For one thing, he must sit at the feet of those whose particular concern is with pre-historic man. It is well to begin here, since thus will the glamour of the subject sink into his soul at the start. Let him, for instance, travel back in thought to the Europe of many thousands of years ago, shivering under the effects of the great ice-age, yet populous with human beings so far like ourselves that they were alive to the advantage of a good fire, made handy tools out of stone and wood and bone, painted animals on the walls of their caves, or engraved them on mammoth-ivory, far more skilfully than most of us could do now, and buried their dead in a ceremonial way that points to a belief in a future life. Thus, too, he will learn betimes how to blend the methods and materials of different branches of science. A human skull, let us say, and some bones of extinct animals, and some chipped flints are all discovered side by side some twenty feet below the level of the soil. At least four separate authorities must be called in before the parts of the puzzle can be fitted together. Again, he must be taught something about race, or inherited breed, as it applies to man. A dose of practical anatomy--that is to say, some actual handling and measuring of the principal portions of the human frame in its leading varieties--will enable our beginner to appreciate the differences of outer form that distinguish, say, the British colonist in Australia from the native "black-fellow," or the whites from the negroes, and redskins, and yellow Asiatics in the United States. At this point, he may profitably embark on the details of the Darwinian hypothesis of the descent of man. Let him search amongst the manifold modern versions of the theory of human evolution for the one that comes nearest to explaining the degrees of physical likeness and unlikeness shown by men in general as compared with the animals, especially the man-like apes; and again, those shown by the men of divers ages and regions as compared with each other. Nor is it enough for him, when thus engaged, to take note simply of physical features--the shape of the skull, the colour of the skin, the tint and texture of the hair, and so on. There are likewise mental characters that seem to be bound up closely with the organism and to follow the breed. Such are the so-called instincts, the study of which should be helped out by excursions into the mind-history of animals, of children, and of the insane. Moreover, the measuring and testing of mental functions, and, in particular, of the senses, is now-a-days carried on by means of all sorts of ingenious instruments; and some experience of their use will be all to the good, when problems of descent are being tackled.