CONTENTS 



CHAPTER I 



PAGE 



THE CHARACTERS OF LIVING BEINGS . I 



CHAPTER II 



THE METHOD OF DEVELOPMENT ... 21 



CHAPTER III 



THE METHOD OF SCIENCE ..... 30 



CHAPTER IV 



THE LAMARCKIAN DOCTRINE ...... 56 



CHAPTER V 



VARIABILITY ........ 78 



CHAPTER VI 



RETROGRESSION . . . ... . . . IO/ 



CHAPTER VII 



MENDEL'S LAWS ....... 142 



CHAPTER VIII 



THE MUTATION THEORY . . . . . . .169 



CHAPTER IX 



THE FUNCTION OF SEX . . . . . . .187 



CHAPTER X 



SUMMARY ......... 206 



ix 



