Whenever a low race is preserved under conditions of life that exact a high level of efficiency, it must be subjected to rigorous selection. The few best specimens of that race can alone be allowed to become parents, and not many of their descendants can be allowed to live. On the other hand, if a higher race be substituted for the low one, all this terrible misery disappears. The most merciful form of what I ventured to call "eugenics" would consist in watching for the indications of superior strains or races, and in so favouring them that their progeny shall outnumber and gradually replace that of the old one. Such strains are of no infrequent occurrence. It is easy to specify families who are characterised by strong resemblances, and whose features and character are usually prepotent over those of their wives or husbands in their joint offspring, and who are at the same time as prolific as the average of their class. These strains can be conveniently studied in the families of exiles, which, for obvious reasons, are easy to trace in their various branches. The debt that most countries owe to the race of men whom they received from one another as immigrants, whether leaving their native country of their own free will, or as exiles on political or religious grounds, has been often pointed out, and may, I think, be accounted for as follows:--The fact of a man leaving his compatriots, or so irritating them that they compel him to go, is fair evidence that either he or they, or both, feel that his character is alien to theirs. Exiles are also on the whole men of considerable force of character; a quiet man would endure and succumb, he would not have energy to transplant himself or to become so conspicuous as to be an object of general attack. We may justly infer from this, that exiles are on the whole men of exceptional and energetic natures, and it is especially from such men as these that new strains of race are likely to proceed. INFLUENCE OF MAN UPON RACE. The influence of man upon the nature of his own race has already been very large, but it has not been intelligently directed, and has in many instances done great harm. Its action has been by invasions and migration of races, by war and massacre, by wholesale deportation of population, by emigration, and by many social customs which have a silent but widespread effect.