That was the most ornamental and spectacular age in the whole history of animal life on this earth. Nothing so fantastic has ever lived, before or since. One beast had a crest of many pointed plates jutting out of its high humped back from head to tail. Several had two or three horns, on forehead and snout. One had a full suit of bony armor plates, including a movable shield over each eye. Another had a bill like a duck, and a towering dome of a skull that gives an impression of high intellect; but his brain, like that of all the rest, was ridiculously small. There were hundreds of different kinds of these quaint animals roaming about here at the same time. Even that is not the earliest scene of Western life we can see when we open the telescope of imagination and look back through the ages past. Look back far enough, and we see the hot earth spinning through space, a soft and fluid ball,—red-hot, only we cannot see the color, for a thick cloud of vapor covers all. As the earth cools, it shrinks, wrinkling and crinkling. The parts of its skin that rise make continents and islands, the parts that sink make seas and lakes. It goes on shrinking, and its shape changes constantly. A sea-bottom rises, and becomes land; land sinks, and is covered by sea. Up and down, up and down, for millions of years. Little beasts appeared in the sea. High up in the Rocky Mountains we find them by countless thousands—the trilobites, related to the crabs,—their shapes preserved and moulded in the solid stone. But that stone, when they lived and died, was soft mud at the bottom of the sea. There were no Rocky Mountains then. The oldest mountains in this part of the world are nearer the coast. They are worn down and rounded now; for as soon as a mountain is raised it begins to wear away, split by frost, falling in landslides, and washed down by rain. Even when the giant lizards browsed and played and fought in the jungle, there were no Rockies yet. The giant lizards came, and passed away. The earth still shrank, and threw up more wrinkles,—the Rocky Mountains at last rising out of the sea. They are still so new that their ridges and edges and peaks have not yet lost their sharpness, yet so many thousand years old that their uppermost rocks, worn away to sand and carried down in rivers to the plain, have had time to bury the lizards many feet deep. They have buried, too, the tropical palms and ferns and reeds, and pressed them into coal, which we dig up and burn.