THE HOOF. 21 



point of much practical interest is to be found in the fact, 

 that the fibres on the surface or outside of the wall, are 

 very dense, close, and hard : so dense, indeed, that the 

 wall of an unmutilated hoof looks like whalebone ; but to- 

 ward the inner surface they become softer, more spongy, 

 and easily cut. 



The Homy Sole is contained within the lower margin 

 of the wall, and is a concave plate covering the lower face 

 of the pedal bone. In structure it is fibrous like the wall, 

 the fibres passing in the same direction, and formed in the 

 same manner by the tufts of vessels projected from the 

 membrane which immediately covers the bone. These 

 tufts penetrate the horn fibres to some depth, and, as in 

 the wall, maintain them in a moist, supple condition, such 

 as best fits them for their office. 



The sole is thickest around its outer border, where it 



Fig. 5. — Peaxtar Surface of left Foee Hoof of a Ftve-year-old Hoese that iiad 

 never been shod. — a a, glomes or heels of the frog ; &, median lacuna or " cleft " 

 of the frog ; c c, branches of the frog ; d d, heels, '" angles of inflexion,'' or " but- 

 tresses " of the wall of the hoof; e e, lateral lacunas or spaces between the frog and 

 bars ; ./'/, inflexions of the wall or " bars ; " g, body of the frog ; /*, outside quarter 

 of the hoof; i, inside quarter of the hoof; j, point of the frog; Jc, sole; 1 1, commis- 

 sure, " white line," or line of junction between sole and wall ; m n, mammilla ; o, 

 toe. 



joins the wall; thinnest in the centre, where it is most 

 concave. A notable peculiarity in this part of the hoof, 

 and one which distinguishes it from the wall, is its ten- 



