CONTENTS. 



PAGE- 



INTRODUCTION 1 



MANUALS AND TEXT-BOOKS 4 



PART FIRST. 



CHAPTER I. 



DESCRIPTION OF THE SEXUAL PRODUCTS 7 



THE EGG-CELL T 



THE SEMINAL FILAMENTS 19 



Historical 23 



SUMMARY . 27 



CHAPTER II. 

 THE PHENOMENA OF THE MATURATION OF THE EGG AND THE 



PROCESS OF FERTILISATION .SO 



THE PHENOMENA OF MATURATION 30 



Historical 35 



THE PROCESS OF FERTILISATION -37 



Historical 45 



SUMMARY 46- 



CHAPTER III. 



THE PROCESS OF CLEAVAGE 51 



Historical 69 



SUMMARY 72 



CHAPTER IV. 

 GENERAL DISCUSSION OF THE PRINCIPLES OF DEVELOPMENT 76 



CHAPTER V. 



THE DEVELOPMENT OF THE TWO PRIMARY GERM-LAYERS 



(CASTRO A-THEORY) 84 



CHAPTER VI. 

 THE DEVELOPMENT OF THE TWO MIDDLE GERM -LAYERS 



(CCELOM-THEORY) 106 



SUMMARY 142 



CHAPTER VII. 

 HISTORY OF THE GERM-LAYER THEORY 145 



CHAPTER VIII. 



DEVELOPMENT OF THE PRIMITIVE SEGMENTS . . . .161 

 SUMMARY . 1G9- 



