The Rock Record 57 



scepticism as an argument against accepting the 

 general idea of evolution — that the present is the 

 child of the past and the parent of the future. 



§5. The Rock Record. 



The fossil-bearing rocks are "the graveyards of the 

 buried past," and they disclose a gradual advance- 

 ment of life which testifies eloquently to the validity 

 of the evolution idea. It is usual to speak of these 

 illustrative facts as "evidences of evolution," and 

 after the saving clauses of the previous paragraph 

 the useful term may be retained. 



The rock record, battered and incomplete as it is, 

 shows clearly that as the earth grew in aeons there was 

 a successive emergence of nobler and finer forms of 

 life. There was a time when the only backboned ani- 

 mals were the fishes in the waters under the earth. 

 Ages passed, and Amphibians appeared, with fingers 

 and toes, lungs and a voice, and many other new 

 acquisitions. Then came the Golden Age of Reptiles, 

 confirming the conquest of the dry land which Am- 

 phibians had begun. For a long time these Reptiles 

 represented the topmost branches of the genealogical 

 tree, for there was no hint of birds or mammals. 

 Eventually these appeared, and the ascent continued, 

 until at last arose the man. 



In early Darwinian days the gradual emergence of 

 more differentiated and more integrated forms of life 

 was recognized as a great fact; and detailed fossil 

 series were discerned of snails and cuttlefishes, of 



