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In proof of this he called attention to the entire absence of Ammonites, Belemnites, Brachiopoda, Echinodermata, Corals, and other marine fossils, so characteristic of the Cretaceous rocks above, and of the Oolitic strata below, and to the presence in the Weald of Paludinae, Melaniae, Cyrenae, and various fluviatile shells, as well as the bones of terrestrial reptiles and the trunks and leaves of land-plants.
Some of the convulsions caused by the fiery mass within threw up rock above the surface of the waters, and thus the dry land began to appear. Islands were formed, and immediately land-plants made their appearance, of excessive luxuriance, under the tropical temperature that still prevailed all over the globe, and began their office of absorbing carbon, and storing it up for future use.
As the Upper Cretaceous rocks of Europe are, for the most part, of purely marine origin, and formed in deep water usually far from the nearest shore, land-plants of this period, as we might naturally have anticipated, are very rarely met with.
The lichen and the moss reared their tiny fronds on the first rocks that emerged from the deep; land-plants, evolving the various forms of fruit and flower, next arose, the Upas and the bread-fruit tree, the gnarled oak and the lofty cedar. Animal life appeared when the granary of nature was ready with its supplies.
The leaves show beneath the magnifier beautiful adaptations of structure. They are not, like those of land-plants, constructed with deep veins to receive the rain and conduct it to the stem, but are smooth and glossy, and of even surface.
Land-plants and animals came next, though of a low type; continually advancing orders of beings, reptiles, birds, and mammifers, suited to the improved condition of things, successively appeared, until, at the latest epoch, man entered upon the scene, the head of animated nature as at present constituted, with powers and capacities well adapted for the full enjoyment of the augmented riches of the earth.
As to this there is no dispute; nor, in fact, about the climate from the Cambrian to the Permian. In the Silurian we have "much to suggest uniformity of climate" in fact, we have just the same evidence for it and in the Devonian, when land-plants abound and afford better evidence, we find the same climatic equality of living things in the most different latitudes.
Those growing in the shallow water of the shore are green, like land-plants, because the sunlight reaches them. Only part of the light can pass through deep water; and so, in these shady places, the sea-weed is reddish in colour.
If you dive still farther, into the dark depths of the sea, you find beds of ooze and slime, and rocks and weird fishes, but no plants. Why is this? Like the land-plants, these sea-plants must have light. They cannot grow in the blackness of very deep water. Can you guess why some sea-weeds are green and others red?
For the numerous circumstances in which vegetable buds are analogous to animals, the reader is referred to the additional notes at the end of the Botanic Garden, Part I. It is there shewn, that the roots of vegetables resemble the lacteal system of animals; the sap-vessels in the early spring, before their leaves expand, are analogous to the placental vessels of the foetus; that the leaves of land-plants resemble lungs, and those of aquatic plants the gills of fish; that there are other systems of vessels resembling the vena portarum of quadrupeds, or the aorta of fish; that the digestive power of vegetables is similar to that of animals converting the fluids, which they absorb, into sugar; that their seeds resemble the eggs of animals, and their buds and bulbs their viviparous offspring.
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