The =carpus= consists of six bones, four in the upper row, and two in the lower. The upper row is oblique in conformity with the carpal articular surface of the radius. The radial and intermediate resemble in general those of the horse, but are less regular in shape, and their long axes are directed obliquely backward and inward. The radial is narrower than in the horse and curves upward behind. The intermediate is constricted in its middle, and wider behind than in front. The ulnar is large and very irregular. Its proximal surface is extensive and sinuous and articulates with both radius and ulna. Behind is a large oval facet for articulation with the accessory carpal. The accessory is short, thick, and rounded; it articulates with the ulnar carpal only. The first carpal is absent. The second and third carpals are fused to form a large quadrilateral bone. The fourth carpal is a smaller quadrilateral bone. The =metacarpus= consists of a large metacarpal and an external small metacarpal bone. The large metacarpal bone (Mc. 3 + 4) results from the fusion of the third and fourth bones of the fœtus, and bears evidences of its double origin even in the adult state. The shaft is shorter than in the horse, and is relatively wider and flatter. The anterior surface is rounded, and is marked by a vertical vascular groove connecting two canals which traverse the ends of the shaft from before backward. The posterior surface is flat and presents a similar but much fainter groove. The borders are rough in the upper third. The proximal end bears two slightly concave facets for articulation with the bones of the lower row of the carpus; the inner area is the larger, and they are separated by a ridge in front and a notch behind. The outer angle has a facet behind for the small metacarpal bone. The inner part of the extremity has anterior and posterior tuberosities. The distal end is divided into two parts by a sagittal notch. Each division bears an articular surface similar to that in the horse, but much smaller. The =medullary canal= is divided into two parts by a =vertical septum= which is usually incomplete in the adult. The =small metacarpal= bone (Mc. 5) is a rounded rod about an inch and a half (ca. 3.5 to 4 cm.) in length, which lies against the upper part of the outer border of the large bone. Its upper end articulates with the latter, but not with the carpus. The lower end is pointed. Four cartilaginous metacarpals are present in the early fœtal state, viz., the second, third, fourth, and fifth. The second commonly either disappears or unites with the third; sometimes it develops as a small rod of bone. The third and fourth gradually unite, but can be cut apart at birth. Each has three centers of ossification; the proximal epiphysis fuses with the shaft before birth, the distal at two to two and one-half years.