52 OSTEOLOGY OF THE HORSE. 



surface between the humeral condyles behind. — The projeclion, 

 named tJie olecranon, the part corresponding to the elbow in man, 

 is one of considerable magnitude, standing out in a direction u|)- 

 wards and backwards from the upper extremity of the radius; it is 

 prominent and uneven on its outer side, excavated and smooth on 

 its inner, and terminates in a broad, rough protuberance, into 

 which is implanted the triceps extensor brachii. In addition to 

 two sides, it possesses two borders, both sharp, and disposed in 

 curvatures looking inwardly: the anterior terminates in a project- 

 ing point, which forms the superior boundary of the articular sur- 

 face ; the posterior extends down, and becomes continuous with 

 that of the body. 



Connexion. — With the humerus, above; with the scaphoid, 

 lunar, and cuneiform bones, below. 



Development. — In young life the ulnar portion forms a distinct 

 bone from the radial, the two pieces corresponding to the ulnar 

 and radius in man or the dog: indeed, the former in the colt ex- 

 tends nearly to the knee; but as life advances, the two portions 

 become so completely amalgamated and cemented together, in- 

 feriorly, that no longer can any trace be found of their original 

 separateness. 



OF THE KNEE. (CARPUS.) 



The knee of the horse corresponds to the wrist of man, and for 

 this reason is technically considered as the carpus. It is com- 

 posed of seven small bones: in some instances an eighth has been 

 found. Six of these bones are ranged in rows, forming two tiers, 

 consisting each of three pieces : the seventh is placed completely 

 behind the others. 



The First, or Superior Row, is formed by the scaphoid, lunar, 

 and cuneiform bones. 



The Second, or Inferior Row, by the trapezoid, great, and un- 

 ciform bones. 



SCyVPHOIl) DONE. (oS SCAPHOIDES.) 



Form — Semi-ovoid : convex and curvated on one side; slightly 

 but unevenly concave on the opposite. — Divided into four sur- 

 faces : — 1st, Superior surface, sigmoid and smooth, articulating 

 with the arm-bone. 2d, Inferior surface, semi-ovoid and smooth, 

 resting upon the trapezoides and magnum. 3d, Interna/ surface, 

 convex, and roughened l)y the attachment of the lateral ligaments. 

 4th, Interna/ surface, uniting in two distinct places with the lunar 

 hone. 



