V1U TABLE OF CONTENTS 



UNIT IV. HOW AND WHY DO SEED PLANTS 

 SUCCEED IN LIFE? 



PKOBLEM PAGE 



I. What Are Weeds and What Do They Do? . . . 101 



II. Why and How Should Weeds Be Eradicated? . . . 105 



III. How Are Fruits and Seeds Scattered? .... 108 



PART II 



GREEN PLANTS MAKE THE FOOD OF THE WORLD 



UNIT V. WHY DO SEEDS GERMINATE? 



I. Where Are Baby Plants Found? 116 



II. What Are the Tests for the Organic Nutrients? . . 118 



III. What Factors Are Necessary to Awaken the Embryo 



within the Seed? 120 



IV. What Becomes of the Parts of the Embryo during Its 



Growth into a Young Plant? 122 



V. What Makes a Young Plant Grow? 123 



VI. Where Is the Food Supply of Different Seeds? . .125 

 VII. How Does the Corn Grain Make Use of Stored Food? . 128 



UNIT VI. GREEN PLANTS AS FOOD MAKERS AND 

 FOOD USERS 



I. What Do Plants Take from the Soil? . . . .137 



II. What Factors Influence the Growth of Roots? . . 140 



III. How Does the Structure of a Root Fit It for Its Work? 143 



IV. How Do Root Hairs Take in Water and Soil Salts? . 147 

 V. What Purposes Do Roots Serve? . . . . . 150 



VI. Where Does the Green Plant Manufacture Food? . 151 



VII. What Raw Materials and Conditions Are Needed to 



Make Food? 154 



VIII. What Are the Products and Results in Food Manu- 

 facture? 160 



IX. How Is Food Circulated in the Plant? .... 166 



X. Why Are Plants Modified? 172 



part in 



RELATIONSHIPS AND INTER-RELATIONSHIPS 

 OF LIVING THINGS 



UNIT VII. THE PLANT WORLD AND HOW IT 

 AFFECTS MANKIND 



I. How Do We Classify Plants? 179 



II. What Are Bacteria and Where Are They Found? . .181 



