afford to retire without a blow from that tenaciously defended bastion of their main position. Hence the evolutionary concept had its hardest fight to wage over the biological field; and when that field was once fairly won, it had little more to fear from banded preconceptions and established prejudices in any other portion of the wide territory it claimed for its own. In the second place, biological evolution, firmly established by Darwin on a safe, certain, and unimpeachable basis, led naturally and almost inevitably to all the other innumerable applications of the evolutionary method, in the domains of psychology, sociology, philology, political thought, and ethical science. Hence the immediate and visible results of its promulgation have been far more striking, noticeable, and evident than those which followed the establishment of the evolutionary conception in the astronomical and geological departments. It was possible to accept cosmical evolution and solar evolution and planetary evolution, without at the same time accepting evolution in the restricted field of life and mind. But it was impossible to accept evolution in biology without at the same time extending its application to psychology, to the social organism, to language, to ethics, to all the thousand and one varied interests of human life and human development. Now, most people are little moved by speculations and hypotheses as to the origin of the milky way or the belt of Orion; they care very slightly for Jupiter's moons or Saturn's rings; they are stolidly incurious as to the development of the earth's crust, or the precise date of the cretaceous epoch; but they understand and begin to be touched the moment you come to the practical questions of man's origin, nature, and history. Darwinism compelled their attention by its immediate connection with their own race; and the proof of this truth is amply shown by the mere fact that out of all the immense variety of Charles Darwin's theories and ideas, the solitary one which alone has succeeded in attaching to itself the public interest and public ridicule is the theory of man's ultimate descent from a monkey-like ancestor. Popular instinct, here as elsewhere profoundly true at core in the midst of all its superficial foolishness, has rightly hit upon the central element in the Darwinian conception which more than any other has caused its fruitful and wonderful expansion through every fertile field of human enquiry. In short, it was Darwin's task in life to draw down evolution from heaven to earth, and to bring within the scope of its luminous method all that is most interesting to the uninstructed and unsophisticated heart of the natural man.