behind. To-day there are hundreds of thousands of species of small soft-bodied creatures in our world which it is inconceivable can ever leave any mark for future geologists to discover. In the world’s past, millions of millions of species of such creatures may have lived and multiplied and flourished and passed away without a trace remaining. The waters of the warm and shallow lakes and seas of the so-called Azoic period
Table of Contents
III THE BEGINNINGS OF LIFE
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