CONTENTS. 



PAGE 



Essential Conditions of Life 5 



Influence of Climate on the Distribution of Life . .11 

 Influence of Depth on the Distribution of Life jn the Sea . 15 



Provinces of Life 18 



Types of Life Structure 25 



Adaptations of Life Structure 31 



System of Life Coeval with Man 45 



^Successive Systems of Life ....... 53 



^Variety of the Forms of Life in Successive Periods . . 59 



Origin of Life on the Earth 67 



} Earliest Systems of Life 70 



- ^Successive Systems of Marine Invertebral Life ... 81 

 Changes of Marine Animals with Elapsed Time , . .84 



Freshwater Life . . 109 



Terrestrial Life 115 



Antiquity of the Earth 119 



Changes of Climate 142 



Physical Aspects of the Earth 165 



THEORIES AND OPINIONS. 



Formed Stones 175 



Cataclysms 178 



All Life derived from the Sea . 180 



