Aboriginal America
Book Excerpt
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Evidence of Fossil Remains
But we have still more conclusive evidence than this derived from ancient monuments of the very great permanence of the characteristics by which different species of plants and animals are distinguished from each other, in the fossil remains which exist in the strata of the earth. By means of these our observations upon the forms of vegetable and animal life which have existed upon our globe may be carried back to an immense antiquity, and extended over so vast a number and variety of species as to furnish us, as it has always been supposed, with all the means of information on this subject that can be desired. It has been thought to be fully proved by these observations that every species which exists upon the earth remains unchanged so long as it exists. When at length its period has expired, it disappears from the field, while new ones are continually arising