6 PROFESSOR OWEN ON THE OSTEOLOGY OF 
Gorilla, save in size. The medullary artery enters the fore part of the shaft, but nearer 
the middle of the bone in the Gorilla (fig, 1,7) than in Man (fig. 8,7): in both, the course 
of the canal is towards the elbow-joint. 
The humerus of the male Australian (Pl. III. figs. 8, 9, & 10) is more slender 
than that of the average male European, the difference of size and strength being 
illustrated by the lower end of the bone, fig. 11, as compared with that of fig. 8, in 
Pl. III. But fig. 11, taken from the bone of a robust European male, shows the infe- 
rior development of the condyloid processes (k and 0) as compared with the Chimpanzee 
(tig. 5); and the same difference in relation to muscular attachments is exemplified by 
the tuberosities (d and e) at the upper end of the bone (fig. 8). The intercondyloid 
perforation is occasionally seen in the Human humerus ; and, apart from the differences 
relating to size and strength of muscle, the most significant mark of nearer resemblance 
to Man which I have been able to observe in the subjects of comparison here illustrated, is 
the minor degree of production of the ulnar or inner border of the trochlea (q) in the 
Gorilla, as compared with that in the Chimpanzee. ; 
The humerus of the Gorilla, fig. 1, is that of the full-grown but young male the 
skeleton of which is in the Museum of the College of Surgeons, and was the only one 
in England at the time (1851) when the subjects of Pl. II]. were drawn on stone; the 
proximal epiphysis had not coalesced with the shaft of the bone. The humerus of the 
old male in the skeleton of the Gorilla (Pls. XII. & XIII.) in the British Museum, shows 
a striking development of all the processes and ridges for muscular attachment above 
described. The left humerus in this individual had been severely fractured, and the 
injury had been followed by inflammation, enlargement, exostosis, and partial exfoliation 
of the distal portion of the bone, without any union. 
Radius.—Plate IV. 
The radius of the Gorilla (figs. 1 & 2) is shorter than the humerus by 7';ths the length 
of that bone; in Man it is shorter by nearly ;4;ths of the humerus; in the Gorilla 
it is relatively stronger and more bent from the ulna, leaving a wider space between 
the shafts of the two bones (PI. XillI. fig. 2). The head (Pl. IV. fig. 2) is circular, 
depressed in the centre, with a convex thick circumference, which is deepest and 
smoothest next the ulna, for the marginal articulation with the ‘lesser sigmoid 
cavity’ of that bone. The smooth subcylindrical neck (a), becoming contracted as it 
leaves the head, gradually expands to the place of development of the tuberosity (d), 
This shows a well-marked oblong rough prominence for the insertion of the tendon of 
the biceps, behind or ‘ulnad’ of the smoother prominence supporting the bursa inter- 
posed between it and the tendon. Below the tuberosity the shaft assumes a pyriform 
transverse section through the development of the interosseous ridge, which extends 
to near the ‘sigmoid cavity.’ About one-third down the shaft a second but lower 
ridge begins, which extends to the process dividing the groove for the extensor digitorum 
