LIFE IN THE PAST 169 



may, after a while, seem so clear as to receive the 

 acceptance of the scientific mind. Yet the truth re- 

 mains that the early history of the earth, so far as 

 animals and plants are concerned, is probably lost 

 forever. 



The most striking feature concerning the earliest 

 layers of rocks in which good fossils are found abun- 

 dantly is the complexity of the life. With the excep- 

 tion of the backboned anitnals, every important branch 

 of the animal kingdom is represented, and it is just 

 possible that we have even earlier forms of the verte- 

 brates themselves. This, to the evolutionist, is very 

 disconcerting. To find the great groups all well de- 

 veloped at least twenty-five million years ago and to 

 find only fossils built on the same lines since almost 

 nonplusses him. When the geologist tells him what 

 an enormous length of time preceded the rocks in 

 which he finds these fossils and how absolutely these 

 earlier strata have been altered by the later geologi- 

 cal activities he easily understands why it is impos- 

 sible to find fossils in them. As a consequence, the 

 evolutionist is forced to believe that all the earliest 

 animals have left no clear traces behind them. Life 

 as he first surely knows it is already extremely varied 

 and quite well developed in some of its groups. The 

 early animals were as well adapted to the times in 

 which they lived as are the great majority of the ani- 



