These physical forces have worked as slowly and silently in sculpturing the landscapes as the biological laws have worked in evolving man from the lower animals, or the vertebrates from the invertebrates. The rains, the dews, the snows, the winds--how could these soft, gently careering agents have demolished these rocks and dug these valleys? One would almost as soon expect the wings and feet of the birds to wear away the forests they flit through. The wings of time are feathered also, and as they brush against the granite or the flinty sandstone no visible particle is removed while you watch and wait. Come back in a thousand years, and you note no change, save in the covering of trees and verdure. Return in ten thousand, and you would probably find the hills carrying their heads as high and as proudly as ever. Here and there the face of the cliff may have given way, or a talus slid into the valley, or a stream or river changed its course, or sawed deeper into the rock, and a lake been turned into a marsh, or the delta of a river broadened--minor changes, such as a shingle from your roof or a brick from your chimney, while your house stands as before. In one hundred thousand years what changes should we probably find? Here in the Catskills, where I write, the weathering of the hills and mountains would probably have been but slight. It must be fifty thousand years or more since the great ice-sheet left us. Where protected by a thin coat of soil, its scratches and grooves upon the surface rock are about as fresh and distinct as you may see them made in Alaska at the present time. Where the rock is exposed, they have weathered out, one eighth of an inch probably having been worn away. The drifting of the withered leaves of autumn, or of the snows of winter over them, it really seems, would have done as much in that stretch of time. Then try to fancy the eternity it has taken the subaerial elements to cut thousands of feet through this hard Catskill sandstone! No, the evolution of the landscape, the evolution of the animal and vegetable kingdoms, the evolution of the suns and planets, involve a process so slow, and on such a scale, that it is quite unthinkable. How long it took evolution to bridge the chasm between the vertebrate and the invertebrate, between the fish and the frog, between the frog and the reptile, between the reptile and the mammal, or between the lowest mammal and the highest, who can guess? But the gulf has been passed, and here we are in this teeming world of life and beauty, with a terrible past behind us, but a brighter and brighter future before us. X "THE WORM STRIVING TO BE MAN"