CHAPTER Vl. 



THE PROTECTIVE STRUCTURES OF THE FOOT. 



The portions of the limb which have, up to the present, been 

 studied, are, like all other portions of the body, covered and 

 protected from injury by the skin. The covering of the foot, 

 however, differs from that of all other parts of the body. 

 The Skin.—ThQ skin 



or 



common intecjument 



is divided into a super- 



A. 



ticial epidermis and a 

 deeper corium or true 

 skin. The epidermis or 

 scarf skin is composed 

 of a multitude of cells 

 united tos^ether so as to 

 form a layer that covers 

 the entire body. From 

 it are derived certain 

 structures, such as hairs, 

 horns, and hoofs, which 

 have important func- 

 tions to perform, and 

 so to render parts of 

 the body more lit for 

 the purposes to which 

 they are put. In animals 

 that have coloured skins, 

 or skins provided with 

 a thick hairy cover- 

 ing, the epidermis is found to be divided into two por- 

 tions, — one the rete mucosum or stratum malpighii ; the 

 other, and one that is constantly shed as scurf, the 



61 



Fig. 39. — Vertical section through the human nail and 

 nail-bed. a, stratum malpighii of nail-bed ; b, stratum 

 granulosiim of nail -bed ; c, the deep layers of the nail 

 substance ; d, the superficial layers of same. (From 

 Klein's Histology.) 



