So infinite is the variety displayed in the disposition, structure, and ornaments of the wings of insects, that only to enumerate them would fill many pages; I must leave this subject to be further pursued by the reader, contenting myself with presenting him with the view of a wing of the hemerobius perla, as it appears under the microscope. The insect to which it belongs, has acquired the name of hemerobius, from the shortness of its life, as it seldom lives more than two or three days in the fly state. Linnæus has placed it in his fourth class, among those insects which have four transparent wings and no sting. The body of the insect is of a fine green colour; the eyes appear like two delicate beads of burnished gold, whence it is by many called the golden eye. The wings are delicate and elegant, nearly of a length, and exactly similar; they are composed of a beautiful thin transparent membrane, furnished with slender fine ribs, regularly and elegantly disposed, adorned with hairs, and slightly tinged with green. Fig. 1. Plate XV. exhibits its magnified appearance; Fig. 2. the natural size. OF THE WINGS OF MOTHS AND BUTTERFLIES. The wings of these insects are mostly farinaceous, being covered with a fine dust, which renders them opake, and produces those beautiful and variegated colours by which they are so richly adorned, and so profusely decked. If this be wiped off, you find the remaining part, or naked wing, to consist of a number of ribs, like those in the leaves of plants; but of a crustaceous or talcy nature; the largest rib runs along and fortifies the exterior edge of the wing; the interior edge is strengthened by a smaller vessel or rib. The ribs are all hollow, by which means the wing, though comparatively large, is very light. The substance between the ribs, and which constitutes the body of the wing, resembles talc,[57] surprizingly thin and transparent; as this is extremely tender, one use of the scales may be to protect it from injuries. When the moth emerges from the chrysalis, the wings are soft and thick, and if they be examined in that state, will be found to consist of two membranes, that may be raised up and separated, by blowing between them with a small tube: the ribs lie between these membranes. You may with the assistance of glasses discover certain strait and circular rows of extremely minute holes, running from rib to rib, or forming figures in the intermediate spaces, which seem to answer to the figures and variegations on the complete wing, and are probably the sockets for the stalks or stems of the small scales. [57] As the author’s idea of this substance being of the nature of talc, does not appear correct, and I cannot find that entomologists are agreed in the definition of it, I shall just give the following extract on the subject from the Cyclopœdia by Rees, and submit the decision to the reader.