In support of this conclusion we are now about to bring forward a new and independent argument founded on the testimony of Fossil Remains. An eminent writer has summed up in a few words the value and importance of Fossil Remains in reference to Geological theory. “At present,” he says, “shells, fishes, and other animals are buried in the mud or silt of lakes and estuaries; rivers also carry down the carcases of land animals, the trunks of trees, and other vegetable drift; and earthquakes submerge plains and islands, with all their vegetable and animal inhabitants. These remains become enveloped in the layers of mud and sand and gravel formed by the waters, and in process of time are petrified, that is, are converted into stony matter like the shells and bones found in the oldest strata. Now, as at present, so in all former time must the remains of plants and animals have been similarly preserved; and, as one tribe of plant is peculiar to the dry plain, another to the swampy morass; as one family belongs to a temperate, another to a tropical region, so, from the character of the embedded plants, we are enabled to arrive at some knowledge of the conditions under which they flourished. In the same manner with animals: each tribe has its locality assigned it by peculiarities of food, climate, and the like; each family has its own peculiar structure for running, flying, swimming, plant-eating, or flesh-eating, as the case may be; and by comparing Fossil Remains with existing races, we are enabled to determine many of the past conditions of the world with considerable certainty.”[68] On this branch of our subject we do not mean to offer much in the way of argument strictly so called. We shall content ourselves with a simple statement of facts, and leave them to produce their own impression. It will be necessary at the outset to explain some technical matters, that what we have to say hereafter may be the better understood: and if in this we are somewhat dry and tiresome, we will try to make amends by the curious and interesting story of Nature’s long buried works, which we hope in the sequel to unfold. * * * * * When the word _Fossil_ was first introduced into the English language, it was employed to designate, as the etymology suggests, whatever is _dug out of the earth_.[69] But it is now generally used in a much more restricted sense, being applied only to the remains of plants and animals embedded in the Crust of the Earth and there preserved by natural causes. When we speak of remains, we must be understood to include even those seemingly transient impressions, such as foot-prints in the sand, which having been made permanent by accidental circumstances, and thus engraved, as it were, on the archives of Nature, now bear witness to the former existence of organic life.