Fig. 54, Cimbex, Brischae and Zaddach. l.c. T. 2, Fig. 9.
Fig. 55. Julus (after Gervais).
Firstly, however, let me say a word as to the general Insect type. It may be described shortly as consisting of animals possessing a head, with mouth parts, eyes and antennæ; a many segmented body, with three pairs of legs on the segments immediately following the head; with, when mature, either one or two pairs of wings, generally with caudal appendages I will not now enter into a description of their internal anatomy. It will be seen that, except as regards the wings, Pl. [IV], Fig. 4, representing the larva of a small beetle named Sitaris, answers very well to this description. Many other Beetles are developed from larvæ closely resembling those of Meloë (Pl. [IV], Fig. 2), and Sitaris (Pl. [IV], Fig. 4); in fact—except those species the larvæ of which, as, for instance of the Weevils (Pl. [II], Fig. 6), are internal feeders, and do not require legs—we may say that the Coleoptera generally are derived from larvæ of this type.
I will now pass to a second order, the Neuroptera. Pl. [IV], Fig. 1, represents the larva of Chloëon, a species the metamorphoses of which I described some years ago in the Linnean Transactions,[60] and it is obvious that in essential points it closely resembles the form to which I have just alluded.
The Orthoptera, again, the order to which Grasshoppers, Crickets, Locusts, &c. belong, commence life in a similar condition; and the same may also be said of the Trichoptera.
The larvæ of Bees when they quit the egg are entirely legless, but in an earlier stage they possess well-marked rudiments of thoracic legs, showing, as it seems to me, that their apodal condition is an adaptation to their circumstances. Other Hymenopterous larvæ, those for example of Sirex (Fig. [9]), and of the Saw-flies (Fig. [50]) have well-developed thoracic legs.