590 EXTERNAL ANATOMY OF INSECTS. 
VI. Organs of Motion. We are next to consider those 
organs attached to the trunk of insects which are instru- 
ments of motion. These are principally those by which 
they are transported through the az7, and those by which 
they move on the earth or in the water—their wings 
and their Jegs. I shall begin with the first, the wings*. 
These are not formed precisely after any type at present 
discovered in vertebrate animals: in some respects they 
have an analogy to those of birds; in others, to the 
dorsal fins of fishes: but, perhaps, altogether they ap- 
proach the nearest to those of the dragon or flying-lizard 
(Draco volans), which do not, as in birds, replace the 
fore-legs, are kept expanded by diverging bony rays, 
and are connected with the hind-legs*. As the Divine 
Creator appears in his works to proceed gradually from 
one type of structure to another, it has been supposed 
by a learned physiologist of our own country, that in 
winged insects, four of the legs of the Decapod Crustacea 
are represented by the four wings?: this opinion, how- 
ever, is not yet fully proved; a remark which may also be 
the work here quoted, M. Latreille also speaks of these pseud- 
elytra, as I would call them, as appendages of the mesothorax: but 
whoever consults Mr. Bauer's admirable figures of Xenos Peckii 
(Linn. Trans. xi. t. ix.), and is aware of the unimpeached: and 
minute accuracy of that admirable microscopic artist, will be con- 
vinced that they belong to the anterior legs, and consequently to 
the prothorax. 
* Prate X. and Prate XXVIII. Fic. 18—23. 
b Chabrier, Analyse, &c. 27. 
° N. Dict. d’ Hist. Nat. ix. 568. We have seen above (p. 575—.) 
that the wings of insects are connected with their legs by the scapula 
and parapleura. 
4 MacLeay, Hor. Entomolog. 413—. M. MacLeay’s opinion seems 
to receive some confirmation from a circumstance overlooked when 
the /arve of insects were treated of above (p. 130—), and to which 
