CONTENTS 



PART I. THE WORLD IN WHICH WE LIVE 



CHAPTER PAGE 



I. Introduction 3 



II. What goes on in the World 7 



III. Fire 11 



PART II. LIFE PROCESSES OF THE ORGANISM 



IV. Living Things and Non-living Things 15 



V. The Living Stuff 20 



VI. The Conditions of Life 25 



VII. Air and Soil in Relation to Sprouting .... 29 



VIII. Seeds and Seedlings 32 



IX. External Forces and Plants 37 



X. Absorption from the Environment 40 



XI. Roots of Plants 42 



XII. What Food Is 50 



XIII. The Origin of Food 53 



XIV. The Chemical Cycle of Life 57 



XV. The Soil as the Source of our Materials ... 65 



XVI. The Leaf as Starch Factory 70 



XVII. Our Dependence upon Leaves and Chlorophyl . 73 



XVIII. Starch-Making and Digestion 78 



XIX. Digestive System in Man 81 



XX. Health and Food Standards 89 



XXI. Food Requirements 94 



XXII. Food and Dietaries 105 



XXIII. Food Habits 114 



XXIV. The Social Side of the Food Problem 122 



vii 



\')V1 



