CONTENTS 
CHAPTER I. THE ORIGIN OF PLANT AND ANIMAL 
CHILDREN 
I. PLANTS AND LOWER ANIMALS 
PAGE 
Life from Life.1 
Cells.1 
Cell Division.2 
Spores ..3 
Buds and Shoots.4 
Sexual Reproduction. 4 
Spirogyra.4 
Hydra.5 
Sex.6 
Chromosomes.8 
Inheritance.8 
Sibs.10 
Sex Determination.10 
Twins.11 
How Reproducing Cells Get Together . . . .11 
Growth within the Egg. 15 
n. MAMMALS 
The Male Function.17 
The Female Function. 19 
Embryo Life.21 
CHAPTER II. SAFEGUARDING THE SEX LIFE 
Adolescence.24 
Hormones.25 
Castration.26 
vii 
