CHAP. XVII.] 



THE SKIN. 



191 



The cutis vera is often described as consisting of two layers, 

 a superficial or papillary layer, and a deeper or reticular layer. 



The surface of the superficial or papillary layer is increased 

 by protrusions in the form of small conical elevations, called 

 papillae, and whence this layer derives its name. These papillae 

 contain for the most part looped blood-vessels, but they also con- 

 tain the terminations of medullated nerve-fibres in the shape of 

 little bodies, called tactile corpuscles. 



The papillae seem chiefly to exist for the purpose of giving 

 the skin its sense of touch, being always well developed where 



FIG. 111. SECTION OF SKIN SHOWING Two PAPILLA: AND DEEPER LAYERS OF 

 EPIDERMIS. (Biesiadecki ) a, vascular papilla, with capillary loop passing from 

 subjacent vessel, c; h, nerve-papilla, containing tactile corpuscle, t; d, nerve passing 

 up to tactile body ; /,/, section of spirally winding nerve-tibres. 



the sense of touch is exquisite. The papillae, containing tactile 

 bodies, are specially large and numerous on the palm of the 

 hand and the tips of the fingers, and on the corresponding 

 parts of the foot, while on the face and back they are small and 

 irregularly scattered. 



The reticular layer of the corium is a continuation of the 

 papillary layer, there being no real division between them, and 

 is made up of bundles of white fibrous and elastic tissue which 

 gradually blends below with the subcutaneous areolar tissue. It 

 contains networks of blood-vessels, lymphatics, and nerves. 



