248 PROFESSOR OWEN ON THE EXTERNAL CHARACTERS 



little in comparison with the trunk ; it appears greater through the arrest of development 

 of the lower limbs. Very significant of the closer anthropoid affinities of the Gorilla is 

 the superior length of the arm (humerus) to the fore-arm, as compared with the propor- 

 tions of those parts in the Chimpanzee. The hair of the arm inclines downward, that 

 of the fore-arm upward, as in the Chimpanzee. The thumb extends a little beyond the 

 base of the proximal phalanx of the fore-finger ; it does not reach to the end of the 

 metacarpal bone of that finger in the Chimpanzee or any other Ape : the thumb of the 

 Siamang (Hylobates syndactyla) is still shorter in proportion to the length of the fingers 

 of the same hand. The philosophical zoologist will appreciate the significance of this 

 fact. In Man the thumb extends to, or beyond, the middle of the first phalanx of the 

 fore-finger. 



The fore-arm in the Gorilla passes into the hand with very slight evidence, by con- 

 striction, of the wrist (PI. XLVI. fig. 3), the circumference of which, without the hair, was 

 fourteen inches, that of a strong Man averaging eight inches. The hand (PI. XLVII. 

 figs. 2 & 3) is remarkable for its breadth and thickness, and for the length of the palm, 

 occasioned both by that of the metacarpus and by the greater extent of undivided inte- 

 gument between the digits than in Man ; these only begin to be free opposite the middle 

 of the proximal or first phalanges, and nearer the second phalanx between the third and 

 fourth fingers. The digits are thus short, and appear as if swollen and gouty, chiefly 

 through the callous pads of cuticle on the back of the middle and distal phalanges 

 {ib. fig. 3) : they are also more or less conical in shape after the first joint, by tapering 

 to nails, which, being not larger or longer than those of Man, are relatively to the fingers 

 much smaller. The circumference of the middle digit at the first joint in the Gorilla is 

 5^ inches ; in Man, at the same part, it averages 2f inches. The thick and callous 

 skin on the back of the fingers leaves little outward appearance of the second joint. 

 The habit of the animal to apply those parts to the ground, in occasional progression 

 (PI. XLIV. fig. 1), is manifested by these callosities. The back of the hand (PI. XLVII. 

 fig. 3) is hairy as far as the divisions of the fingers ; the palm {ib. fig. 2) is naked and 

 callous. The thumb, besides its shortness according to the standard of the human 

 hand, is scarcely half so thick as the fore-finger. The nail of the thumb did not extend 

 to the end of that digit ; in the fingers the nail projected a little beyond the end, but 

 with a slightly convex worn margin, resembling the human nails in shape, but rela- 

 tively less. 



In the hind limbs was chiefly noticeable that first appearance in the Quadrumanous 

 series of a muscular development of the gluteus, causing a small buttock to project 

 over each tuber ischii (PI. XLVII. fig. 1). This structure, with the pecuhar expanse, 

 as compared with other Quadrumana, of the iliac bones', leads to an inference that the 



' The intrepid and much-enduring explorer and observer of living nature at the Gaboon, to whom science is 

 indebted for the best and most abundant materials for enlarging our knowledge of the anthropoid Apes, remarks : 

 — "The common walk of the Gorilla is not on his hind legs, but on all-fours." When advancing as a biped to 



