TABLE OF CONTENTS. 



PAGE 



PREFACE 7 



CHAPTER I THE SOIL. 



How SOIL is FORMED 9 



WATER TRANSPORTS SOIL 12-13 



EFFECTS OF SOIL EROSION ON THE SURFACE OF 



THE EARTH . . . . . . 14-18 



f>uTiFACE TENSION, EVAPORATION, GRAVITY . . 19-20 



How WATER IN THE SOIL FEEDS PLANTS . . 21-22 



WHEN AND How PLOWING BENEFITS SOIL . . 23 



THE USE OF SOIL AIR . . . . . 26 



WHY CULTIVATION BENEFITS CROPS ... 27 

 SOURCES AND USES OF SOIL HEAT ... 29 

 CHEMICAL COMPOSITION AND KINDS OF SOIL . 34 

 W'ORK OF CRAYFISH, ANTS, RODENTS, ANGLE- 

 WORMS, ETC. 39 



CHAPTER II PLANTS. 



SOIL THE IDEAL HOME FOR PLANTS ... 42 



How PLANTS ARE DISTRIBUTED OVER THE EARTH 43-44 



THE STRUGGLE OF PLANTS FOR EXISTENCE . . 45 



SIMPLE AND COMPLEX PLANTS . . . 47 



ORGANS AND FUNCTIONS OF PLANTS ... 51 



WHY PLANTS HAVE so MANY ROOTS AND LEAVES 53 



SOME INTERESTING FACTS ABOUT LEAVES . . 55-59 



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