In Europe man can be studied only as he has been moulded by a thousand external influences, and by the intermixture of many dissimilar races. The most recent terms of ethnological classification, the Xanthocroi and Melanochroi, are based on the assumed interblending of widely dissimilar races in times long anterior to any definite chronology. There was a time, as is assumed, when the sparsely peopled areas of Europe were occupied by a population still imperfectly represented by the Finns, the Lapps, and the Basques. Those are supposed to be surviving fragments of a once homogeneous population in prehistoric centuries. On this the great Aryan migration intruded in successive waves of Celtic, Slavic, Hellenic and Teutonic invaders, not without considerable intermixture of blood. Such is the great ethnical revolution by which it is assumed that Europe was recolonised from the same source from whence India and Persia derived their ancient civilised and lettered races. The Finnic hypothesis, and the once favoured idea of an Asiatic cradleland for the whole so-called Aryan races, have been greatly modified by later research. Community of language is no longer accepted as necessarily involving a common ethnic origin. But the results in no way affect the general conclusion as to the displacement of a succession of barbarous races by the historic races of Europe long before the Christian era. The year 1492 marks the beginning of an analogous ethnical revolution by which the Aryan, or Indo-European stock intruded, in ever-increasing numbers, on the aboriginal populations of the New World. The disparity between the first Celtic or other Aryan immigrants into Europe and the aborigines whom they encountered there was probably less than that which separated the first American colonists from the Red Indian savages whom they displaced. In both cases it was the meeting of cultured races with rude nomads whom they were prone to regard with an aversion or contempt very different from the repellent elements between conquering and subject nations in near equality to each other. The disparity, for example, between the native Briton and the intruding Saxon, or between the later Anglo-Saxon and the intruding Dane or Northman, was sufficiently slight to admit of ready intermixture, ultimately, in spite of their bitter antagonism. Nor was even the civilised Roman separated by any such gulf from the Gaul or German who bowed to the Imperial yoke, and exchanged their independence for Roman citizenship. But other elements have also to be kept in view. The pioneers of emigration are not, as a rule, the most cultured members of the intruding race; while the disparity in the relative numbers of the sexes inevitably resulting from the conditions under which any extensive migration takes place forms an effective counterpoise to very wide ethnical differences. In every case of extensive immigration, with the excess of males and