We may, in short, say that the law of adoption runs through everything, and that it may be practised on every scale. What adoption is at the hands of the family, naturalization is at the hands of the State. And the same process extends itself from adopted or naturalized individuals to large classes of men, indeed to whole nations. When the process takes place on this scale, we may best call it assimilation. Thus Rome assimilated the continental nations of western Europe to that degree that, allowing for a few survivals here and there, not only Italy, but Gaul and Spain, became Roman. The people of those lands, admitted step by step to the Roman franchise, adopted the name and tongue of Romans. It must soon have been hard to distinguish the Roman colonist in Gaul or Spain from the native Gaul or Spaniard who had, as far as in him lay, put on the guise of a Roman. This process of assimilation has gone on everywhere and at all times. When two nations come in this way into close contact with one another, it depends on a crowd of circumstances which shall assimilate the other, or whether they shall remain distinct without assimilation either way. Sometimes the conquerors assimilate their subjects; sometimes they are assimilated by their subjects; sometimes conquerors and subjects remain distinct forever. When assimilation either way does take place, the direction which it takes in each particular case will depend, partly on their respective numbers, partly on their degrees of civilization. A small number of less civilized conquerors will easily be lost among a greater number of more civilized subjects, and that even though they give their name to the land and people which they conquer. The modern Frenchman represents, not the conquering Frank, but the conquered Gaul, or, as he called himself, the conquered Roman. The modern Bulgarian represents, not the Finnish conqueror, but the conquered Slave. The modern Russian represents, not the Scandinavian ruler, but the Slave who sent for the Scandinavian to rule over him. And so we might go on with endless other cases. The point is that the process of adoption, naturalization, assimilation, has gone on everywhere. No nation can boast of absolute purity of blood, though no doubt some nations come much nearer to it than others. When I speak of purity of blood, I leave out of sight the darker questions which I have already raised with regard to the groups of mankind in days before recorded history. I assume great groups like Celtic, Teutonic, Slavonic, as having what we may call a real corporate existence, however we may hold that that corporate existence began. My present point is that no existing nation is, in the physiologist's sense of purity, purely Celtic, Teutonic, Slavonic, or anything else. All races have assimilated a greater or less amount of foreign elements. Taking this standard, one which comes more nearly within the range of our actual knowledge than the