CONTENTS 



Page 

 PREFACE ix 



LIST OF PLATES xvii 



LIST OF TEXT FIGURES Xviii 



CHAPTER I. THE PLACE OF THE HIGHER ANIMALS, 

 AND OF MANKIND IN PARTICULAR, IN THE GENERAL 

 SCHEME OF ANIMAL REPRODUCTION 8 



Simple division into parts a frequent mode of repro- 

 duction in lower animals; necessity of egg and sperm 

 cells in higher and more complicated creatures ; the par- 

 ticipation of two individuals, male and female, essential 

 to the process in all higher animals ; in mammals, includ- 

 ing mankind, the fertilized egg sheltered and nourished 

 within the mother's body; correlation of the various 

 organs of the reproductive system to this end by action 

 of chemical substances (hormones) made in the sex 

 glands. 



CHAPTER II. THE HUMAN EGG AND THE ORGANS THAT 

 MAKE AND CARE FOR IT 



The egg a cell growing in a cavity (follicle) in the 

 ovary; its progress, after discharge from the ovary, via 

 the oviduct to the uterus ; its implantation in the uterus, 

 if fertilized by a sperm cell ; division into many cells and 

 development into an embryo ; nourishment from the moth- 

 er's blood during growth in the uterus, through an organ 

 of attachment, the placenta. 



{ adii } 



33 



