338 NATURAL THEOLOGY. 



transparent membrane, finer than the finest gauze, 

 and not unhke 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 supple- 

 ness and humidity, a strong, hard case is given 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. And it cannot be oJ?served without ad- 

 miration, what a tissue of cordage, i. e, of muscu- 

 lar tendons, must run in various and complicated, 

 but determinate directions, along this fine surlace, 

 in order to enable the animal, eiiher to gather it 

 up into a certain precise form, whenever it desires 

 to place its wings under the shelter which nature 

 hath given to them ; or to expand again their folds 

 when wanted for action. 



In some insects the elytra cover the whole 

 body •,''^ in others, half; in others only a s ..all part 

 of it -^^ but in all,'" they completely hide and cover 

 the true wings. Also, 



''^ From this circumstance beetles (tlie tribe of insects to which 

 the above description applies) have received the name of Coleop^ 

 tera, from two Greek words si^^nifying sheath and loing. 



^^ A tribe of insects called the Brachelytra (or SiOphylinus o( 

 Linnaeus) possess wing cases of this description. 



80 These are exceptions. In the genera Motcrchvs, Silaris, (and 

 others might be enumerated among the beetle tribe,) the wing 

 uases are small and narrow, and leave the wings exposed. The 



