THE CHIMPANZEES AND ORANGS. 23 
The articular surface on the outer side for the mesocuneiform (fig. 2, m) is divided 
into two in the Gorilla; the upper surface of the bone is broader transversely, shorter 
from bel:ind forward than in Man (fig. 1, m). ‘That of the ectocuneiform (e) shows the 
same difference in a greater degree: it is not produced forward to articulate with the 
outer side of the base of the second metatarsal (27) as in Man. 
The cuboid is also shorter and broader in the Gorilla; the fore and hind articular 
surfaces incline more to each other at the outer part of the bone, where they are 
separated by a narrower non-articular tract, which is more deeply notched (fig. 2, b). 
The surface on the inner side of the bone, for the ectocuneiform, is single and occupies 
the upper half of that side; it is continuous with the surface at the fore part for the 
fourth metatarsal, which is concave; that for the fifth metatarsal is flat, and islarger than 
in Man (fig. 1, 0). 
The metatarsal of the hallux in the Gorilla (fig. 2) shows a corresponding modi- 
fication to that of the entocuneiform (2) in regard to the shape and direction of its 
proximal articular surface, which is concave from side to side, and looks obliquely 
backward and a little outward, affording a favourable position and much freedom of 
motion of the innermost toe, as a flexible prehensile thumb of great power. The whole 
metatarsal is shorter and more slender than in Man; the distal articular surface is 
more convex and bent down. 
The metatarsals of the four other toes are characterized in the Gorilla by their greater 
proportional length and their slight bend downwards. ‘Those of the second, third, and 
fourth toes are also thicker. The fifth metatarsal is more slender in proportion to its 
length ; but the basal process for the attachment of the peronei brevis and tertius is more 
developed and inclined outward. ‘The phalanges are distinguished by their greater 
breadth, as well as length; the proximal and middle phalanges are more bent towards 
the sole ; and on each side of the concave surface there is a ridge for the attachment of 
the aponeurotic sheath of the strong flexor tendons. 
In all the characters by which the bones of the foot depart, in the Gorilla, from the 
Human type, those of the Chimpanzee recede in a greater degree, the foot being in that 
smaller Ape better adapted for grasping and climbing, and less adapted for ‘occasional 
upright posture and motion upon the lower limbs. The lever of the heel is relatively 
shorter and more slender, the hallux has still more slender proportions, and the whole 
foot is narrower in proportion to its length, more curved towards the planta, and more 
inverted, in the Chimpanzee. 
The Skeleton.—Plates XII. & XIII. 
On comparing the skeleton of the Gorilla with that of Man, one is impressed by the 
general massiveness and strength of the bony framework in the great Ape, combined, as 
these characters are, with superior dimensions in the trunk, and with greater length in the 
upper limbs. If the subjects of comparison be, as in Plates XII. and XUII., adult males, 
the contracted cranium, masked and overshadowed by the expansion and production of 
