THE CORIUM OR GTJTIS VEEA. 423 



the more does it grow, and the thicker and more horny 

 does it become ; for it serves as well to protect the sen- 

 sitive and vascular cutis from injury from without, as to 

 limit the evaporation of fluid from the blood-vessels. The 

 adaptation of the epidermis to the latter purposes may be 

 well shown by exposing to the air two dead hands or feet, 

 of which one has its epidermis perfect, and the other is 

 deprived of it ; in a day, the skin of the latter will become 

 brown, dry, and horn-like, while that of the former will 

 almost retain its natural moisture. 



Cutis vera. The corium or cutis, which rests upon a layer 

 of adipose and cellular tissue of varying thickness, is a 

 dense and tough, but yielding and highly elastic structure, 

 composed of fasciculi of fibro- cellular tissue, interwoven 

 in all directions, and forming, by their interlacements, 

 numerous spaces or areolse. These areolse are large in 

 the deeper layers of the cutis, and are there usually filled 

 with little masses of fat (fig. 105) : but, in the more super- 

 ficial parts, they are exceedingly small or entirely oblite- 

 rated. 



By means of its toughness, flexibility, and elasticity, the 

 skin is eminently qualified to serve as the general integu- 

 ment of the body, for defending the internal parts from 

 external violence, and readily yielding and adapting itself 

 to their various movements and changes of position. But, 

 from the abundant supply of sensitive nerve-fibres which 

 it receives, it is enabled to fulfil a not less important pur- 

 pose in serving as the principal organ of the sense of 

 touch. The entire surface of the skin is extremely sen- 

 sitive, but its tactile properties are due chiefly to the 

 abundant papillae with which it is studded. These papillae 

 are conical elevations of the corium, with a single or 

 divided free extremity, more prominent and more densely 

 set at some parts than at others (figs. 103 and 104). The 

 parts on which they are most abundant and most prominent 

 are the palmar surface of the hands and fingers, and the 



