6 PROFESSOR OWEN ON THE OSTEOLOGY OF 



Gorilla, save in size. The medullary arterjr enters the fore part of the shaft, but nearer 

 the middle of the bone in the Gorilla (fig, \,i) than in Man (fig. 8, i) : in both, the course 

 of the canal is towards the elbow-joint. 



The humerus of the male Australian (PI. 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 

 PI. III. But fig. 1 1, taken from the bone of a robust European male, shows the infe- 

 rior development of the condyloid processes {k and o) as compared with the Chimpanzee 

 (fig, 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 PI. III. 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 (Pis. 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 beenfollowedbyinfiammation, 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 ^^ths the length 

 of that bone ; in Man it is shorter by nearly x4-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. Xill. fig. 2). The head (PI. 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 subcyhndrical 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 



