xlii 



CONTENTS. 



§ 690. Erectile tissue ... 1115 



§61)1. The nature of erection 1116 



§ 692. The emission of semen 1117 



CHAPTER II. 

 Pregnancy and Birth. 



SECTION I. 



The Placenta. 



§ 693. The spermatozoon enters and unites with the ovum . . . 1119 



§ 694. The formation of the decidua 1119 



§ 695. The decidua serotina is transformed into the placenta. The shed- 

 ding of the placenta 1120 



SECTION II. 



The Nutrition of the Embryo. 



§ 696. The embryo breathes by and feeds upon the maternal blood of the 



placenta 1123 



§ 697. The blood and blood- flow in the umbilical arteries and umbilical 



vein 1124 



§ 698. The amniotic fluid, its nature and origin, its relations to the nutri- 

 tion of the foetus 1126 



§ 699. The transmission of food material from the mother to the foetus . 1128 



§ 700. Glycogen in the foetus 1129 



§701. The movements of the foetus . • 1130 



§ 702. The digestive functions of the foetus 1130 



§703. The foetal circulation towards the close of uterine life . . . 1132 



§ 704. The cause of the first breath 1134 



§ 705. The changes in the circulation taking place at birth . . . 1134 



SECTION III. 



Parturition. 



§ 706. The period of gestation .... 



§707. The events of "labour" .... 



§ 708. The reflex nature of parturition 



§ 709. The nerves concerned in the act 



§ 710. The causes determining the onset of labour 



§ 711. The inhibition of parturition . 



1136 

 1137 

 1140 

 1141 



11-12 

 1142 



