TABLE OF CONTENTS 



PAGES 



INTRODUCTION xix-xxii 



PART I 



THE THEORY OF ORGANIC EVOLUTION 3-83 



Natural Selection 3-47 



Heredity 3-10 



Variation 7-10 



The Struggle for Existence 10-18 



Mutation 18-20 



General Principles in the Operation of Natural Selection . . 20-28 



Artificial Selection 28-31 



Objections to Natural Selection as a Factor in Evolution . . 31-47 



Sexual Selection 47-60 



Objections to the Theory of Sexual Selection .... 56-60 



Segregation ........... 60-67 



The Inheritance of Parental Modifications 67-82 



Summary of Part I 82-83 



PART II 



THE PHENOMENA EXPLAINED BY THE THEORY 87-163 



Comparative Anatomy 88-96 



Classification 88-92 



Homology 92-93 



Vestigial Structures ..... ... 93-96 



Embryology ........... 96-103 



Paleontology 103-111 



Geographical Distribution 111-116 



Color in Animals 116-151 



Protective Coloration and Resemblances ..... 117-125 



Aggressive Coloration and Resemblances 125-127 



xi 



