Every one looking at a butterfly must have remarked its long horns, called _antennæ_,[4] which project from above the eyes, like jointed threads, thickening--in some {28} species gradually, in others suddenly--into a club or knob at the extremity; a peculiarity which, it will be remembered, was pointed out at the commencement, as a prominent mark of distinction between butterflies and moths. Very graceful appendages are these waving _antennæ_, and evidently of high importance to their owner; but still, their exact office or function is unknown, notwithstanding that many guesses and experiments have been made with a view of settling that question. Investigators have perhaps erred, by assuming at the outset that these antennæ _must_ be organs of some sense that we ourselves possess; whereas, I think that there is much evidence to show that insects are gifted with a certain subtle sense, for which we have no name, and of which we can have as little real idea, as we could have had of the faculty of sight, had all the world been born blind. For example; if you breed from the chrysalis a female Kentish Glory Moth, and then immediately take her--in a closed box, mind--out into her native woods, within a short space of time an actual crowd of male "Glories" come and fasten upon, or hover over, the prison-house of the coveted maiden. Without this magic attraction, you might walk in these same woods for a whole day and not see a single specimen, the Kentish Glory being generally reputed a very rare moth; while as many as some 120 males have been thus decoyed to their capture in a few hours, by the charms of a couple of lady "Glories," shut up in a box. [Illustration: V.] {29} Now, which of our five senses, I would ask--even if developed into extraordinary acuteness in the insect--would account for such an exhibition of clairvoyance as this? May not, then, this undiscovered sense, whatever may be its nature, reside in the antennæ? for it is a remarkable fact, that the very moths, such as the Eggers, the Emperor, the Kentish Glory, &c., which display the above-mentioned phenomenon most signally, have the _antennæ in the males_ amplified with numerous spreading branches, so as to present an unusually large sensitive surface. This seems to point to some connexion between those organs and the faculty of discovering the presence, and even the condition, of one of their own race, with more, perhaps, than a mile of distance, and the sides of a wooden box, intervening between themselves and their object.