IV TABLE OF CONTENTS. 



SECTION III. 

 Consequences of Alternate Generation 136 



CHAPTER TWELFTH. 



METAMORPHOSES OF ANIMALS 142 



CHAPTER THIRTEENTH. 



GEOGRAPHICAL DISTRIBUTION OF ANIMALS . . . 154 



SECTION I. 



General Laws of Distribiition .... . 154 



SECTION II. 



Distribution of the Faunas 161 



I. Arctic Fauna 164 



n. Temperate Faunas 166 



III. Tropical Faunas 172 



SECTION III. 

 Conclusions 175 



CHAPTER FOURTEENTH. 



GEOLOGICAL SUCCESSION OF ANIMALS ; OR THEIR DISTRIBUTION IN TIME 182 



SECTION I. 

 Structure of tlie Earth's Crust ....'.. 182 



SECTION II. 



Ages of Nature 189 



Paleozoic Age 191 



Secondary Age 195 



Tertiary Age 201 



Modern Age ... 203 



Conclusions 205 



