CONTENTS 



CHAPTER I 



PAGE 



Introduction ...... i 



CHAPTER n 



The Scientific Study of Variation and Heredity . 14. 



CHAPTER HI 



Inheritance and Variation in Mankind . . -35 



CHAPTER IV 



The Inheritance of Mental Defect . . .61 



CHAPTER V 



The Inheritance of Ability . . . -73 



CHAPTER VI 



The Rise of Families . . . . ,92 



CHAPTER VII 



The Decline of Families . . . . .109 



vii 



