ANATOMY OF THE HORSE. 3 
Internal surface presenting two places for articulation with the 
magnum. Base , presented forwards. Apex, backwards. 
TRAPEZIUM*. 
Situation —Behind the cuneiform bone. Figure —Flat, broad, 
quadrilateral. Division —Into two surfaces and four borders. 
1st, Internal surface , convex, uneven, in places, elevated and 
roughened for ligamentous attachment. 2d, Internal surface , 
concave and porous.—B orders. Into the superior is fixed the 
tendons of the flexores metacarpi; to the inferior , a ligament; to 
the posterior^ the posterior annular ligament of the knee : the an¬ 
terior possesses two smooth oval surfaces ; one for articulation 
with the cuneiform, the other with the arm-bone. 
PISIFORM BONE. (OS PISIFORME.) 
Not invariably present: in some instances two are found. Si¬ 
tuation —Behind the trapezoid bone. Form —Orbicular or pea¬ 
shaped. Use —Not apparent. 
OF THE FORE LEG. (METACARPUS.) 
Frequently called the camion : sometimes the shank . 
Although three bones enter into the composition of this part, 
viz., the large and the two small metacarpal bones, yet does the 
leg own its form principally, and its support entirely, to the former 
one: — 
LARGE METACARPAL, CANNON, OR SHANK BONE. 
(os METACARPI MAGNUM.) 
Form —Cylindrical; flattened posteriorly. 
Division —Into body and two extremities. 
The Body presents anterior and posterior surfaces. The an¬ 
terior surface is rounded, prominent, and smooth, and extends 
round, laterally, so as to form about two-thirds of the entire su¬ 
perficies of the cylinder.— The posterior surface is flattened, and, 
in places, depressed. About one-third of its length down, it is 
pierced by the medullary foramen, directed inward and downward. 
* Stubbs has made this the Pisiform Bone; whilst the bone called the 
Pisiform is his trapezium. Desirous as I am to observe an adherence to 
the nomenclature of human anatomy, in the present instance, the incon¬ 
gruity appeared to be such as to warrant the hazard of a transposition of 
names. The bone which really is of the form and even magnitude of a pea, 
I have called pisiform ; whilst to Stubbs’ pisiform, a broad, flat, quadrilateral 
bone, I have given the name of Trapezium. Girard, the French standard 
anatomist, calls the small round bone “ pisiforme .” 
