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 animals, 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- 
