DERM

(Gr. Ij^fxcc, skin.) The true or organized layer of the tegumftntary covering of animals. It is composed of a close and irregular network of whitish fibres, consisting of condensed cellular ti ue, whence it is also termed " corium," and is every where traversed by capillary arteries and veins, absorbents and nerves; and, in the mammal i a, with the roots of the hairs and the ducts of the sudorific follicles: it is covered with the " rete mucosmn " and " epiderm." The derm is of considerable thickne in the rhinoceros, hippopotamus, elephant, .; whence the name " Pachyderm a," applied to the order containing these and allied quadrupeds. DERMAPTERANS, Derm apter a. (Gr.Se^//^, and a-rs^ev, a wing; skin-winged.) An order of insects dismembered from the Orthoptera of Latreille, and including those which have the elytra wholly coriaceous, and always horizontal; the two membranous w ings are folded longitudinally, and the tail is armed with a forceps. This order is represented by a single Linneean genus, — viz. Furjicula, or earwig; insects which are common in damp places, and often foimd in numbers under stones, and beneath the bark of trees: they do much damage in gardens by preying upon the fruit. The English common name, and also the French, " pierce-oreille," relate to a habit absurdly attributed to these insects of penetrating the ears. [s. 341]