CREATION BY EVOLUTION
itants of trees, and these belonged to a very ancient group, retaining certain primitive traits of limbs and teeth which left them far behind the others in evolutionary status. But out of these, largely through mental supremacy, were to come our forebears and, later, actual humanity itself.
Certain recorded links couple lines which to-day are so divergent that students of recent animals would hardly imagine their relationship. Compare the manatee, of spindle-like body, broad swimming tail, flipper-like fore limbs, and no visible hind limbs at all, with the majestic elephant, conspicuous for his peculiar features of limbs, head, and trunk. What community of structure do they show? And yet there has come out of the Libyan desert of Egypt a fossil form that is neither one nor the other but partakes somewhat of the nature of both—a synthetic swamp-dwelling type, whose descendants came to the parting of the ways and went severally to the sea and to the land—to grotesque aquatic efficiency on the one hand and to noble terrestrial majesty on the other. Here the link has been found. Were it lost, who could tell the tale of this strange kinship?
One of the most completely known of all evolutionary chains is that of the horse-like forms, though here again the hypothetical five-toed ancestor is still undiscovered. We could, however, restore him in detail, so complete is our evidence of the course of equine evolution, and, if the chain includes other missing links we can formulate their characteristics with mathematical certainty, as well as their distribution in time and place. Our material for tracing the horses is so abundant that it resolves itself not into a single chain, but into many, all of which have arisen from the original stock to follow lines that may be closely parallel, or, again, widely divergent, but invariably in response to climatic and vegetative environment. Most of these chains
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