10 TABLE OF CONTENTS. 



SECTION III. 



Page 



Consequences of Alternate Generation 167 



CHAPTER TWELFTH. 



METAMORPHOSES OP ANIMALS 174 







" CHAPTER THIRTEENTH. 



GEOGRAPHICAL DISTRIBUTION OF ANIMALS .... 186 



SECTION I. 

 General Laws of Distribution 186 



SECTION II. 



Distribution of the Faunas 194 



I. Arctic Fauna 197 



II. Temperate Faunas 198 



III. Tropical Faunas 204 



SECTION III. 

 Conclusions 207 



CHAPTER FOURTEENTH. 



GEOLOGICAL SUCCESSION OF ANIMALS ; OR, THEIR DISTRIBUTION 



IN TIME 214 



SECTION I. 

 Structure of the Earth's Crust 214 



SECTION II. 



Ages of Nature 221 



Palaeozoic Age 223 



Secondary Age . . . 227 



Tertiary Age 233 



Modern Age 235 



Conclusions 237 



