CONTENTS. 



PART I. SOME FACTORS. 

 CHAPTER I. 



PAGE 



The Plant and its Surroundings, - - - i 



CHAPTER n. 



The Plant and its Food, ----- 7 



CHAPTER HI. 

 The Plant a Living Machine, - - - - 15 



CHAPTER IV. 

 Metabolism, -------- 23 



CHAPTER V. 



Roots and Root-Hairs, ----- 35 



CHAPTER VI. 



The Functions of Root-Hairs, - - - - 45 



xi 



