CONTENTS 



CHAPTER X. 



PAGF. 



Bird Population 294 



CHAPTER XI. 

 Colour, Song and Allied Phenomena 297 



' Nature of colours — Objective colours — Subjective colours — 

 Variety of colours in the same bird — Protective coloration. 

 — Sexual coloration, song, antics, combats — Theories to 

 explain these phenomena — Summary 



CHAPTER XII. 

 Coloration of Eggs 3 21 



CHAPTER XIII. 

 Instinct and Reason ■ . . . 327 



Song — Nest-building— The cuckoo instinct — Piracy — The 

 death-feigning instinct— Origin of instincts. 



CHAPTER XIV. 



Migration 347 



The distances covered— The east and west migration— The 

 return route — Return to the same spot — The time occupied 

 in migration — The beam wind theory— Wings shaped for 

 long flight— From far south to far north— The height at 

 which migrants fly— Order of departure— Partial migrants 

 —The nesting-places of migrants— The cause of migration 

 —How migrants find their way— Exceptional migrations 

 — Stray wanderers— A note on geographical distribution. 



