312 



Handbook of Nat it re-Study 



The Structure of Insects 



The insect body is made up of ring-like segments which are grown 

 together. These segments are divided into groups according to their use 

 and the organs which tliey bear. Thus the segments of an insect's body 

 are grouped into three regions, the head, the thorax and the abdomen. 

 The head bears the eyes, the antennae, and the mouth-parts. On each 

 side of the head of the adult insect may be seen the compound eyes; these 

 are so called, because they are made up of many small 

 eyes set together, much like the cells of the honeycomb. 

 These compound eyes are not found in larvae. In addi- 

 tion to the compound eyes, many adult insects possess 

 simple eyes; these are placed between the compound 

 eyes and are usually three in number. Often they 

 cannot be seen without the aid of a lens. 



The antennas or feelers are composed of many seg- 

 ments and are inserted in front of the eyes or between 

 them. They vary greatly in form. In some insects 

 they are mere threads; in others, like the silk- worm 

 moths, they are large, feather-like organs. 

 The mouth-parts of insects vary greatly in structure and in form, 

 being adapted to the life of the insect species to which they minister. 

 Some insects have jaws fitted for seizing their prey, others for chewing 



A part of the 



compound eye 



of an insect, 



enlarsed. 



Simple 



eye 



Ovipositor 



fc»t * Tars OS 



'To«-pad orlVitvillus 



Grasshopper, ivith the parts of the external anatomy named. 



