766 



THE SENSE ORGANS AND SKIN OF THE HORSE 



The superior or inner surface is convex, and slopes with a varying degree of 

 obliquity downward to the convex border. It presents numerous small funnel-like 

 openings which contain the papilla of the sole matrix in the natural state 



Wall 



Lamince of wall 



Laminar matrix 



Third phalanx 



Plantar cushio/i 



Bar 



Frog 



Space between 

 bar and frog 



Angle of heel 



Periople of heel 



Fig. 574. — Cross-section of Foot of Horse, Cut 1'ar.\llel with the Coronary Border, 



The inferior or ground surface is the converse of the preceding. It is normally 

 arched — and more strongly in the hind than in the fore foot — but the curvature is 

 subject to wide variation; in heavy draft horses the sole is commonly less curved 



Periople 



Coronari/ 



groove 



Laminai 



riople of heel 



Lateral ridge 



1171 ; T Sole (frog cmd bar) 



White line '^'"e 



Vu;. 575. — Half of ?Ioof of Horse Internal Surface 



than in the lighter lireeds and may even be flat. The surface is usually rough, 

 since the horn exfoliates here in irregular flakes. 



The convex border is joined to the wall by relatively soft horn, previously 



