MOTIONS OF INSECTS. 301 



(mlminicula), generally single, but in some instances 

 forked, looking- towards the anus, and usually placed 

 upon transverse ridges on the back of the abdomen, 

 but sometimes arming the sides or the margins of the 

 segments. By this simple contrivance, aided by new- 

 born vigour, when the time for its great clmnge is ar- 

 rived, the included prisoner of hope, if under ground, 

 pushes itself gradually upwards, till reaching the sur- 

 face its head and trunk emerge, when an opening in 

 the latter being- effected by its efforts, it escapes from 

 its confinement, and once more tastes the sweets of li- 

 berty and the joys of life. Those that are inclosed in 

 trees and spin a cocoon, are furnished with points on 

 the head, with which they make an opening in the for- 

 mer. The pupa of the great goat-moth {Bomhi/x Cos- 

 sus, F.) thus, by divers movements, keeps disengaging 

 itself from this envelope, till it arrives at a hole in the 

 tree which it had made when a caterpillar; when its, 

 anteiior part having emerged, it stops short, and so 

 escapes a fall that might destroy it. After some re- 

 pose, in consequence of very violent efforts, the pu- 

 parium opens, and it escapes from its prison''. ^ 



The insects of the Trichoptera order {Phr?/ganea^'Li.) 

 are quiescent when they^ first assume the pupa, but be- 

 come locomotive towards the close of their existence in 

 that state. Since they inhabit the water when they be- 

 come pupae. Providence has furnished them Avith the 

 means of quilting that fluid without injury, when they 

 are to exchange it for the air ; which in their winged 

 state is their proper sphere of action. I have before 



" Lyoncf, Trait, yinat. 15 — 



