DARWIN 109 



Cuvier, was so great a genius that it seemed quite 

 impossible that he had made a mistake. Before 

 twenty years were out he was, in the opinion of 

 a contemporary and equally able geologist, declared 

 to be certainly wrong on one point. 



Lyell wrote a magnificent work in which he 

 proved, from the point of view of scientific geology, 

 that the whole story of these terrible revolutions 

 was a fiction. There are no such sharp sections in 

 the early history of the earth. Everything goes 

 to show that throughout the whole period of the 

 earth's development the same natural laws have 

 been at work as we find to-day. It is true that the 

 relative positions of sea and land, hill and valley, 

 forest and desert, have often changed ; but very, 

 very slowly, in the course of millions of years. A 

 single drop of water, constantly falling, will hollow 

 out a stone. In these millions of years the water 

 has swept away rocks here, and formed new land 

 by the accumulation of sand there. In these 

 millions of years the sand has been compressed 

 into the gigantic masses that tower above us to-day 

 as sandstone mountains ; they are formed of sand 

 that was originally laid like mud, layer by layer, on 

 the floor of the ocean. 



It was all very plausible ; it seemed to picture 

 an eternal flow of things in which there was no 

 room for Q-od. The changes in the earth's surface 

 were easily brought about without catastrophes, in 

 the course of incalculable ages. God was excluded 

 from geological discussions of the formation of hill 

 and dale. And when it was fully realised, it 



