799 



verse extent, and due to the greater development of the rough convex protuberance at the 

 inner end of the bone : the astragalar concavity is longer transversely than in Alan, less oval, 

 and more elliptic in figure, and with the border more sharply defined ; the surface for the 

 cuneiform bones is nearly like that in Man in size and shape, but it is continuous at the inner 

 end of the bone with the astragalar surface. In the Chimpanzee the astragalar surface of the 

 naviculare more resembles the shape of that in Man. The entocuneiform has an equal verti- 

 cal, but a minor longitudinal, extent than in Man, and chiefly differs in the convexity of the 

 articulation for the hallux, which articular surface in Man is nearly flat : this difference is very 

 significative of the different function of the hallux in the two species ; the chief fulcrum of 

 the foot requiring a firm articulation in Man ; but in the Gorilla, great extent of motion for 

 the functions of an opposable grasping thumb. The astragalar surface is divided from that 

 for the mesocuneiform. This bone is smaller than in Man, and relatively to the ento- 

 cuneiform much smaller ; the articular surface on the inner side of the bone is interrupted or 

 divided by a narrow groove. The ectocuneiform is broader than in Man, and its lower part 

 developes a more distinct protuberance : it has two articular surfaces at the upper part of its 

 outer surface. The cuboid is smaller than in Man, especially in its antero-posterior extent ; 

 the calcaneal surface is more quadrate and flatter, and approaches externally much closer to 

 the surface for the fifth toe : the whole of the upper half of the inner side is occupied by the 

 two articular surfaces for the ectocuneiform bone, whereas there is only one articular surface 

 at the middle of the inner surface of the cuboid in Man : the surfaces for the two outer digits 

 are larger in the Gorilla : the groove crossing the fore part of the under surface of the bone 

 is deeper and better defined. 



The metatarsal of the hallux is fully as large as that in Man ; it differs in the deeper con- 

 cavity of the proximal articular surface, and in the more prominent convexity of the distal 

 one. The proximal phalanx of the hallux also equals that of Man in size ; the borders of its 

 proximal concavity are less neatly defined. The ungual phalanx is somewhat less than that 

 of Man, especially in its terminal rough tuberosity ; it is concave below instead of being 

 convex. The remaining metatarsals of the foot are much longer and stronger than in Man ; 

 the upper border is more bent. The second metatarsal has an articular facet on the inner 

 side of its base, as well as one on the outside continuous with the facet for the mesocuneiform 

 bone. The distal articulation forms a more protuberant convexity. In the fourth metatarsal 

 the articular surface on the inner side of the base is continuous with the cuboidal surface. 

 The first and second phalanges are larger and more bent. The ungual phalanges are longer 

 and narrower in proportion than in Man. 



In considering the import and value of the osteological differences between the Gorilla 

 the most anthropoid of all known brutes and Man, especially in reference to the hypo- 

 thesis of the origination of species of animals by gradual transmutation of specific charac- 

 ters, it has been urged and must be admitted that the skeleton may be modified to a certain 

 extent by the action of the muscles to which it is subservient, and that, in domesticated 

 races, the size of the animal may be brought to deviate, in both directions, from the specific 

 standard. 



By the development of the processes, ridges and crests, and also by the general pro- 

 portions of the bones themselves, especially those of the limbs, the Human anatomist judges 



