Her beauty fed my common earth.

—John Masefield.

PART II
The Development of the Baby

CHAPTER III. DEVELOPMENT OF THE OVUM, EMBRYO, FETUS, PLACENTA, CORD AND MEMBRANES. The Ovum. The Spermatozoon. Fertilization. Heredity. Sex-determination. Most Favorable Age for Motherhood. The Morula. Growth in the Uterus. The Decidua. Ectoderm. Mesoderm. Entoderm. The Chorion and Placenta. The Amnion. The Umbilical Cord. The Fetus. Growth by Months. Factors Influencing the Size of Child. Multiple Pregnancy. Extra-uterine Pregnancy.

CHAPTER IV. GROWTH AND PHYSIOLOGY OF THE FETUS. Circulation. Kidneys. Bowels. Head. Fontanelles. Occipital Measurements.

CHAPTER V. SIGNS, SYMPTOMS, AND PHYSIOLOGY OF PREGNANCY. Duration of Pregnancy. Date of Labor. Signs of Pregnancy: Presumptive, Probable, and Positive. Physiological Changes in the Maternal Organism: Uterus. Cervix. Vagina. Tubes and Ovaries. Abdomen. Umbilicus. Breasts. Cardio-Vascular System. Respiratory Organs. Digestive Tract. Urinary Apparatus. Bony Structures. Skin. Carriage. Temperature. Mental and Emotional Changes. Ductless Glands.

CHAPTER III
THE DEVELOPMENT OF THE OVUM, EMBRYO, FETUS, PLACENTA, CORD AND MEMBRANES

As we learned in the last chapter, some of the ova which are discharged into the peritoneal cavity enter the fimbriated end of the tube, while very many others perish. As a rule an ovum enters the tubal opening adjacent to the ovary from which it has been discharged, but it is possible for this tiny cell to travel across the body and enter the tube on the opposite side.

This migration of the ovum, as it is termed, has been demonstrated in cases in which pregnancy has followed removal of the ovary on one side and the tube on the other.