10 PROFESSOR OWEN ON THE OSTEOLOGY OF 



of the radial tuberosity of the bone (ib. 6). The articular surface for the trapezoides 

 (ib. z) 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 (/) 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, 6) 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 (PI. 11. 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 {ih. 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 (PI. 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 fi'om 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 (PI. X. fig. 1, s) is a 

 larger and especially a broader bone than in Man (ib. fig. 2, z) ; 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, 

 PI. II. 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 PI. 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 (ib. 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 6, fig. 20) runs along the upper part in Man : it is interrupted by a deep depres- 



