INSECTA. 233 



and by the extract published by the author in the article 

 Insectes of the Diet. Class. d'Histoire Naturelle. Before 

 we can adopt his nomenclature, and apply it 'generally, we 

 must wait until his work and the figures which accompany it 

 are published; for all practical purposes, however, the de- 

 nominations already introduced may suffice. A second pro- 

 duction relative to the same subject, which both justice and 

 friendship here compel me to notice, is that of M. Chabrier 

 on the flight of Insects. It forms part of the Mem. du Mus. 

 d'Hist. Nat., but is sold separately. The figures are exe- 

 cuted on a great scale, as are also those of a Memoir of Jurine, 

 Sen. on the wings of the Hymenoptera, a work, like the pre- 

 ceding one, which is the result of infinite patience. 



As Insects inhabit all kinds of dwellings, they are provided 

 with all sorts of locomotive organs, wings and feet, which in 

 several, act as fins. 



The wings are membranous, dry, elastic organs, usually 

 diaphanous, and attached to the sides of the back of the tho- 

 rax: the first, when there are four, or when they are unique, 

 on those of its second segment, and the second on those of the 

 following or of the metathorax. They are composed of two 

 membranes laid one on the other, and are traversed in various 

 directions by more or less numerous nervures, which are so 

 many tracheal tubes, now forming a network, and then simple 

 veins. A celebrated naturalist, Jurine, Sen., has taken ad- 

 vantage of the disposition and decussation of these nervures(l) 

 in a systematic point of view. The Libellulse, Apes, Vespse, 

 Papiliones, &c., have four wings; but those of the latter are 



senting the lower lip, is not attached to the head, but to the membrane which 

 unites it with the thorax, and thus also we find that the two medullary cords form 

 two contiguous ganglions under the mouth. In accordance with these views, we 

 consider the first segment of the body of the Scolopendrse, that which bears the 

 two hooks, as an analogous division of the head. It seems that Knoch had distin- 

 guished the epimera by the names of scapulas and parapleuras; the post-pectus by 

 that of acetabulum, while the mediopectus was his peristcethium. The first joint of 

 the four posterior coxs, in most of the Coleoptera, forms a transverse plate en- 

 closed in the flanks, and is the piece, as far as I can judge, that he calls the mcerium. 

 (1) See general observations on the Hymenoptera. 

 Vol III. 2E 



