10 TABLE OF CONTENTS. 



SECTION III. 



Pigt 



Coiiscquencej of Alternate Generation .... , 167 



CHAPTER TWELFTH. 

 Metamorphoses of Animals 174 



CHAPTER THIRTEENTH. 



Geographical Distribution of Animals .... 186 



SECTION I. 

 General Laws of Distribution 186 



SECTION II. 



Distrihidion of the Faunas 194 



I. Arctic Fauna 197 



II. Temperate Faunas 198 



III. Tropical Faunas 204 



SECTION III. 

 Conclusions 207 



CHAPTER FOURTEENTH. 



Geolcgical Succession of Animals ; or, their Distribution 



IN Time 214 



SECTION I. 

 Structure of the Eartlt's Crust 214 



SECTION II. 



Ages of Nature 221 



Palaeozoic Age 223 



Secondary Age 22? 



Tertiary Age 233 



Modern Age 2'Mi 



Conclusions 237 



