54 OSTEOLOGY OF THE IIOIISE. 



uniting with the cuneiform. 2d, Ltfeiiur surface, aiticiihitoiy, 

 resting upon the outer splint, and also upon the cannon bone. 

 3d, Eitenial surface convex and rough, and ligamentous. 4th, 

 Interiial surface presenting two places for articulation with the 

 magnum. Base, presented forwards. Apex, backwards. 



TRAPEZrUM*. 



Situation — Behind the cuneiform bone. Figure — Flat, broad, 

 quadrilateral. Division — Into two surfaces and four borders. 

 Jst, External surface, convex, uneven; in places, elevated and 

 roughened for ligamentous attachment. 2d, Internal surface, 

 concave and porous. ^-Borders. Into i\\esuperior 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, line — Not apparent. 



OF THE FORE LEG. (METACARPUS ) 



Frequently called the cannon : 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 owe 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- 



* Stubbs has made this the Pisiform Bone; whilst the bone here 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, ipiadrilateral 

 bone, I have given the name of Trapezium. Girard, the French standard 

 anatomist, calls the small round bone " pisiforme." 



