6c THE DOCTRINE OF DESCENT. 



IV. 



The Animal World in its Historical and Palceontological Development. 



It is SO easy to observe that the earth's crust, from the 

 deepest valleys to the highest mountain top contains 

 innumerable animal remains, that even antiquity could 

 not fail to notice it. But some two thousand years 

 passed by before a correct knowledge was attained of 

 the relations of these remains to the present v/orld. 

 Some thought they were sports of nature, products of 

 creative power leading to no special object, but in a 

 certain measure to be regarded as exercises prelimi- 

 nary to the actual creation of life ; oihers considered 

 the fossils as remains of living creatures, indeed, but 

 of such as still existed, and which had been destroyed 

 by overflows and subsequent withdrawals of the sea. 

 The legend of the universal deluge, especially, derived 

 great support from this second opinion. Only when, 

 at the end of last century, the stratification of the earth's 

 crust was revealed to science, after the outlines of a 

 history of the solar system and of a special history 

 of the earth or geology had been indicated by Kant 

 and Laplace, only then arose the possibility and neces- 

 sity of a real palaeontology, or knowledge of pre- 

 historic life. At the beginning of this century it was 

 discovered that the fossils corresponding with the stra- 



