TEE INTEaVMENTAEY APPENDAGES. 



807 



tious is confounded witli the frog and sole ; the lower appears hetween'these 

 two parts, and is effaced at a certain distance from the point of the frog. 



Sole. — The sole is a thick horny plate comprised between the inner bor- 

 der of the wall and its reflected prolongations ; thus occupying the inferior 

 face of the hoof. It offers two faces and two borders or circumferences. 



The inferior, or external face, forms a more or less concave surface, 

 according to circumstances. The superior, or internal face, corresponds to 

 the peripheral portion of the velvety tissue ; it shows a multitude of little 

 v.pertures analogous to those of the cutigeral cavity, into which are inserted 

 the papillae of the keratogenous membrane. 



The external border, or large circumference, is united, throughout its 

 extent, to the inner contour of the lower border 

 of the wall, by means of its denticulse, which 

 are reciprocally dovetailed into those on the 

 inner face of the wall near its inferior border. 

 The internal border, or small circumference, is a 

 deep, V-shaped notch, widest behind, which cor- 

 responds to the bars, and at the bottom of which 

 the point of the frog is fixed. 



Frog. — This is a mass of horn, pyramidal in 

 shape, and lodged between the two re-entering 

 portions of the wall. It offers four planes (or 

 sides), a base, and a summit (or point). 



The inferior and the two lateral planes con- 

 stitute the external surface of the organ. The 

 first is hollowed by a longitudinal excavation, 

 which is shallow in well-formed hoofs, and is 



named the median lacuna of the frog, separating plantar ok ground surface 

 the two salient portions, or branches, which di- — ■ •—""■ "'-"- ''""■'' 

 ver^e posteriorly and join the heels. The other 

 two°planes are directed obliquely downwards and 

 inwards; they adhere closely, at their upper third, 

 to the external side of the bars, and anteriorly 

 to the inner border of the sole. " This union 

 is so close that no line of demarcation is appa- 

 rent between these parts, and their separation 

 can only be obtained by prolonged maceration. 

 The non-adherent, or free portion, forms the inner 

 side of the angular cavities known as the lateral 

 lacunm, or commissures of the frog, whose external 

 side is constituted by the inferior face of the bars. —Bouley. 



TlTluperiorplIne, forming the internal face of the frog is cnbbled 

 with holes like that of the sole, and is exactly mouded on the pyramidal 

 tody of the plantar cushion. It also offers a triangular excavation, divided 

 posteriorly into two latter channels by a prominence directed fi^m before 

 backwards, to which Bracy Clark gave the name f frog- fay but which 

 M Xley prefers to designate the spine or rtdge {afe) of tUfrog 



The to or posterior extremity of the frog, constituted by the extremities 

 of its branches, forms two romided, flexible, and elastic eminences separated 

 from e^h other by the median lacuna; they cover the angles of inflexion of 

 the wall and are continuous at this point with the perioplic band. Bracy 

 Olark named them the glomes of the frog. 



With regard to the summit, or anterior extremity of the organ, it is a 



OF A hoof; right foot. 

 The interval from a to a repre- 

 sents the toe ; From a to 6, b, 

 outside and inside quarters; 



c, 0, Commencement of bars ; 



d, d, Inflexions of wall at the 

 heels, or " buttresses ;" e, La- 

 teral lacuna ; /, /, /, Sole ; g, 

 White line; g', g'. Ditto be- 

 tween the sole and bar ; h, 

 Body of frog; i, Branch of 

 frog ; k, L Glomes, or heels of 

 frog ; I, Median lacuna. 



