tion. On the opposite side of the globe the western hemisphere points south between the two seas.
Having located the four races in their respective habitats, we should next determine how each racial region was originally occupied, and then note the ethnic effects produced by geographic peculiarities.
The human species was differentiated from the other anthropoids within Indo-Malaysia, where the climate was moist and warm and the surface of the ground covered with a tropical forest growth. Such were the surroundings that impressed themselves upon primeval man and established the original type. These conditions were continued on either side of the cradle-land toward the south along the equatorial belt of the eastern hemisphere, which then stretched uninterruptedly from the west coast of Africa, across the now partially submerged Indo-African continent, into Melanesia and Australia. The shifting of the thermal equator north and south of the geographical equator no doubt caused the climate of this intertropical belt to vary slightly during the ice-age; but after the final retreat of the glaciers no further changes occurred; so that, ever since, the environmental conditions of the eastern-equatorial region have remained to all intents and purposes the same as they were in tertiary times. The Negro descendants of the original inhabitants of these parts have thus been subjected since time immemorial to somewhat the same external influences as impressed themselves upon primeval man. It is natural, therefore, that the blacks should conserve the conspicuous characteristics of the ape-like ancestor and resemble the human prototype more closely than any other people. Ethnically the Negroes are considered the lowest of the four races of man; while geographically they may be characterized as the children of the tropical forest. There are, to be sure, minor differences among them, arising from different lines of heredity, variations of environment, migration and miscegenation; so that from the primitive Pygmy people living in the recesses of the tropical forest, the line of ethnic evolution may be traced through the pure Negroes, who occupy the central equatorial belt, to the mixed Negroid types which have come into contact with other races on the borders of the region. But despite these differences the Blacks may still be regarded as ethnically similar and grouped together under one racial category; for, if we confine ourselves to general characteristics, the typical Negro can readily be distinguished from his human fellows by his black skin; his short curly hair, which is flat in cross section; his long head with protruding jaws, his flat foot, his broad nose and his round black eyes.
The rest of the races of mankind were differentiated within the northern hemisphere. Being affected from the first by the varying environment of the glacial era, these northern emigrants were influenced by different conditions from those to which their ancestors