ANTENNX, horn-like members placed on the head, and peculiar to Insects and Crustaceous Animnls. Their functions are not well understood, and have given rise to several different opinions among naturalists. The term is derived from the Latin ante, 'before.' in insects they are uniformly two in number ; but in crabs and lobsters there are more than two. They are connected with the head, always near the eyes, by means of a ball (buMus) and socket (torulus). They are composed of minute cylinders or rings successively added to each other, to the number of 30 in some butterflies, and thus forming a tube which inclomem nerve* for sensation, muscles for moving, ns well as air-pipes and cells.
The form of the antennae is exceedingly various, seine being simple and some feathered, clubbed, comb-shaped, in endless diem-silly. lit moths, the female is distinguished from the male by the antes nm being more simple. In some moths and beetles the antenum are very long compared with the length of the body, whereas in the house-fly, and some other two-winged flies, they are very short. Their length does not depend on the number of joints, for they may be long when composed of only three or four pieces, and short when composed of ten or more pieces.
With respect to the functions of the antennae, it is the most com mon opinion, sanctioned by such authorities as Linumus and Bergumun, that they are organs of touch, and are on that account often termed feelers ; "but,' as 3L Straus-Derckbeim justly remarks, "this con jecture is founded upon felts imperfectly investigated, if not altogether false. I have made numerous researches on this subject, and I have never been able to satisfy myself that insects examine objects by feeling them with their antenna. On the contrary, I have rarely observed these animals touch anything with these organs, and when this did happen, it appeared to be only by accident, and not nt all from design. Many insects, besides, have their antenna; so short, that they would be obliged to stand erect upon their heads in order to come at the bodies which they might thus wish to explore, and for this their feet are certainly much better adapted.
" Since," continues 3L Straus-Diirekhoim, " almost all Articulated Animals possessing a solid skin (peas) s)have antenme,whieh are furnished with nerves of an extraordinary thickness in proportion to their own size, them cannot remain a doubt that they are organs of some sense, and that too a very acute one.
" I have said that insects are proved, by observation, to be furnished with an organ of hearing. The solidity of the envelope of antenna; renders these organs well adapted to undergo the same vibrations as tho air, in the same manner as the strings of an zEolian harp vibrate and emit various sounds according as they are differently struck by the air. lit this view, however, we might infer that nature would have made entente:0 in the form of rods, consisting of a single piece, in order that they might be more susceptible of vibrations ; but it ought to be considered, that these organs would, by ouch a conformation, have been much exposed to breaking, while, in consequence of their jointed form, they have the advantage of regulating the degree of vibration at pleasure, as may indeed be observed when insects listen with atten tion; I mean, that the joints of the antenna perform the same funet ions as the chain of small bones in the chamber of the human inasmuch as they form a similar chain, and transmit the vibrations of the air to the auditory pulp." Professor llonwlorff of Abo in Finland, and other naturalists, though opposed to the views of Linmene and Bergmann, have adopted tho saute opinion, and regard the antennas as organs of hearing.
There is one other subject connected with the antennm which notice. The younger Iluber has attributed to ants the use of certain signs made with these organs, which he terms ' antenna' language,' underetood not only among ants themselves, but also among the aphidm, on which they depend for the excretion popularly termed honeydew. Tho motions of the !ultimate, however, to which he refers in proof of his views, do not, so far as we can judge, authorise its to conclude that they are used in the way of language, any more than " I have had," says he, "two Little Ant-Eaters or Fourmilliers, which were not larger than a squirrel : one was of a bright yellow colour, with it brown stripe on the back ; the other was a silvery-gray and darker on the back ; the hair of each was very soft and silky, a little crimped; the head was small and round, the nose long, gradually bending downwards to a point; it had no teeth, but a very long round tongue; the eyes were very small, round, and black; the legs rather short ; the fore-feet had only two claws on each, the exterior being much larger and stronger than the interior, which exactly filled the curve or hollow of the large one; the hind-feet had four claws of a moderate size; the tail was prehensile, longer than the body, thick at the base and tapering to the end, which, for 1101110 inches or; the under side, was bare. This little animal in Surinam is called Kissing-iland, as the inhabitants pretend that it will never eat, at least when caught, but that it only licks its paws, in the same manner as the bear ; that all trials to make it eat have proved in vain, and that it soon dies in confinement. When I got the first, 1 sent to the forest for a nest ol ants, and, during the interim, I put into its cage some eggs, honey, milk, and meat ; but it refused to tone); any of them. At length the ants' nest arrived, but the animal did not pay the slightest attention to it either. By the shape of he fore-paws, which resemble nippers, and differ very much from those of all the other different species ol ant-eaters, I thought that this little creature might perhaps live on the nymphet of wasps, &c. ; I therefore brought it a weeps' nest, and ther it pulled out with its nippers the nyuiplim from the next, and began tc eat them with the greatest eagerness, Kitting in the posture of a I showed this phenomenon to many of the Inhabitants, who all assured me that it was the first time they had ever known that species 01 animal to take any nonriehment. The ants with which i tried it were the large white termites, upon which fowls are fed here.
" As the natural history of this pretty little animal is not mucl to theorise in the same way upon the bills of nestling birds which are opened to receive food, or their wings which are opened and vibrated rapidly while they receive it. That there is nothing peculiar in this alleged antenna' language, so far as the aphides are concerned, any one who chooses may prove by taking a pin or a camel-hair pencil and gently touching the aphis, when it will eject the honey-dew as readily as in consequence of being touched with the antenwe of an ant. This we deem to be quite fatal to M. Huber'a conclusions.
(Insect M iscellanies,vol. iv., in the Library of Entertaining Knowledge.) ANTENNULARIA, a genus of Sertularian Zoophytes. [SEttru LARIAD.E.]