380 



THE ANATOMY OF THE HORSE 



in flout. Deact'iidiiig from the body is the thin wctlge of boue uliicli is 

 united indissolubly with the shaft of the radius at the point marked 5, 

 and may be traced down to the car[)al joint. 



The articular surface comprises part of the elbow joint, and has below it 

 some roughened inequalities for the attachment of ligaments. 



The olecranon ^jroccss, or elbow, is of considerable size and strength, form- 

 ing a strong lever for the action of the triceps muscle, which is inserted in 

 its point. Its anterior edge has a sharp point, which deepens the articular 

 lavity, and checks the motion of the joint from being carried too far. 



THE CARPUS (KNEE) AND METACARPUS 

 (CANNON) 



The knee of the horse corresponds with the wrist of man, and though the 

 name so well known to horsemen will probably alwa3^s be maintained, yet 

 scientifically each of the bones i-eceives the corre- 

 sponding names, and the whole group is called the 

 carpus. 



The anterior surface of the carpus is convex ; the 

 posterior, concave and irregular, and marked by bony 

 prominences. 



It consists of eight bones, disposed in two rows, 

 one above the other, as follows : — 



The first, or top row, beginning to enumerate 

 from Avithin outwards, consists of the scaphoid, lunar, 

 cuneiforme, and pisiforme bones. 



The second, or lower row, consists of the essa tra- 

 pezoid, magnum, and unciforme, and sometimes of a 

 small fioating bone situated behind the trapezoid. 



The superior row may be described as follows : — 



Os ScAPHOiDES {(TKCKpri, a cradle), the largest of 

 this row, articulates superiorly Avith the inferior and 

 inner extremity of the radius, internally by means of 

 two distinct facettes with the os lunare, and inferi- 

 orly with the os trapezoidcs and os magnum. 



Os LuxAEE (luna, the moon) articulates superi- 

 orly with the radius, internally as before mentioned 

 with the OS scaphoides, and externally through the 

 medium of two facettes with the os cuneiforme. 



Os Cuneiforme (cuneus, a tccJge) articulates supe- 

 riorly with fhe iirferior and outer extremity of the 

 radius, inferiorly with the os unciforme, and pos- 

 teriorly with the OS pisiforme. 



Os Pisiforme (pisum, a j^ea) is situated at the 



postero-external side of the top row, and presents 



for description two surfaces and four borders. The 



external surface is unevenly convex, and elevated 



for ligamentous attachment. The internal surface is concave and porous, 



and also roughened for ligamentous attachment. The anterior boi-der 



?io. 27. — FoiiE View of 

 THE Carpal Bones, cow- 



MONLY CALLED TUE KnEE. 



'2. Lower extroinity < f 

 radius. 



3. Ulna, lower exUtiiiiU 



of. 



4. Os pisifonue. 



5. — cuneiforme. 

 t>. — lunare. 



7. — scaphoides. 



8. — unoifonne. 



9. — magnum. 



10. Larjte metaoaiijal bone. 



11. Small metacarpal bone. 



