438 



ZOOLOGY. 



organs serving for aerial locomotion, a function which gives 

 to the entire class one of its most prominent characters ; 

 finally, on the kind of metamorphoses which these beings 

 undergo when young. Now, after what we have said else- 

 where respecting the essence of natural classification, it is 

 evident that it ought in consequence to be 

 in the modifications of the buccal apparatus, 

 of the wings, and of their mode of develop- 

 ment, that the zoologist should look for the 

 basis of a methodical distribution of these 

 animals. In fact, it is in this way that they 

 have come to divide them into a certain 

 number of orders, to which have been given 

 the names of coleoptera, ortkoptera, neu- 

 roptera, hymenoptera, lepidoptera, hemip- 

 tera, diptera, rhipiptera, anoptura, and thysanura. 



539. The coleoptera as well as the orthoptera and the 

 neuroptera, are formed to be. nourished on solid substances, 

 whether animal or vegetable, and are furnished for this pur- 

 pose with mandibles and jaws adapted for the division of this 

 kind of food (Fig. 434). They have two pairs of wings, but 

 those of the first pair are not adapted for flight, and consti- 

 tute a sort tf hard and horny bucklers called elytra (a, Fig. 

 426). 



Fig. 460.- Wimble 

 (Ptinus). 



Fig. 461. Scarabasns (or Alescus), 

 Sacred Beetle of the Egyptians. 



Fig. 462. Dermeste 

 du Lard ; Lard Insect. 



The wings of the second pair are, on the contrary, mem- 

 branous, transparent, and too long to be concealed under the 

 elytra without being folded across j sometimes they are alto- 



