Page:Popular Science Monthly Volume 42.djvu/465

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447
MAN IN NATURE.

other of the rival systems of classification, some separating man from the Primates as a special order, others isolating him among the Primates as a suborder or family, and others including man and the anthropoids together. We said we must draw up a general balance sheet. As the divergences sometimes pertain to what we consider only one aspect of the problem, it was necessary to regard all the aspects; and we have done this. We have given our conclusions respecting each characteristic, respecting each group of characteristics. Our present purpose is only to summarize the most affirmative of them, those that concern the brain and the skull, the adaptation of the body, and particularly of the lower limbs, to the bipedal attitude, and of the upper limbs to prehension.

In the general type of the brain we have only determined common characteristics in what concerns the profound structure.

The type of the convolutions appears to us rudimentary in the lower Primates; gradually developing, already characterized in the papion; absolutely established, according to Broca, in the gibbon; becoming more complicated in passing from the anthropoids to man, but without appreciable change to a characteristic which must not be neglected, the transformation of the third frontal convolution. Man alone presents the speech centre, a characteristic corresponding with the acquisition of the faculty of articulate language. The conclusion results that, even without regard to the richness of man's convolutions, there still exists between him and the anthropoids a difference—capital in its physiological consequences—which forbids any relation on this ground between them and him. As to the volume of the brain the conclusion is express. It is triple in man and leaves the anthropoids with the other monkeys.

The consequence of this increase of volume, general, but predominant in the anterior lobes, is the complete transformation of the skull. While it retains some of the characteristics peculiar to the Primates in general, which it had already assumed, it becomes what we know it in existing man, profoundly different in all its characteristics from the skull of the anthropoids, including the craniometrical characteristics. The face itself is transformed. All bends before the supremacy of the organ which, near or far, governs the whole human organism and separates it completely from the anthropoids.

The hand is the second fundamental characteristic of man, but a characteristic common to all the Primates, starting with the first ones and advancing continually toward perfection. With the monkeys, the forearm comes to the aid of the hand; with the anthropoids, the whole fore limb concurs in the function; in man it acquires its final degree of precision. Till then it was