48 STRUCTURE OF THE SKIN. 



same kind is found in the matrix or receptacle of the growing 

 roots of nails, hoofs, horns, &c. which are only modified forms 

 of epidermis. Imbedded in the substance of the cutis wo 

 find, in most situations, the perspiratory glands (fig. 7, e e.), by 

 which the watery fluid that is continually being exhaled from 

 the skin, is separated from the blood ( 371) ; these send forth 

 their secretion by canals (g 7i), which traverse the epidermis 

 in a corkscrew-like manner, and then open upon its surface 

 by oblique valvular orifices. In the Cutis, also, are lodged 

 the hair-follicles ( 38), which are really pits or depressions 

 of its surface, with a vascular papilla at the bottom of each, 

 supplying nutriment for the abundant development of the 

 cells in which the hair originates, as will be presently 

 described. Wherever the hair-fol- 

 licles occur, there do we also find 

 sebaceous follicles (fig. 8, a a) ; these 

 are peculiar glandule, secreting fatty 

 matter, which is poured into the hair- 

 canal, so as to come through it to the 

 surface of the epidermis ; and the use 

 of this secretion, which is particularly 

 abundant in the dark skins of the 

 natives of warm climates, is to pre- 

 vent the cuticle and the hair from 

 being too much dried up by exposure 

 to air. The surface of the Cutis is 

 covered by a layer of basement-mem- 

 brane ( 31), which is not traversed 

 either by blood-vessels, nerves, or 

 absorbents ; so that none of these 

 pass into the epidermis which lies on 

 its outer side. 



38. The Epidermis, otherwise 

 termed the cuticle, or " scarf-skin," is 

 OF THE HTTMAN composed of numerous layers of nu- 



SCALP; a a, sebaceous glands; cleated Cells : of which WC find those 

 6, a hair, with its follicle c. ^ immediate contact with the bage , 



ment-membrane to be nearly spherical ; those a little removed 

 from it to be rendered polygonal by the mutual pressure of 

 their sides ; those nearer the outer surface to be flattened, 

 and this in an increased degree, as we pass from within 



