We must, in future geological study, trace back the gradually decreasing brain of former races to a time when the body as well begins materially to differ, if we would wish to reach the starting-point of the human family. Before that time man had not mind enough to preserve his body from change. From this point, however, we shall probably see that, while all other forms of animal life changed again and again, man's physical character became fixed and almost immutable, advance taking place only in his mental and moral characteristics, with which are united modifications of the brain, as well as of the head and face, parts that are immediately connected with the brain and the medium of the most refined emotions. By man's superior sympathetic and moral feelings, he becomes fitted for the social state. There is one feature, however, in which natural selection will still act upon him--namely, the color of the skin, which, as Mr. Darwin has shown, is correlated with constitutional peculiarities, liability to certain diseases being often accompanied by marked external characteristics; so that, in certain countries, certain tints would be likely to be weeded out, and certain other tints, with which, again, color and texture of the hair seem to be associated, would be established by natural selection. Natural selection has no power "to produce modifications which are in any degree injurious to their possessor, and Mr. Darwin uses the strong expression that a single case of this kind would be fatal to his theory. If, therefore, we find in man any characters which all the evidence we can obtain goes to show would have been actually injurious to him on their first appearance, they could not possibly have been produced by natural selection. Neither could any specially developed organ have been so produced if it had been merely useless to its possessor, or if its use were not proportionate to its degree of development. Such cases as these would prove that some other law, or some other power, than natural selection, had been at work. But if, further, we could see that these very modifications, though hurtful or useless at the time when they first appeared, became in the highest degree useful at a much later period, and are essential to the full moral and intellectual development of human nature, we should then infer the action of mind, foreseeing the future and preparing for it, just as surely as we do when we see the breeder set himself to work with the determination to produce a definite improvement in some cultivated plant or domestic animal"; we should infer a creation by law. Skull-measurement shows that the brain of the savage was, and is, larger than it needs to be, and "capable, if cultivated and developed, of performing work of a degree and kind far beyond what he ever requires it to do." In evidence of this, Wallace cites the measurements of Esquimaux skulls and the testimony of Paul