54 HORSESHOEING. 



moisture from the horn. (2) The middle or protective 

 layer (Fig. 35, d) is the thickest, strongest, and most im- 

 portant of the three layers; it forms the principal mass of 

 the wall, and is developed or secreted by the coronary band, 

 which fits into the coronary groove. There are in the coronary 

 groove a great number of small, funnel-shaped openings into 

 which project the horn-producing villi or papillae of the coro- 



FiG. 35. 



The outer wall of the hoof has been removed by cutting vertically through the middle of 

 the toe, down to the upper surface of the sole, then horizontally backward into the quarter, 

 and, finally, upward through the quarter: o, perioplic horn-band; h, coronary groove; it 

 turns inward and forward at c to form the upper border of the bar; d, surface of section of 

 the wall at the toe; d', at the quarter; e, surface of horizontal section of the wall near its 

 lower border; /, keraphyllous layer of the wall; at /' it turns forward and inward to cover 

 the bar; /", horny leaves standing free and passing insensibly into the white horn of the 

 middle layer or true wall; g, horny sole; h, white line; i, small horn-spur in middle of toe; 

 k, part of horny frog which is in intimate union with the upper edge of the bar; I, frog-stay 

 of horny frog; it divides the trough-Uke depression of the upper surface of the frog into m, 

 the two upper channels of the frog. 



nary band. (3) The inner layer or keraphyllous layer (Fig. 



35, /) consists of prominent, parallel horn-leaves lying side by 

 side over the entire inner surface of the middle layer of the 

 wall, and continuing beyond the buttresses to the ends of the 

 bars (Fig. 35, f). This layer of horn-leaves (keraphyllous 

 layer) has in a general way about the same shape and arrange- 

 ment as the layer of fleshy leaves (podophyllous layer) which 

 secretes it; for the horn-leaves fit in with the fleshy leaves in 

 such a way that every fleshy leaf is embraced by two horn- 



