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.
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.
Whilst writing this, the current number of the "Entomologist's Weekly Intelligencer" has arrived, and I there read that Dr. Clemmens, an American naturalist, has been lately experimenting on the antennæ of some large American moths, for the purpose of gaining some information as to their function. The article, though very interesting, is too long for quotation here; but it appears that with the moths in question, a deprivation of the whole, or even part of the antennæ, interferes with, or entirely annihilates the power { 30} of flight, so that the creature when thus shorn, but not otherwise injured, if thrown into the air seems to have no idea of using his wings properly, but with a purposeless flutter tumbles headlong to the earth. Still this merely goes to prove that the antennæ are the instruments of some important sense, one of whose uses is to guide the creature's flight; but as many wingless insects have large antennæ, this evidently is not their only function.