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, feed- 

 ing by means of its tongue, like the true ant-eaters of South 

 America, is entirely toothless; the platypus has hard, tooth- 

 like plates for crushing the insects and moUusks 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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