Page:Early Man in Britain and His Place in the Tertiary Period.djvu/29



the many fields of inquiry opened out by the intense mental activity of this century, there is none which promises to be more fruitful than that which has been won by the joint labours of the geologist, the student of prehistoric archæology, and the historian. The geologist, beginning his story of the earth at the time when the rains first descended and the seas first began to beat on the coast-lines, has laid, as it were, in a map before us the revolutions in climate and geography that it has undergone. He tells of continents submerged, and of ocean bottoms lifted up to become mountains; and he points out to us that side by side with the ever-changing conditions of life there were corresponding changes in the living forms. Group after group of animals and