CHAPTEK IV 



THE GENERALISATIONS OF PALEONTOLOGY 



CHARLES Darwin was the first, in his " Origin of 

 Species," to bring forcibly before naturalists the 

 imperfection of the palseontological record. It is 

 now allowed by all that our knowledge of the animals 

 and plants which formerly inhabited the earth is 

 very fragmentary and must always remain so. This 

 is partly because many organisms cannot be pre- 

 served as fossils, either because they had no hard 

 parts and this applies particularly to the lower 

 animals which came first on the stage or because 

 they live on the land or other places where their 

 remains can only be buried under exceptional cir- 

 cumstances. This applies particularly to plants and 

 insects. 



But this is not all, for denudation has destroyed 

 enormous masses of rocks, and the fossils they con- 

 tained have gone with them. We find whole 

 mountain-chains made up of fragmentary rocks 

 which are the proceeds of denudation , and it follows 

 that masses of rock at least equal in size to these 

 mountain-chains must have been destroyed. And, 

 in addition, the greater part of the fossiliferous rocks 



69 



