I [ 383 ] XXXII. Further Remarks on the Organs of the Antennm of Insects, described in a Faper published in the ' Transactions of the Linnean Society,' vol. xxii. ^j. 155. By J. Braxton Hicks, Esq., M.J). Lond., F.L.S., ^c. Read May 5th, 1859. On the 2nd of June, 1857, 1 read a paper before this Society, describing some " peculiar structures in the Antenna} of Insects," which was published in the ' Transactions,' vol. xxii. p. 155 ; since which time I have extended my inquiries among the different tribes, the results of which I have now the pleasure of laying before you. But before doing so, it seems to me that it would be well to give an outline of what had been previously accom-plished towards the determination of the structiu-e and uses of the antennae, and of the various opinions founded upon those researches. I shall first of all quote Burmeister, who, in his ' Manual of Entomology,' translated by Shuckard, 1836, p. 295, § 195, says, " But as insects doubtlessly hear — as some, for example the Cicada, Grasshopper and May Beetle, &c., produce a peciiliar sound, which serves to attract the attention of the female — they must evidently be provided with an oi'gan of hearing, which is either very recondite, or referred to organs whose form does not evince their function. The antennae are doubtlessly of this class ; and, indeed, Sulzer, Scarpa, Schneider, Bockhausen, Reaumur, and Bonsdorff considered them organs of hearing. That they are not organs of touch is proved, anatomically, by their hard, horny upper sui'face, and physiologically by the observation that they never use them as such, this function being exercised by other organs, \dz. the palpi. Besides, the analogy of the Crabs, in which it is well known that the organ of hearing lies at the base of the larger antennae, speaks in favour of the opinion of their being in general organs of hearing. If after this hint we look to the insertion of the antennae, we likewise detect here a soft articulating membrane, which lies exposed, and which is rendered tense by the motion of the antennae. This membrane, beneath which the nerve of the antenna runs, might, without much inconsistency, be explained as the drum of the ear, and thus would the antennae be transformed helices, which, as very moveable pai-ts, would receive the vibra-tions of the an-caused by sound, and act as conductors to it. "Whoever has observed a tranquilly-proceeding Capricorn Beetle which is suddenly sui-prised by a loud sound, will have seen how immoveably outward it spreads its antennae, and holds them poiTcct, as it were with great attention, as long as it listens, and how carelessly the insect proceeds in its course when it conceives that no danger threatens it fi-om the vmusual noise. Carus, Straus-Diirckheim, and Oken are of the same opinion, which I have entertained for years, and endeavoured to confirm myseK in by numerous experiments." § 19G. " Much more doubt and uncertainty attend the observations and opinions upon the organ of smeU of insects. Reaiunur, Lyonet, and several modern French anatomists consider the antennae as such ; but I would ask, Avith what right ? The hard,
BioStor
