X TABLE OF CONTENTS. 



CHAPTER IX. 



PAGE 



How PLANTS OBTAIN THEIR FOOD, 1 81 



1. Sources of Plant Food 81 



2. Parasites and Saprophytes 83 



3. How Fungi Obtain their Food 86 



4. Mycorhiza 91 



5. Nitrogen-gatherers 92 



6. Lichens 93 



CHAPTER X. 



How PLANTS OBTAIN THEIR FOOD, II 97 



Seedlings, 97. Digestion, 107. Assimilation 109 



CHAPTER XI. 

 RESPIRATION no 



CHAPTER XII. 

 GROWTH 118 



CHAPTER XIII. 

 IRRITABILITY 125 



PART II. MORPHOLOGY AND LIFE HISTORY 

 OF REPRESENTATIVE PLANTS. 



CHAPTER XIV. 

 SPIROGYRA. 136 



CHAPTER XV. 

 VAUCHERIA. 142 



CHAPTER XVI. 

 (EDOGONTOM. .' I4 7 



CHAPTER XVH. 



COLEOCBUETE. 153 



CHAPTER XVIII. 

 CLASSIFICATION AND ADDITIONAL STUDIES OF THE ALG^ 158 



CHAPTER XIX. 

 FUNGI : MUOOR AND SAPROLEGNIA 1 



