CONTENTS. xix 



PAGE 



941. The Formation of the Spermatozoa 366 



942. The Movements of the Spermatozoa 368 



943. The Chemical Constituents of Semen 369 



944. The Lymphatics of the Testis 369 



Accessory Organs. 



945. The Vesiculse Seminales and Prostate 369 



946. Erectile Tissue 370 



947. The Nature of Erection 371 



948. The Emission of Semen 373 



CHAPTER II. 

 PREGNANCY AND BIRTH. 



SECTION I. 

 THE PLACENTA. 



949. The Spermatozoon enters and unites with the Ovum 374 



950. The Formation of the Decidua 374 



951. The Decidua Serotina is transformed into the Placenta .... 376 



952. The Structure of the Placenta 377 



953. The Nature of the Vascular Events taking place in the Placenta . 378 



954. The Shedding of the Placenta 379 



SECTION II. 

 THE NUTRITION OF THE EMBRYO. 



955. The Embryo breathes by and feeds upon the Maternal Blood of the 



Placenta 382 



956. The Blood and Blood-Flow in the Umbilical Arteries and Umbilical 



Vein 383 



957. The Amniotic Fluid, its Nature and Origin, its Relations to the 



Nutrition of the Foetus 385 



958. The Transmission of Food Material from the Mother to the Foetus 386 



959. Glycogen in the Foetus 388 



960. The Movements of the Foetus 388 



961. The Digestive Functions of the Foetus 389 



962. The Foetal Circulation towards the Close of Uterine Life ... 390 



963. The Cause of the First Breath 392 



964. The Changes in the Circulation taking place at Birth .... 393 



