CREATION BY EVOLUTION
same structure, the same development, and in the shark the one passes over the lips into the other.
Gradually, through long ages, body-scales like those of the shark were replaced by scales of different structure, and these directly or indirectly gave rise to reptilian scales, birds' feathers, and mammalian hair. But all through these changes the ancient scales in the mouth—the teeth—have remained essentially the same. Existing birds have lost them, but they were possessed by their ancestors, as we know from the fossil birds of both the Old World and the New.
The story of the mammals—our own branch—is more completely represented by animals alive to-day because of the preservation in Australia, cut off by sea from the stress and rush of life in other great land areas, of the duck-billed platypus (Ornithorhynchus) and the echidna, which is found also in New Guinea. Thus preserved from extinction, these remarkable animals have come down to us, descended from a link that connects the mammals with some primitive reptilian or pre-reptilian ancestor. Their temperature is much lower than that of mammals; their skeleton shows strong reptilian affinity; above all, they lay eggs like reptiles and birds, but they suckle their young by a primitive form of mammary gland. Yet these ancient forms, descendants of an ancestor through which the mammals received their teeth, are now, both of them, toothless. The echidna, feeding by means of its tongue, like the true ant-eaters of South America, is entirely toothless; the platypus has hard, toothlike plates for crushing the insects and mollusks of the streams in which it lives. These plates are really hardened gums; they have nothing of the structure of teeth. So the evidence looked for was wanting just where we should chiefly expect to find it. The evolutionist was nevertheless confident that these animals or their immediate ancestors
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