HAIRS. 415 



and numerous lymphatics and nerves. In shaving, so 

 long as the razor keeps in the epidermis there is no bleed- 

 ing; but a deeper cut shows at once the vascularity of the 

 true skin. 



The outer surface of the corium is almost everywhere 

 raised into minute elevations, called the papillae, on which 

 the epidermis is moulded, so that its deep side presents pits 

 corresponding to the projections of the dermis. In Fig. 117 

 is a papilla of the corium containing a knot of blood-vessels, 

 supplied by the small artery,/, and having the blood carried 

 off from them by the two little veins, g g. Other papillae 

 contain no capillary loops but special organs connected 

 with nerve-fibres, and supposed to be concerned in the sense 

 of touch. On the palmar surface of the hand the dermic 

 papillae are especially well developed (as they are in most 

 parts where the sense of touch is acute) and are frequently 

 compound or branched at the tip. On the front of the 

 hand, they are arranged in rows; the epidermis fills up the 

 hollows between the papillae of the same row, but dips down 

 between adjacent rows, and thus are produced the epidermic 

 ridges seen on the palms. In many places the corium is 

 furrowed, as opposite the finger- joints and on the palm. 

 Elsewhere such furrows are commonly less marked, but 

 they exist over the whole skin. The epidermis closely 

 follows all the hollows, and thus they are made visible from 

 the surface. The wrinkles of old persons are due to the 

 absorption of subcutaneous fat and of other soft parts 

 beneath the skin, which, not shrinking itself at the same 

 rate, becomes thrown into folds. 



Hairs. Each hair is a long filament of epidermis devel- 

 oped on the top of a special dermic papilla, seated at the 

 bottom of a depression reaching down from the skm into the 

 tissue beneath and called the hair follicle. The portion of 

 a hair buried in the skin is called its root; this is succeeded 

 by a stem winch, in an uncut hair, tapers off to & point. The 

 stem is covered by a single layer of overlapping scales form- 

 ing the hair cuticle; the projecting edges of these scales 

 are directed towards the top of the hair. Beneath the hair 

 cuticle comes the cortex, made up of greatly elongated cells 



