CONTENTS 



CHA I'. PACK 



I THE STUDY OF SEX .... 7 



II THE EVOLUTION OF SEX ... 20 



III SEX-CHARACTERS ILLUSTRATED . . 56 



IV THEORY OF SEX DIMORPHISM . , 72 

 V WHAT DETERMINES SEX? ... 98 



VI THE CYCLE OF SEX . . . .117 



VII CORRUPTIO OPTIMI PESSIMA . .142 



VIII PROS AND CONS OF SEX-EDUCATION . 157 



IX THE ETHICS OF SEX . . . .181 



X SEX AND SOCIETY .... 203 



BIBLIOGRAPHY . . . 245 



