Chap. XVIII] 



THE SKIN 



345 



are constantly being rubbed off the surface of the skin. The pig- 

 ment in the skin of the negro, as well as that of the nipple in white 

 races, is found in the deepest cells of the germinative layer.' 



No blood-vessels pass into the epidermis ; it, however, receives 

 fine nerve-fibrils between the cells of the germinative layer. 





Horny < 



corneum 



stratum lucidum 



stratum 



-ranulos.uin 



O. or M/ 



> 



Germinative 



or 

 Malpighian 



■m. 





^e 



,4^; 





^X'i 



Fig. 170. — Vertical Section throttgh the Skin of the Palmar Side of 

 THE Finger, showing Two Papill.e (One of which contains a Tactile Cor- 

 puscle) AND the Deeper Layer of the Epidermis. (Schafer.) 



Derma. — The derma is a highly sensitive and vascular layer 

 of connective tissue. It is described as consisting of two layers : — 



(1) Superficial, or papillary layer. 



(2) Deeper, or reticular layer. 



(1) The surface of the papillary layer is increased by protru- 

 sions in the form of small conical elevations, called papillse, whence 

 this layer derives its name. They project up into the epidermis, 

 which is moulded over them, and contain for the most part looped 

 blood-vessels, but they also contain the terminations of nerve- 

 fibres in the shape of little bodies called tactile corpuscles. 



