TABLE OF CONTENTS 



Introduction 



PAGES 



v-vi 



chapter i 

 thp: 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 



. 4-15 



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 



2. The Cytological Evidence 



a. Protenor 



b. Lygseus 

 f. Oncopeltus . 



d. Ascaris 



e. Aphids and Fhylloxerans 



3. The Experimental Evidence 



a. The Experiments on Sea-urchins' Eggs 

 h. The Evidence from Sex-linked Inheritance 



vii 



35-40 



40-54 



41-44 

 44-46 

 46-48 

 49-52 

 52-54 



55-72 



55-63 

 63-72 



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