THE HOESE. 



4t 



ginis. — A. The body presents two surfaces, 

 anterior and posterior ; the anterior is con- 

 vex, the posterior flattened and uneven ; it 

 lessens in bulk in an inferior direction. 



Q. HoviT is the superior extremity of the 

 pastern bone recognized from the inferior ? 



— A. The superior is the largest, and pre- 

 sents two shallow articular cavities; between 

 them is a groove, which receives the central 

 eminence of the inferior extremity of the 

 cannon bone. The inferior extremity is 

 much smaller than the superior; it is bi- 

 convex, and consists of two articular con- 

 vexities, separated by a transverse shallow 

 depression. 



SESSAMOID BONES (oSSA SESSAMOID^). 



Q. Where are the two sessamoids situ- 

 ated ? — A. At the posterior part of the 

 articulation formed by the cannon and 

 pastern bones. 



Q. What is the form of these bones ? — 

 A. Trapezoid: three sides present triangular 

 faces, whose apices unite in one point, which 

 is directed upwards ; the bases of the same 

 form a fourth side, which is turned down- 

 wards ; and are therefore divided into three 

 sides, base, and apex. 



Q. Give a general description of the 

 faces or surfaces of these bones. — A. They 

 are known as anterior, posterior, and lateral 

 faces ; the anterior are excavated, smooth, 

 and articulatory, and along their inward 

 borders — which are opposed to each other 



— are levelled off, so that the two form a 

 groove for the reception of the central 

 eminence of the inferior portion of the can- 

 non. The posterior surfaces are convex and 

 rough ; the lateral surfaces are grooved and 

 roughened; the bases are narrow and uneven. 



Q. What appears to be the qbject in ex- 

 cavating the anterior surfaces of these 

 bones ? — A. To extend the articulatory 

 surface of the pastern joint, and admit of 

 extensive anterior and posterior motion. 



Q. For what purposes are the posterior 

 surfaces roughened ? — A. For the insertion 

 of the suspensory ligaments. 



Q. What occupies the cavity which 

 occurs in consequence of miiting the inter- 



nal surfaces of these bones ? — A. The flexor 

 tendons. 



Q. What ligaments are inserted into the 

 bases of these bones ? — A. The long, 

 short, and crucial ligaments. 



CORONET BONE (oS CORON^). 



The OS cor once is situated beneath, or 

 rather inferiorly, to the pastern, and may 

 therefore be termed the inferior pastern; 

 it occupies a location between the superior 

 pastern and coffin bone. 



Q. Describe the os coronae, or inferior 

 pastern. — A. It presents a square body ; its 

 breadth, however, somewhat exceeds its 

 longitudinal measurement. It has four sur- 

 faces, viz., superior, inferior, anterior, and 

 posterior ; the superior surface is bi-concave, 

 corresponding to the projections of the 

 superior pastern ; the inferior surface is bi- 

 convex, consisting of two condyloid prom- 

 inences, separated by a slight transverse 

 depression, corresponding to the articulatory 

 surface of the coffin-bone ; the anterior sur- 

 face is convex, yet rough and irregular ; the 

 posterior surface is quite smooth, yet exca- 

 vated. 



Q. What are the connections of the oa 

 coronEB ? — A. It connects with the pastern, 

 coffin, and navicular bones. 



BONES OF THE FOOT. 



THE COFFIN BONE (oS PEDIs). 



The coffin bone is considered as the base 

 of the osseous structure of the fore extremity. 



Q. What is the form of the coffin bone ? 

 — A. It presents a semilunar outline; an- 

 teriorly and superiorly it is convex ; pos- 

 teriorly and inferiorly it is concave ; it is 

 divided into wall, sole, tendinous surface, 

 articulatory surface, and wings. 



Q. Describe the wall. — A. It is a 

 miniature of the form of the hoof; it exMbits 

 a porous and furrowed surface, and has in- 

 numel-able perforations, varying in size and 

 form ; its superior part is surmounted by 

 the coronal process; the inferior edge of the 

 wall is somewhat oval, and is notched and 

 serrated. 



