

TABLE OF CONTENTS 



Introduction 



PAGES 



v-vi 



CHAPTER I 



THE EVOLUTION OF SEX 



1. Reproduction, a Distinctive Feature of Living 



Things 



2. The "Meaning" of Sexual Reproduction 



3. The Body and the Germ-plasm 



4. The Early Isolation of the Germ-cells 



5. The Appearance of the Accessory Organ 



Reproduction 



6. The Secondary Sexual Characters 



7. The Sexual Instincts .... 



s of 



. 1-4 



. 4-1.5 



15-19 



20-23 



23-26 

 26-31 

 31-34 



CHAPTER II 



THE MECHANISM OF SEX-DETERMINATION 



1. The Maturation of the Egg and the Sperm . 35-40 



2. The Cytological Evidence 40-54 



a. Protenor ........ 41-44 



b. Lygseus 44-46 



c. Oncopeltus ........ 46-48 



d. Ascaris . . - 49-52 



e. Aphids and Phylloxerans 52-54 



3. The Experimental Evidence 55-72 



a. The Experiments on Sea-urchins' Eggs . . 55-63 



b. The Evidence from Sex-linked Inheritance . 63-72 



vii 



