CONTENTS. 



CHAPTER I 



INTRODUCTION 



PAGE 



General account of the development of animals Structure of the egg 

 Maturation or ripening ot the egg- Fertilisation of the egg The 

 early stages of development of the embryo Theoiy of fertilisation 

 Segmentation of the egg The germinal layers The general history 

 of development The recapitulation theory The origin of sex 

 Bibliography 1 



CHAPTER II 



AMPHIOXUS 



Structure of the adult Amphioxus Morphological importance of Am- 

 phioxus General account of the development of Amphioxus The 

 early embryonic development The condition at the time of hatching 

 The later embryonic development The condition at the close of the 

 embryonic period The larval period The adolescent period 

 Bibliography 37 



CHAPTER III 



THE FROG 



General account of the development of the frog The egg The early 

 stages of development The nervous system The sense organs The 

 alimentary canal The gill-clefts and the gills The heart and blood- 

 vessels The urinary and reproductive organs The skeleton and 

 teeth Bibliography 90 



CHAPTER IV 



THE CHICK 



General account of the development of the chick The egg The early 

 stages of development The nervous system The sense organs The 

 alimentary canal The heart and blood-vessels The urinary organs 

 The body cavity and the muscular system The skeleton The 

 feathers Bibliography 219 



