Insect miscellanies / [Anon].

Date:
1832
Catalogue details

Licence: Public Domain Mark

Credit: Insect miscellanies / [Anon]. Source: Wellcome Collection.

    31/452 (page 9)
    \ SENSE OF TOUCH. ie | beetle ( Timarcha tenebricosa, MrcErie), this struc- ture of the feet is very obvious without the aid of a glass, which is required in observing the palms of the two-winged flies ( Diptera). In some other beetles, again, whose horny covering would seem to preclude them from possessing the means of touch over the surface of their body like the softer animals, and which even have their legs equally horny and stiff, we may observe, that a beautiful pro- vision is made for the sense of touch in a long, many- jointed, flexible claw at the termination of the foot. This is particularly remarkable in the common dung beetle (Geotrupes stercorarius), in which the flexibi- lity and easy motion of the jointed claw contrasts strikingly with the apparently awkward stiffness of the other joints, and indeed of the whole body. : According to the greater number of naturalists, however, the two chief organs of touch in insects are the antenne and palpi, both of which have been in popular language termed feelers. Latreille calls the palpi antennules.* Leaving the antenne to be dis- cussed in our chapter on Hearing, we shall only at present attend to the palpi, which are usually four in number. ‘These organs are small and gene- rally cylindrical, consisting of from one to six joints, one palpus being implanted in each of the two lower jaws, and the remaining two being attached to the lower lip, as exhibited in p. 43, fig. a. ‘The former, or upper pair, are, in most cases, a joint longer than the under, so as that they may all four, when bent down, reach to the ground at the same time. They are most commonly smooth, and end in a softish point ; but in some cases they are covered with hair (Copris, Cicindela, &c.) The only organs, in the higher animals, which seem analogous to these, are the whiskers ( Vibrisse) in the cat, the seal, and the night- * Régne Animal, iv, 301, edit. 1829.