1. According to both records, the causes which at present regulate the distribution of light, heat, and moisture, and of land and water, were, during the whole of this period, much the same as at present. The eyes of the trilobite of the old Silurian rocks are fitted for the same conditions with respect to light with those of existing animals of the same class. The coniferous trees of the coal measures show annual rings of growth. Impressions of rain-marks have been found in the shales of the coal measures and Devonian system. Hills and valleys, swamps and lagoons, rivers, bays, seas, coral reefs and shell beds, have all left indubitable evidence of their existence in the geological record. On the other hand, the Bible affirms that all the earth's physical features were perfected on the fourth day, and immediately before the creation of animals. The land and the water have undergone during this long lapse of ages many minor changes. Whole tribes of animals and plants have been swept away and replaced by others, but the general aspect of inorganic nature has remained the same. 2. Both records show the existence of vegetation during this period; though the geologic record, if taken alone, would, from its want of information respecting the third day, lead us to infer that plants are no older than animals, while the Bible does not speak of the nature of the vegetation that may have existed on the fifth day. 3. Both records inform us that reptiles and birds were the higher and leading forms of animals, and that all the lower forms of animals co-existed with them. In both we have especial notice of the gigantic Saurian reptiles of the latter part of the period; and if we have the remains of a few small species of mammals in the Mesozoic rocks, these, like a few similar creatures apparently included under the word _sheretz_ in Leviticus, are not sufficiently important to negative the general fact of the reign of reptiles.[95] 4. It accords with both records that the work of creation in this period was gradually progressive. Species after species was locally introduced, extended itself, and, after having served its purpose, gradually became extinct. And thus each successive rock formation presents new groups of species, each rising in numbers and perfection above the last, and marking a gradual assimilation of the general conditions of our planet to their present state, yet without any convulsions or general catastrophes affecting the whole earth at once. 5. In both records the time between the creation of the first animals and the introduction of the mammalia as a dominant class forms a well-marked period. I would not too positively assert that the close of the fifth day accords precisely with that of the Mesozoic or secondary period. The well-marked line of separation, however, in many parts of the world, between this and the earlier tertiary rocks succeeding to it, points to this as extremely probable.