CONTENTS. 



CHAPTER I 



INTEODTJCTIOX 



General account of the development of animals — Structure of the egg — 

 Maturation or ripening o£ the egg — Fertilisation of the egg — The 

 eady stages of development of the embryo — Theory 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 gUls — The heart and blood- 

 vessels — The urinary and reproductive organs — The skeleton and 

 teeth — Bibliography 90 



CHAPTER IV 



THE CHICK 



G eneral account of the development of the chick — The egg— The early 

 stages of development — The nervous system — The sense organs — The 

 alimentary canal — The heai-t and blood-vessels — The urinary organs 

 — The body cavity and the muscular system — The skeleton — The 

 feathers — Bibliography ... 219 



