STRUCTURE OP THE SKIN. 
47 
(fig. 7, i i) y which, are commonly arranged in rows; of these, 
some are organs of touch, being furnished with sensory nerves 
that end upon a peculiar cushion-like organ in their interior 
(§ 490); hut into others no nerves can he traced, so that, 
as these are copiously supplied with hlood-vessels, it is pro¬ 
bable that they minister to the -nutrition of the epidermis. 
/ 
Fig. 7.—Vertical Section oe the Skin, 
Showing the different structures which it contains. A, Epidermis ; a a, its outer 
surface ; a — b, its horny layer; b—c its inner soft layer, dipping down into the 
hollow between the papillae; B, Cutis; d, arterial twig supplying its vascular 
papillae; e e, perspiratory glandulae; f, cluster of fat-cells ; g g, perspiratory duct, 
traversing the true skin; h, its continuation through the epidermis; i i, tactile 
papillae, with their nerves. 
This is the more probable from the fact that we find these 
vascular papillae very large and full of blood-vessels in the 
interior of corns,-warts, and other such productions, formed 
by a “ hypertrophy ” or over-nutrition of the epidermis in 
particular spots; and also in situations in which the ordinary 
epidermis is very thick, as it is on the black pads of the foot 
of the dog or cat. And a highly vascular structure of the 
