What is true of the dog is true also, to a large extent, of the cat, cow, horse, sheep, goat, fowl, and other domestic animals. Serene and peaceful puss is the tranquillised descendant of the wild cat of Egypt, one of the most untamable of all animals. The migratory instinct, so strong in wild water-fowl, is almost absent from our geese and ducks, as is the fighting propensity (prominent in the Indian jungle-bird) from most varieties of the domesticated chicken. There are now as many as a hundred different kinds of domesticated animals, and there is scarcely one of these animals that has not been profoundly changed in character during the period of its domestication. There are much greater changes in some races than in others. Some races have been much longer in captivity than others. And then, too, there is great difference in the degree of plasticity in different races, the races of ancient origin being much more fixed in their psychology than those of more recent beginnings. In some races, too—as in the sheep—the selections made by man have been made primarily with reference to certain physical qualities, and in these cases the mental qualities have been only incidentally affected. In Polynesia, where it is selected for its flavour instead of for its fleetness or intelligence, the dog is said to be a very stupid animal. But in most cases of domestication the changes wrought by selection in the mental make-up of the race have been fully as great as the changes in body, and in some instances much greater. And the process by which these great changes in psychology have been effected is in principle identically the same as that by which mental evolution in general is assumed to have been brought about. History everywhere has come out of the night, out of the deep gloom of the unrecorded. But it has not leaped forth like lightning out of the darkness. It has dawned, night being succeeded by the amorphous shadows of legend and tradition, and these in turn by the attested events of true history. Almost every civilised people can trace back its genealogy to a time when it was represented on the earth by one or more tribes of savage or half-savage ancestors. The Anglo-Saxons go back to the Angles, Saxons, and Jutes, three semi-savage tribes who came to England from the borderlands of the Baltic fourteen or fifteen centuries ago. The French are the descendants of the Gauls, who formed the scattered population of warring and superstitious tribes referred to by Julius Caesar in the opening lines of his ‘Commentaries.’ The blue-eyed Germans came from the Cimbri, the Goths, and the Vandals, those bold, wild hordes who charged out of the north to battle with the power of Rome. And all of the Aryan races—English, German, Italian, Scandinavian, Russian, Roman, Greek, and Persian—trace their ancestry back, by means of common languages and legends, to a time when they were wandering tribes of nomads tenting somewhere on the plains of transcaspian Asia.