X CONTENTS 



CHAP. PAGE 



XVI. ABSORPTION OF CARBONIC ACID . . -193 



Influence ofTemperature, 194 — Influence of Light, 194 

 — Chlorophyll, 194. 



XVII. ASSIMILATION OF CARBON . . .196 



Proteids, 196 — Carbohydrates, 197 — Fats, 197 — Forma- 

 tion of Starch, 198 — Entrance of Carbonic Acid, 199 

 — Green Parts not producing Starch, 200 — Why 

 Light is Essential, 200 — Transport of Carbohydrates, 

 200 — Starch, Sugar, Fats, as Food-substances, 201 — 

 Nutrition of Plants devoid of Chlorophyll, 202. 



XVIII. ABSORPTION OF WATER AND INORGANIC SALTS . 203 

 Absorbing Functions of Roots, 203 — Influence of Exter- 

 nal Conditions, 204 — Essential Chemical Elements 

 and their Absorption, 205. 



ASCENT OF WATER AND SALTS . . . 2o6 



XIX. TRANSPIRATION ..... 209 

 Measurement of Tianspiration, 209 — Leaves as Tran- 

 spiring Organs, 210 — Conditions influencing Tran- 

 spiration, 210 — Function of Transpiration, 211. 



EXCRETION OF LIQUID WATER . . .212 



ROOT-PRESSURE . . . 213 



CAUSE OF ASCENT OF WATER . . .214 



XX. RESPIRATION . . . . -215 



Oxygen essential to Flowering Plants, 217 — Conditions 

 affecting Respiration, 217 — Liberation of Heat during 

 Respiration, 218. 



XXI. GROWTH 



219 



Essential Conditions, 219 — Growth in Length, 220 — 

 Rate of Growth in Length, 220 — Influence of Tem- 

 perature, 220 — Influence of Water-supply, 220 — 

 Influence of Light, 221 — Nutation, 221 — Direction 

 of Growth in Length, 221 — Heliotropism, 221 — 

 Geotropism, 222 — Hydrotropism, 222. 



XXII. IRRITABILITY AND MOVEMENTS OF LIVING PARTS. 224 

 Periodic Movements, 224 — Irritability of Moving 

 Organs, 226. 



APPENDIX ...... 229 



INDEX ....... 239 



