CONTENTS. XI 



BOOK IL— ANALYSIS OF SEX— ORGANS, TISSUES, 



CELLS. 



CHAPTER V. 



PAGE 



Sexual Organs and Tissues ----- 57-64 



§ I. Essential sexual organs of animals. 



§ 2. Associated ducts, 



§ 3. Origin of yolk-glands, &c. 



§ 4. Organs auxiliary to inapregnation. 



§ 5. Egg-laying organs. 



§ 6. Brood-pouches. 



CHAPTER VI. 



Hermaphroditism . - . . . - 65-80 



§1. Definition of hermaphroditism ; its varied forms. 

 § 2. Embryonic hermaphroditism. Ploss, Laulanie, Sutton. 

 § 3. Casual or abnormal hermaphroditism, from jelly-fish to 



mammal. 

 § 4. Partial hermaphroditism, from butterflies to birds. 

 § 5. Normal adult hermaphroditism, from sponges to toads. 

 § 6. Degrees of normal hermaphroditism. 

 § 7. Self-fertilisation and its preventives. 

 § 8. Complemental males — cirripedes and Myzostomata. 

 § 9. Conditions of hermaphroditism ; its association with 



passivity and parasitism. 

 § 10. Origin of hermaphroditism ; the primitive condition ; 



persistence and reversion. 



CHAPTER VH. 



The Sex-Elements (General and Historical) - - 81-96 



§ I. The ovum-theory. 



§ 2. The history of embryology, "evolution "and " epigenesis. " 

 Harvey's epigenesis and prevision of ovum- 

 theory. 

 Malpighi and early observers. 

 Preformation school; "evolution" according to 

 Haller, Bonnet, and Buffon ; ovists and ani- 

 malculists. 

 Wolffs demonstration of epigenesis. 

 Wolff's successors. 

 § 3. The cell-theory. 

 § 4. The protoplasmic movement. 

 § 5. Protozoa contrasted with Metazoa ; the making of the 



" body." 

 § 6. General origin of the sex-cells in sponges. 



,, ,, ,, ,, coelenterates. 



,, ,, ,, ,, other Metazoa. 



§ 7. Early separation of the sex-cells in a minority of cases. 



