336 



THH REASON WHY. 



1 They hall lie down in the dust ; and the worms shall cover them." JOB xtr 



1320. Why have beetles hard horny iving-cases ? 



Because they live underground, or in holes excavate. i in wood, 

 &c. If, therefore, their wings were not protected by a hard and 

 firm covering, they would be constantly liable to destruction from 

 the movement of the insect within hard and rough bodies. 



Fig. 83. STAG-BEETLE, SHOWING IT 



The elytra, or scaly wings of the genus of scaraboms, or beetle, furnish an 

 example of this kind. The truo wing of tho animal is a light, transparent 

 membrane, finer than the finest gauze, and not unlike it. It is also, when 

 expanded, in proportion to the siac of the animal, very large. In order to 

 protect this delicate structure, and, perhaps, also to preserve it in a due state (il 

 suppleness and humidity, a strong, hard case is given to it, in the shapo of the 

 horny wing which we call the elytron. "When the animal is at rest, the gauze 

 wings lie folded up under this impenetrable shield. When the beetle prepares 

 for flying, he raises the integument, and spreads out his thin membrane to the 

 air. And it cannot 4je observed without admiration, what a tissue of cordage, 

 *. . of muscular tendons, must run in various and complicated, but determinate 

 dlfeottons, afdng this fine surface, iu order to enable th'e animal, either to gathw 



