HORSESHOEING. 41 



an extension of the derm or middle layer of the hair-skin, it 

 ■ differs from the latter in structure and relations. 



In order to study the pododerm we should not wrench the 

 hoof off with violence, but should allow the foot to partially de- 

 compose by leaving it for six to eight days in ordinary room tem- 

 perature ; it can then be removed without injuring the pododerm. 

 After the hoof has been removed the entire pododerm presents 

 a more or less dark-red color (flesh-color), which is due to the 

 great number of blood-vessels that it contains. For this reason 

 different parts of the pododerm have received the prefix "fleshy," 

 as for example, fleshy wall, fleshy sole, fleshy ffog, etc. The 

 pododerm is what the uninformed horseshoer calls the " quick." 

 I will here remark that the three layers of the external or hair- 

 skin are represented in the foot ; however, the epidermis is in 

 an entirely different form, — namely, the horny box or hoof. The 

 internal layer or subcutaneous tissue of the hair-skin is absent 

 in those parts of the foot where the pododerm covers the os pedis. 

 There remains, therefore, only the middle layer, derm, or podo- 

 derm, which secretes the hoof, and which is the prolongation and 

 representative of the middle layer of the hair-skin. The podo- 

 derm is distinguished from the derm of the hair-skin chiefly by 

 the absence of hairs, oil- and sweat-glands, and the presence on 

 its outer surface of fleshy, sensitive laminae and small thread- 

 like projections called villi. 



The pododerm consists of five different parts : the perioplic 

 band, the coronary hand, the sensitive laminae (podophyllous tissue), 

 the velvety tissue of the sole, and the velvety tissue of the fleshy frog. 



1. The perioplic band (Fig. 23, b) is a narrow ridge, about one- 

 fifth to one-fourth of an inch wide, lying between the hair-skin 

 and the coronary band. Somewhat broader at the toe than on 

 the sides, it broadens out near the bulbs of the heels, over which 

 it passes to end in the velvety tissue of the fleshy frog. It is 

 separated from the coronary band by a narrow depression called 

 the coronary furrow (Moeller). The surface of the perioplic band 

 glistens faintly, and is thickly studded with numerous thread- 



