106 INSECTS DIAGRAM 6 



point, but these are the only movements which it can make. It 

 has no visible limbs, and does not eat. All the pupro of insects, 

 however, are not thus immoveable ; and there are some which 

 much resemble either the larva or the perfect insect. 



Imago state. After the chrysalis has remained motionless for 

 some time, the skin which envelopes it tears or splits, and the 

 perfect insect emerges in the form which it will henceforth retain. 

 It is the structure of the perfect insect which we are now about 

 to try to describe. 



The body of an insect (we may take a cockchafer as an ex- 

 ample) seems to be entirely composed of a definite number of 

 solid rings regularly arranged, and forming three very distinct 



Antenna of Antenna of 



cockchafer. weevil. 



Antenna of 

 moth. 



regions, the head, thorax, and abdomen. These rings, as also 

 those which form the limbs, are called segments. 



The head is provided with a mouth, antennae, and eyes. The 

 antennse are a kind of small horns which are found in many ar- 

 ticulated animals. They have very different shapes, as may be 

 seen by comparing those of a moth, a cockchafer, and a weevil. 

 In the moth or butterfly, they are formed of a great number of 

 very small joints placed end to end. In the cockchafer they are 

 formed of plates which seem to form a fan. In the weevil, the 

 antennas are elbowed at a right angle. Insects use their an- 

 tennro to feel the objects or the ground round them. 



The mouth differs much in different insects ; but it never 



