, and then proceed to a 

 consideration of their appendages, the legs and wings. 



The prothorax consist commonly of two pieces ; the 

 shield or upper part, and the era or under part, a con- 

 tinuation of the shield under the body. The shield has 

 several plates or portions termed the apex, the part next 

 the head, the base, that next the abdomen, the border or 

 limb, and the disk or central part. 



Omitting the details of the second and third rings of 

 the thorax (mesothorax and metathorax), we are next to 

 consider the special organs of motion attached to it, ^. e., 

 the legs and wings. 



The legs of insects are among the most conspicuous 



