CONTENTS 



PART I. GETTING ACQUAINTED WITH LIFE 



CHAPTER PAGE 



I. What is Biology ? 3 



II. What Kinds of Things are Living ? 13 



III. Some Life Relationships: Butterflies and Bees . 26 



IV. The Cycle of Life : Flowers 41 



V. Living Matter 56 



VI. Living Conditions ; the Seed 64 



VII. The Sorting of Plants and Animals 72 



VIII. Mother Earth 91 



PART II. THE BIOLOGY OF HEALTH 



INTERMEZZO. WHAT EVERYBODY WANTS 



KEEPING THE BODY IN CONDITION 



IX. The Meaning of Food loi 



X. Where Food Comes From 107 



XL How Food is Taken In 126 



XII. Working over the Body's Income 131 



XIII. What to Eat 139 



XIV. Hygiene of Food and Feeding 152 



XV. The Air ... 160 



XVI. Hygiene of Respiration and Ventilation . . . 168 



XVII. Distribution of Material within the Body . . 176 



XVIII. Hygiene of the Blood and the Circulation . . 187 



XIX. Elimination of Wastes 193 



XX. The Skin and the Appendages 198 



XXI. The Unity of Life 208 



vii 



