CONTENTS 



I 



PAGE 



The Chain of Life Traced Backward in Geological 



Time 3 



II 

 Life in the Early Cambrian . ..... 17 



III 



Pre-Cambrian Life ...••••• 47 



IV 



Foundations of the Continents, and their General 



Testimony as to Life 79 



V 



Probabilities as to Laurentian Life, and Conditions 

 OF its Preservation 107 



VI 



The History of a Discovery 125 



VII 



The Dawn of Life 147 



