62 COLEOPTERA, OR BEETLES. 



mity of the organ is capable of folding inwards in a 

 most ingenious manner, when the insect, reposing 

 from its flight, consigns its wings to the protection of 

 its elytra. The apical portion of the wing is also 

 furnished with a few radiating veins, of less thickness 

 than those by which the extension of the lower part 

 of the organ is effected. Although the membranous 

 wings are of course considerably larger than the 

 elytra, they often seem quite inadequate to support 

 the bulky body of the Beetle in the air, and the flight 

 of most of these insects is in consequence rather 

 heavy, and exhibits none of those graceful evolutions 

 and rapid turns which render the flight of those of 

 some other orders so elegant and interesting. Never- 

 theless these organs are generally sufficiently powerful 

 to carry their owners along in a rapid, although some- 

 what headlong manner; the nervures of the basal 

 portion of the wing are very strong, and the extremity 

 when extended usually takes a downward direction, 

 so as to render the lower surface of the wing slightly 

 concave, an arrangement which necessarily increases 

 the power of the stroke. 



The back of the abdomen in all cases when it is 

 protected by the elytra, is covered with a soft and 

 flexible skin, an arrangement which appears to serve 

 the double purpose of giving a soft receptacle for the 

 folded wings, and of enabling the part to perform 

 those movements of contraction and expansion neces- 

 sary for the function of respiration, which would 

 otherwise be prevented by the comparative immo- 

 bility of the horny plates of the belly. 



As the first and perhaps the most characteristic 

 order of the Mandibulate Insects, we naturally expect 

 to find the mouths of the Coleoptera exhibiting the 



