THE LIMBS OK THK IlOKSK 



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inflected parts or " bars." Tlie wall, therefore, presents two surfaces and 

 two borders for consideration. The outer surface is convex from side to 

 side, and, in the natural condition, is crossed horizontally by a number 

 of incremental lines that run parallel to each other and parallel to 

 the proximal border of the hoof. The curve of the convexity is wider 

 at the lateral than at the medial " quarter," and the general conformity 

 of the hoof is different in the thoracic and pelvic limbs. 



The angle described by the slope of the wall and the ground plane 

 is obviously different at the "toe" and the "heels." It is greater, 

 i.e. the slope is steeper, on the medial than on the lateral aspect, and 



FlG. 55. — Outline of the Volar and Plantar Aspects of the Hoof of the Thoracic (I.) and 



Pelvic (II.) Limbs. 



A. ="toe." B. = lateral "quarter." C. =medial "quarter." 



also differs in the hoof of the thoracic and pelvic limbs, as is indicated 

 in the following averages given by Lungwitz : — 



It must be borne in mind that these figures do not necessarily 

 apply to any particular specimen. There is a notable variation in the 

 general form and angles of the hoof of apparently perfectly normal feet. 



The length of the wall, i.e. the distance between the two borders, 

 at the " toe," " quarter," and " heel," may be indicated by the ratios 

 3:2:1 for the hoof of the thoracic limb, and 2:li:l for the hoof of 

 the pelvic limb. 



In the neighbourhood of the coronet the outer surface of the hoof 

 is covered by a thin layer of very elastic horn (limbus ungulae) — con- 

 nected with the marginal matrix — polished and glistening when dry, 

 but whitish, swollen, and fibrous when moist. 



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