anatomy of the horse. 429 
The Ulnar Portion consists of body, projection, and articu¬ 
latory surface. 
The body is the tapering triangular part which is firmly united 
above, but more intimately below, with the radial portion; be¬ 
tween the two is an interval, admitting of the passage of a circulus 
of blood-vessels.— The surface composing part of the humero- 
brachial articulation, in form a semilunar concavity, is only in part 
articulatory, the lower half presenting roughened inequalities for 
ligamentous attachment: it is adapted to the smooth trochleal 
surface between the humeral condyles behind.— The projection^ 
named olecranon^ the part corresponding to the elbow in man, 
is one of considerable .magnitude, standing out in a direction up¬ 
wards and backwards from the up])er extremity of the radius, 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¬ 
teriorly, that no longer can any trace be found of their original 
.separateness. . ... — . ' ... 
^ v w - . (To be continued.) _ ^ . 
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