CONTENTS xi 



CHAPTER XII 



PAGE . 

 THE INNERVATION OP THE FEMALE GBNBKATIVE ORGANS^UTERINE CON- 

 TRACTION — ^PARTUKITION — THE PUERPERAL STATE - 560 



The Innervation of the External Generative Organs — The Innervation 

 of the Ovaries — The Innervation of the Uterus and Vagina and the 

 Mechanism of Uterine Contraction— The Normal Course of Parturi- 

 tion in the Human Female — Parturition in other Mammalia — The 

 Nervous Mechanism of Parturition— Changes in the Maternal 

 Organism — The Cause of Birth — Prolonged Gestation — The 

 Puerperiura. 



CHAPTER XIII 



LACTATION 586 



Structure of the Mammary Glands — The Composition and Properties 

 of Milk — The Influence of Diet and other Factors on the Composition 

 and Yield of Milk — The Duration of Lactation— The Discharge of 

 Milk— The Formation of the Organic Constituents of Milk— The 

 Normal Growth of the Mammary Glands — The Factors which are 

 concerned in the Processes of Mammary Growth and Secretion. 



CHAPTER XIV 



FERTILITY 623 



Effect of Age — Effects of Environment and Nutrition— Effect of Pro- 

 longed Lactation — Influence of the Male Parent — Effect of Drugs 

 — Effects of In-Breeding and Cross-Breeding — Inheritance of Fertility 

 — Certain Causes of Sterility — Artificial Insemination as a Means 

 of overcoming Sterility — Abortion — The Increase of Fertility, a 

 Problem of Practical Breeding — The Birth-rate in Man. 



CHAPTER XV 



THE FACTORS WHICH DETERMINE SEX 661 



(1) Theories which assume tliatSex-determination takes place subsequently 

 to Fertilisation — (2) Theories which assume that Sex-determination 

 takes place at the time of Fertilisation or previously to Fertilisation 

 ' — (3) Theories which limit Sex-determination to no particular period 

 of development, or which assert that Sex may be established at 

 different periods — Hermaphroditism and Sexual Latency — General 

 Conclusions. 



CHAPTER XVI 



PHASES IN THE LIFE OF THE INDIVIDUAL — THE DURATION OF LIFE AND THE 



CAUSE OP DEATH - 701 



Growth of the Body before Birth — Growth of the Body after Birth — 

 Puberty — The Menopause — Senescence— The Duration of Life and 

 the Cause of Death. 



INDEX OP SUBJECTS 729 



INDEX OF AUTHORS i 759 



