SECRETS OF EARTH AND SEA [Illustration: DIMETRODON GIGAS, AN EXTINCT LIZARD, SEVEN FEET LONG] SECRETS OF EARTH AND SEA BY SIR RAY LANKESTER K.C.B., F.R.S. WITH NUMEROUS ILLUSTRATIONS NEW YORK THE MACMILLAN COMPANY 1920 PREFACE The present volume is, like its predecessors, "Science from an Easy Chair" (Series I and Series II) and "Diversions of a Naturalist"—mainly a revision and reprint–with considerable additions–of articles published in daily or weekly journals. The first chapter appeared originally in "The Field." The Chapters VI, XX, XXI, and XXII were published in the "Illustrated London News," under the title "About a Number of Things." The rest are some of the articles which, as "Science from an Easy Chair," I contributed, during seven years, to the "Daily Telegraph." That, to me very happy, conjunction was, like so many other happy things, necessarily interrupted by the Great War. One result of that terrible cataclysm is that not a few thoughtful writers have been led to deny the existence of what they call "Progress," meaning by that word the development of mankind from a less to a more complete attainment of moral and physical well-being. The question raised is obscured by the arbitrary use of the word "progress," since by it any movement from point to point–whether advantageous and desirable or the reverse–is described, as, for instance, in the familiar titles given by Bunyan to his book "The Pilgrim's Progress" and by Hogarth to his pictures "The Rake's Progress." Those who to-day despair of man's future limit their outlook on the past to the conventional history of some three or four thousand years. The only solid ground upon which we can base the supposition that mankind has moved from a less to a more complete attainment of moral and physical well-being and will continue to do so, exists in the ascertained facts of the past history of living things on this Earth, and of man since his earliest emergence from among the man-like apes made known to us by his stone-implements and fossilized bones. That there has been a development from lower, simpler structure to higher, more complex, more efficient structure is demonstrable, and so is the proposition that there has been in the human race a continuous development in the direction of increased adaptation to the conditions of social life and an increased control by man of those natural agencies which he can either favour when conducive to his prosperity, or on the other hand can arrest when inimical to it. "The continuous weakening of selfishness and the continuous strengthening of sympathy" (to adopt the words of the American philosopher, Fiske) are, in spite of numerous lapses and outbursts of savagery, patent features of the long history of mankind. We have no reason to doubt their continuation, whilst at the same time we must be prepared for and accept, without desponding, the ups and the downs, the disasters