INSKCTA. 
33 () 
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 iDublished ; for all practical 
purposes, however, the denominations already introduced may suffice. 
A second production relative to the same subject, Avhich 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 ai’e executed on a great 
scale, as are also those of a Memoir of Jurine, Sen. on the wings of 
the Hymenoptera, a work, like the preceding one, which is the result of 
infinite patience. 
As Insects inhabit all kinds of dwellings, they are provided with 
all sorts of locomotive organs, xvings and feet, which in several, act 
as fins. 
Ifiie wings are membranous, dry, elastic organs, usually diapha- 
nous, and attached to the sides of the back of the thorax : the first, 
when there rre four, or when they are unique, on those of its second 
segment, rnd the second on those of the following or of the meta- 
thorax. 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 advantage of the disposition and decussation of these nervures * 
in a systematic i)oint of view. The Libellulse, Apes, Vespae, 
Papiliones, &c., have four wings ; but those of the latter are covered 
with small scales, which at the first glance resemble dust, and give 
them the magnificent colours in which they are drest. They are 
easily removed with the finger, and that portion of the wing becomes 
transparent. By the aid of glasses we discover that these scales are 
of various figures, and implanted in the wing by means of a pedicle, 
arranged gradually and in series, like tiles on a roof. Before the 
superior wings of these Insects are two species of epaulettes — ptery- 
goda — which extend posteriorly along a portion of the back on which 
they are laid. The wings of some Insects remain straight, or are 
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 Scolopendrce, that which hears the 
two hooks, as an analogous division of the head. It seems that Knoch had distin- 
guished the epiinera by the names of scapulae and parapleuree, the post-pectus by 
that of acefabulum, while the mediopectus was his peristwthium. The first joint of 
the four posterior coxae, in most of the Coleoptera, forms a transverse plate, enclosed 
in the flanks, and is the piece, as far as I can judge, that he calls the ttiarinin. 
* See genet al observations on the Hymenoptera. 
