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 healthy 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 periople. 
The Internal Face of the wall, that adapted to the sensi- 
tive laminz, is closely covered over its entire surface with 
79 35 
Fie, 20.—Inrernan Features oF THE Watt, FRoc, AND SoLE 
(Mesian Section or Hoor). 
1, Horny lamin 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 ‘frog- 
stay’); 7, A-shaped ridge on wall and sole (known as the ‘toe-stay’) ; 
8, anterior face of wall ; 9, inferior border of wall. 
white parallel leaves (Keraphylle, or horn leaves, to distin- 
guish them from the Podophylle, or sensitive leaves). These 
keraphylle 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 
