316 



THE EXTERIOR OF THE HORSE. 



laminae intimately united to the horn which descends from the coronary band. 



This adherence of the two horny productions is so strong that it resists the most 



prolonged maceration. Behind, the lam- 

 inae are reflected into each of the lateral 

 lacunae of the plantar cushion, and are 

 in relation with that part of the parietes 

 of the hoof which is called the bars. 



c. The villous or velvety tissue 

 (Fig. 107, B : d), whose aspect approaches 

 that of a bushy sod, in consequence of 

 the innumerable villosities over its sur- 

 face, covers the whole of the plantar sur 

 face of the third phalanx and the plantar 

 cushion or: fleshy frog. Like those of the- 

 cutidure, these papillae are received into 

 the numerous foramina of the subjacent 

 horn which is produced by the most 

 superficial layer of the velvety tissue. 



2. The Hoof. 



The hoof, as we know, is the exter- 

 nal horny envelope of the foot, or, more 

 properly speaking, the nail of the horse. 

 Its form is that of a cone with its base 

 downward and the summit truncated 

 obliquely from above to below and from, 

 before to behind (Fig. 108). Its conical 

 disposition, however, being always very- 

 slight, is only very apparent when it ia 

 examined from in front or behind. 

 Viewed in profile, it has more the form 

 of a cylinder, as has been remarked by 

 Bracy-Clark ^ (Fig. 109). 



Concave below, cleft behind, and 



bordered superiorly by the skin of the 



coronet, the hoof is composed of three 



distinct pieces intimately united to one 



another. These pieces can be separated 



the one from the other by prolonged 



maceration or boiling; they are designated under the names wall, sole, and 



frog. We must enter into a special study of each in order to understand the 



mechanism well. 



a. The "Wall. — The wall or paries forms, as its name indicates, the circum- 

 ference of the hoof, and includes all that portion of the horny case which is visi- 

 ble when the foot rests upon the soil. It represents a large crescent of horn» 

 curved on itself (Fig. 110), placed against the anterior face of the foot on which 



Fig. 108.— Foot viewed in front. 



1 Bracy-Clark, Recherches sur la construction du sabot du cheval. 



