"The fossils demonstrate the time to have been _long_, though we cannot say _how_ long. Thus we have generation after generation of shell-fish, that have lived and died on the spots where we find them; very often _demonstrating_ the lapse of _many years_ for a few perpendicular inches of deposit. In some beds we have large, cold-blooded reptiles, creatures of long life. In others, we have traces of ancient forests, and enormous fossil trees, with concentric rings of structure, marking the years of growth. Phenomena of this kind are repeated again and again; so that we have three or four distinct systems of deposit, each formed at a distinct period of time, and each, characterised by its peculiar fossils. Coeval with the Tertiary masses, we have enormous lacustrine deposits; sometimes made up of very fine thin laminae, marking slow tranquil deposits. Among these laminae, we can find sometimes the leaf-sheddings and the insects of successive seasons. Among them also we find almost mountain-masses of the _Indusioe tubulatoe_ [the cases of _Phryganeoe_], and other sheddings of insects, year after year. Again, streams of ancient lava alternate with some of these lacustrine tertiary deposits. "In central France, a great stream of lava caps the lacustrine limestone. At a _subsequent period_ the waters have excavated deep valleys, cutting down into the lacustrine rock-marble many hundred feet; and, at a newer epoch, anterior to the authentic history of Europe, new craters have opened, and fresh streams of lava have run down the existing valleys. Even in the Tertiary period we have thus a series of demonstrative proofs of a long succession of physical events, each of which required a long lapse of ages for its elaboration. "Again, as we pass downwards from the bottom Tertiary beds to the Chalk, we instantly find new types of organic life. The old species, which exist in millions of individuals in the upper beds, disappear, and new species are found in the chalk immediately below. This fact indicates a long lapse of time. Had the chalk and upper beds been formed simultaneously at the same period [as the supporters of the diluvial theory represent], their organic remains must have been more or less mixed; but _they are not_. Again, at the base of the Tertiary deposits resting on the Chalk, we often find great masses of conglomerate or shingle, made up of chalk-flints rolled by water. These separate the Chalk from the overlying beds, and many of the rolled flints contain certain petrified _chalk_-fossils. Now, every such fossil proves the following points:-- "1. There was a time when the organic body was alive at the bottom of the sea. "2. It was afterwards imbedded in the cretaceous deposit. "3. It became petrified; a very slow process.