336 



THE SEASON WHY. 



" They shall lie down in the dust ; and the worms shall cover them." JOB xxi 



1320. Why have beetles hard horny wing-cases ? 



Because they live underground, or in holes excavated 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. 



Pig. 83. STAG-BEETLE, SHOWING ITS WINGS UNFOLDED, AND THE WI3VO- 

 CASES OPEN. 



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

 example of this kind. The true wing of the animal is a light, transparent 

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

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

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

 suppleness and humidity, a strong, hard case is giv^en to it, in the shape 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. Aud it cannot be observed without admiration, what a tissue of cordage, 

 i. <9. of muscular tendons, must run in various and complicated, but determinate 

 directions, along this fine surface, in order to enable the auimal, either to gather 



