SKIN. 



[ 579 ] 



SKIN. 



ing a tolerably dense and firm tissue, with 

 small areolae, and sometimes presenting 

 laminae. The elastic tissue is less abundant 



than the areolar, and consists of networks of 

 finer or coarser fibres. 



The outer surface of the cutis gives off a 



Fig. 646. 



Fig. 647. 



- ~c 



Fig. 646. Perpendicular section of the skin of the under surface of the end of the thumb, through three furrows, 

 a, cuticle ; b, rete mucosum ; c, cutis vera ; d, upper part of subcutaneous tissue ; e, papillae of the cutis ; /, fatty 

 tissue ; g, sudoriparous glands ; A, sudoriparous ducts ; i, orifice of the latter. Magnified 20 diameters. 



Fig. 647. Papillae from the skin of the under part of the end of the finger, a, axial body ; b, nerve ; c, its terminal 

 loop ; d, d, loops of capillary blood-vessels. Magnified 250 diameters. 



number of conical processes or papillae (fig. 



646 e), which are frequently bifid, lobed, or 

 arise several from a common base. In many 

 parts of the skin they are arranged in more 

 or less regular rows. The areolar tissue of 

 the papillae is often homogeneous, especially 

 in the median portion, where in certain pa- 

 pillae it forms an oval transparent body (fig. 



647 d), surrounded by a layer of imperfectly 

 developed elastic tissue, consisting of spindle- 

 shaped cells and fibres taking a horizontal or 

 circular direction, and giving the oval bodies 

 a transversely striated or laminated appear- 

 ance. These oval or axial bodies, as they 

 are called, have been supposed to be con- 

 nected with sensation, an assumption which 

 Kolliker has rendered at least improbable. 

 The papillae are traversed by the terminal 



loops of the cutaneous capillaries (fig. 647 d) 

 and nerves (fig. 647 c). 



The cutis is continuous beneath with the 

 subcutaneous cellular or properly areolar 

 tissue (fig. 646 d}, which is of a much more 

 lax texture than the cutis, presenting large 

 areolae filled with fatty tissue (fig. 646 f). 



The cutis is everywhere covered externally 

 by the epidermis, which is a semitransparent 

 coat, containing neither vessels nor nerves, 

 moulded as it were upon its surface (fig. 648) 

 and filling up the intervals between its 

 papillae (fig. 649). The variously arranged 

 lines seen upon its outer surface are depres- 

 sions corresponding to those existing upon 

 the cutis between its rows or groups of 

 papillae. 



The epidermis consists entirely of nucleate d 

 2p2 



