CONTENTS xi 



PAGE 



Changes in Movements New Ways of Look- 

 ing after the Young New Kinds of Protec- 

 tion Betwixt-and-Between Animals Haunts 

 within Haunts Beneath the Ground Cave 

 Animals Arboreal Life 185 



CHAPTER VI 

 THE MASTERY OF THE AIR 



What Getting into the Air meant The Flight of 

 Insects Why are there so many Insects? 

 The Flying Dragons The Flight of Birds 

 Different Kinds of Flying in Birds Migration 

 the Climax The Fourth Solution of Flight 

 Fitnesses of Birds and Bats Attempts at 

 Flight Gossamer Spiders . . . .231 



Index 270 



