10 PROFESSOR OWEN ON THE OSTEOLOGY OF 
of the radial tuberosity of the bone (ib. 6). The articular surface for the trapezoides 
(ib. s) curves almost into contact with the radial surface at the back part of the bone ; 
that for the trapezium (d) is less near the upper surface and radial (outer) end. The 
two surfaces are continuous, as in Man, but of relatively greater extent transversely. 
On the ulnar and inner side of the scaphoid (fig. 6) the surface (J) for the lunare is 
relatively larger; that (a) for the os magnum is relatively less and shallower than 
in Man (fig. 8, a). The production of the radial tubercle (figs. 5 & 6, b) is, however, 
the main difference, and relates to the greater lever-power of the flexor carpi radialis 
therein inserted. In the os lunare the ulnar side of the bone (Pl. II. fig. 9) shows, 
in the Gorilla, a more equal division between the articular part (a) for the cunei- 
forme and the non-articular part, than in Man (ib. fig. 10). The concave crescentic 
surfaces for the os magnum (b) and scaphoides are similar to those in Man; but the 
latter is more excavated, and they are divided by a sharper ridge. The os cuneiforme 
in the Gorilla (fig. 13) is distinguished from that of Man (fig. 14) chiefly by its greater 
transverse extent, with similar proportions of the articular surfaces for the unciforme 
and pisiforme (figs. 13 & 14, a). The tubercle at the ulnar end, for the attachment of 
the internal lateral ligament of the wrist, is more developed and better defined in Man 
than in the Gorilla. The pisiforme of the Gorilla (Pl. II. fig. 11) is much longer in 
proportion to its breadth than in Man; whilst the articular surface for the cuneiforme 
(a) is but little larger: its superior length gives stronger leverage to the great ulnar 
flexor of the wrist. The trapezium of the Gorilla differs most from its homologue in 
Man by the production of its outer unarticular surface into two diverging tuberous 
processes: the articular surface, moreover, for the metacarpal of the thumb is rela- 
tively much smaller than in Man, and it is divided by a wider non-articular tract from 
the surface for the base of the index digit: this is continuous, as in Man, with the 
surfaces for the trapezoides and scaphoides. The trapezoides (Pl. X. fig. 1, <) is a 
larger and especially a broader bone than in Man (wb. fig. 2, 2); the surface for articu- 
lation with the base of the index metacarpal is longer from before backward, 
and more nearly approaches that for the scaphoides. The figures of the trapezoides, 
Pl. Il. figs. 15 & 16, show the articular surface for the scaphoid in Man and the 
Gorilla, the bone of the latter being from a younger male specimen than in the hand 
figured in Pl. X. The rough dorsal surface of the os magnum (PI. X. fig. 1, m) is some- 
what broader but not more extensive than in the human os magnum (id. fig. 2, m). 
The dimension in which this wrist-bone in the Gorilla most surpasses that in Man 
is from without inwards or towards the palm: the difference is illustrated in the views 
of the articular surface for the base of the middle metacarpal in figures 17 (Gorilla) and 
19 (Man) of PI. II.: the risings and hollows of this surface are also more marked in 
the Gorilla, giving a firmer attachment of the metacarpal bone to the wrist. On the 
radial side of the os magnum, that border of the articular surface for the metacarpal 
(a and 8, fig. 20) runs along the upper part in Man: it is interrupted by a deep depres- 
