The Wings of Insects

The determination of the homology of the wing-veins of the Coleoptera is a difficult problem, owing to the greatly modified structure of the wings. Not only do the wings differ in structure from those of any other order of insects, but the two pairs of wings are modified in different ways. The fore wings, or elytra, have lost their flight-function, and have become thickened protective organs; while the hind wings are, in most cases, transversely folded, which has resulted in a great modification of the courses of the veins and in the formation of secondary vein-like thickenings of the wing. So different is the structure of the elytra from that usually characteristic of wings that Meinert 1 was led to believe that they were not wings, but greatly enlarged paraptera of the mesothorax; and unfortunately this view was adopted by the senior writer in his Manualfor thie Study of Insects. We have, therefore, two questions before us: first, Are the elytra modified wings, or not? and, second, What are the homologies of the wingveins ? The reasons in support of Meinert's view are the following: the difference in the structure of elytra from that of wings; the fact that in the Lepidoptera the paraptera of the mesothorax often bear a striking resemblance to elytra (this can be well seen by removing the scales from the paraptera, or patagia, as they are termed, of a sphinx moth); and the fact that in many Coleoptera (e.g., Dy/isczis) what appear to be rudiments of the fore wings exist beneath the elytra. The argument based on the thickened structure of the elytra loses its force when we consider the more or less elytra-like