REGIONAL ANATOMY 



39 



marked by a series of rings which run horizontally from 

 heel to heel. These are due to varying influences of food, 

 climate, and slight or severe disease. This will be noted 

 again in a later page. In a young and healty horse the 

 whole of the external face of the wall is smooth and 

 shining. This appearance is due to a thin layer of horn, 

 secreted independently of the wall proper, termed the peri- 

 ople. 



The Internal Face of the wall, that adapted to the sensi- 

 tive laminae, is closelv covered over its entire surface with 



Fig. 20.— Internal Features of the Wall. Frog, and Sole 

 (Mesian Section of Hoof), 



i, Horny laminae covering internal face of wall; 2, superior border of 

 wall; 3, junction of wall with horny sole ; 4, the cutigeral groove ; 

 5, the horny sole ; 6, the horny frog ( that portion of it known as 

 the 'frogstay') ; 7, A-*haped ridge on wall and sole (known as 

 the 'toe-stay') ; 8, anterior face of wall ; 9, inferior border of wall. 



white parallel leaves ( Keraphyllor, or horn leaves, to distin- 

 guish them from the Podopli\Ua\ or sensitive leaves ). These 

 keraphylke dovetail intimately with the sensitive laminae, 

 covering the os pedis. Running along the superior portion 

 of the inner face is the Cutigeral Groove. This cavity has 

 been mentioned before as accommodating the coronary 

 cushion, whose shape and general contour it closely follows, 

 being widest and deepest in front, and gradually decreasing 

 as it proceeds backwards. It is hollowed out at the 

 expense of the wall, and shows on its surface numberless 



