For not only were they deposited in shallow water; a great deal of them, probably, near river-mouths, and by the force of violent currents, as the irregularity of their lower bed proves: but there is hardly a plant or animal found in the chalk itself, which is found in the gravels, sands, or clays above it. The shells are all new species; unseen before in this planet. The vegetables, as far as we know them, are all different from anything found in the chalk, or in the beds below it. God Almighty, for His own good pleasure, has made all things new. It is a very awful fact; but it is a very certain one. Several times, in the history of our planet, has the Lord God fulfilled the words of the Psalmist: "Thou takest away their breath, they die, and return again to their dust. "Thou sendest forth thy breath, they are made: and thou renewest the face of the earth." But in no instance, perhaps, is the gulf so vast; is the leap from one world to another so sheer, as that between the chalk and the London clay above it. But how do I know that there was a shore-line here? And how do I know that the chalk was covered with sand-beds? I know that there was a shore-line here, from this fact. If you will look at the surface of the chalk, where the sands and clays lie on it, you will find that it is not smooth; that the beds do not rest conformably on each other, as if they had been laid down quietly by successive tides, while the chalk below was still soft mud. So far from it, the chalk must have become hard rock, and have been exposed to the action of the sea waves, for centuries, perhaps, before the sands began to cover it. For you find the surface of the chalk furrowed, worn into deep pits, which are often filled with sand, and gravel, and rounded lumps of chalk. You may see this for yourselves, in the topmost layer of any chalk-pit round here. You may see, even, in some places, the holes which boring shells, such as work now close to the tide-level, have made in it; all the signs, in fact, of the chalk having been a rocky sea-beach for ages. The first bed which you will generally find upon the water-worn surface of the chalk is a layer of green-sand and green-coated flints. Among these are met with in many places beds of a great oyster, now unknown in life. I cannot say whether there are any here; but at Reading, to the east of Farnham, at Croydon, and under London, they are abundant. There must have been miles and miles of oyster-bed at the bottom of that Eocene sea; among the oyster-beds, beds of a peculiar pebble, which we shall see in our gravel-pit.