"Identical in the physical processes by which he originates--identical in the early stages of his formation--identical in the mode of his nutrition before and after birth, with the animals which lie immediately below him on the {204}scale--Man, if his adult and perfect stature be compared with theirs, exhibits, as might be expected, a marvellous likeness of organisation. He resembles them as they resemble one another--he differs from them as they differ from one another." (_Huxley._) On comparing his external form and internal organisation with that of all the other known zoological forms, he is found to fit no niche in the scale of classification, founded on the same principles of likeness and dissimilitude as applied to them, except in the vicinity of the Gibbons, the Orangs, the Gorillas, and the Chimpanzees, of whose order--the Primates--he forms only an additional though higher Family, solely on his structural characters and entirely apart from those intangible mental attributes which remove him supremely above all other creatures. Unbridged as is the chasm between the Ape and Man, "the structural differences which separate Man from the Gorilla and the Chimpanzee, are not so great as those which separate the greater from the lower Apes." (_Huxley._) Of the three higher Apes, the Chimpanzees are those which appear to approach Man most closely; but he is distinguished from them and from all the other members of the _Simiidæ_ by his body being supported in the erect position upon the outer edge of a broad, arched, short-toed foot, articulated at right angles to the leg. This foot has a prominent heel and a stout great-toe, longer than all the digits, except the second, but lying parallel and not opposable to them, or capable of being moved away from them, because of the flat unrounded articular surface of the ento-cuneiform bone of the ankle. His back-bone has a strongly-marked, open S-shaped curvature, with its concavity in the lower back, giving it its elasticity and breaking any shock which might be transmitted otherwise to the brain through the jolt of walking in the vertical position. His arms are {205}proportionately much shorter than the legs, and also the spine; the thumb is also longer in proportion than in the Apes, and, as the fingers have all separate movements, the hand is thus better able to be adjusted to minute operations. The head in Man is equipoised on the vertebral column just under the centre of its mass, and is thus easily supported and moved, whereas, in all lower forms of Vertebrates, it is placed further and further from the centre towards the back, with its weight thrown towards the front. In Man the skull cavity, not intruded upon and diminished by the roof of the orbits, is characteristically high and arched, its capacity being twice as great as any Ape's; still the difference in the cranial capacity of different races of Man is much greater absolutely than that between the highest Ape and the lowest Man.