I. DISTINCTIVE CHARACTERISTICS OF MAN.
By Cuvier and nearly all modern zoologists, the various races of mankind are included under one genus, Homo ; and this genus takes rank, in the classification of Mam malia, as a distinct order, BIMANA, of which it is the sole representative. Of all the cha racters which distinguish Man from the in ferior Mammalia, the possession of two hands is doubtless the most easily recognised, and at the same time the most intimately related to the general organisation of the body ; and there is none, therefore, which could be more appropriately selected as the basis of a dis tinctive designation for this order. At first sight it might be considered that the pos session of only two hands, whilst Apes and Monkeys and their allies are designated as possessing four, is a character of inferiority ; but such is not really the case ; for none of these four hands are adapted to the va riety of actions of which those of man are capable, and they are all in some degree re quired for support ; so that whilst in the higher forms of the Quadrumanous order, the extremities present a certain approximation in structure to those of man, in the lower they gradually assimilate to the ordinary quadrupedal type. " That," says Cuvier, " which constitutes the hand, properly so called, is the faculty of opposing the thumb to the other fingers, so as to seize upon the most minute objects ;- a faculty which is car ried to its highest degree of perfection in Man, in whom the whole anterior extremity is free, and can be employed in prehension." The peculiar prehensile power possessed by man is chiefly dependent upon the size and power of the thumb ; which is more developed in Man than it is in the highest apes. The thumb of the human hand can be brought into exact opposition to the extremities of all the fingers, whether singly or in combination ; whilst in those Quadrumana which most nearly ap proach man, the thumb is so short, and the fingers so much elongated, that their tips can scarcely be brought into opposition ; and the thumb and fingers are so weak, that they can never be opposed to each other with any de gree of force. Hence, although admirably adapted for clinging round bodies of a certain size, such as the small branches of trees, &c.,
the extremities of the Qnadrumana can nei ther seize very minute objects with such pre cision, nor support large ones with such firmness, as are essential to the dexterous per formance of a variety of operations, for which the hand of Man is admirably adapted. There is much truth, then, in Sir C. Bell's remark, that "we ought to define the hand as belong ing exclusively to man." There is in him, what we observe in none of the Mammalia which approach him in other respects, a com plete distinction in the functional character of the anterior and posterior extremities ; the former being adapted for prehension alone, and the latter for support and progression alone; and thus each function is performed in a much higher degree of perfection, than it can be when two such opposite purposes have to be united. For not only is the hand of man a much more perfect prehensile in strument than that of the orang or chim panzee, but his foot is a much more perfect organ of support and progression than theirs, being adapted to maintain his body in an erect position, alike during rest and whilst in motion, —an attitude which even the most anthropoid apes can only sustain for a short time, and with an obvious effort. The arm of the higher apes has as wide a range of motion as that of man, so far as its articu lation is concerned ; but it is only when the animal is in the erect attitude, that the limb can have free play. Thus the structure of the whole frame must be conformable to that of the hand, in the way that we find it to be in man, in order that this organ may he advan tageously applied to the purposes which it is' adapted to perform. But it cannot be said with truth (as some have maintained) that Man owes his superiority to his hand alone ; for without the mind by which it is directed, and the senses by which its operations are guided, it would be a comparatively valueless in strument. Alan's elevated position is due to the superiority of his mind and of its ma terial instruments conjointly ; for if destitute of either, the human race must be speedily ex tinguished altogether, or reduced to a very subordinate grade of existence.