On diseases of the skin . be dependent uponthe same source, and to bear an accurate proportion to the degree ofdevelopment of the papillae. Thus, on the palms1 of the hands, wherethe papillae are large, the epidermis is thick ; while on the backs ofthose organs, or on the scalp, where the papillae are small, it is ex-ceedingly thin. Another character presented by the epidermis is also to be consi-dered as the consequence of its connection with and dependence on the 1 In an individual not exposed to much manual labor, I found the epidermis in thepalm of the hand to measure one-fourth of a line
On diseases of the skin . be dependent uponthe same source, and to bear an accurate proportion to the degree ofdevelopment of the papillae. Thus, on the palms1 of the hands, wherethe papillae are large, the epidermis is thick ; while on the backs ofthose organs, or on the scalp, where the papillae are small, it is ex-ceedingly thin. Another character presented by the epidermis is also to be consi-dered as the consequence of its connection with and dependence on the 1 In an individual not exposed to much manual labor, I found the epidermis in thepalm of the hand to measure one-fourth of a line in thickness. The horny coveringof the foot of the dog is formed by papilla? of unusually large size, and highly vas-cular. STRUCTURE OF THE EPIDERMIS. 47 derma—namely, the network of linear furrows, which every whereintersect each other, and trace out the surface into small polygonaland lozenge-shaped areas. These lines correspond with the folds ofthe derma produced by its movements, and are most numerous where Fig. those movements are greatest, as in the flexures, and on the convex-ities of joints. Some difference is perceived in the form of the areas,when examined in these two situations; thus, in the flexures of thejoints they are narrow and long, and, for the most part, lozenge-shaped in their figure, while on the convexities of joints, as upon theelbow and knee, the areas are large, and more nearly furrows of the epidermis admit of a division into two kinds,—namely, those which correspond with joints, and bear relation to themovements of the body and limbs, and those which belong especiallyto the movements of the skin. The first or larger kind are thosewhich are so perceptible on the flexures and convexities of joints, andon the palm of the hand and the sole of the foot. The latter orsmaller occupy the interspaces of the former, and those parts of thesurface where the furrows of articular motion have no plan of arrangement is as fo
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Keywords: ., bo, bookcentury1800, bookdecade1860, booksubjectskin, bookyear1865
