xvi CONTENTS 



PAGE 



87. Periodicity of Growth. The Rest Period. Methods of Forcing 

 Plants 288 



88. Seed Germination 293 



89. Influence of Temperature on Growth. Thermophilous Organisms. 297 



90. Effects of Light on Growth. The Daily Periodicity of Growth. 

 Formative Action of Light 302 



91. Influence of Moisture on Growth of Plants 305 



92. Effects of Chemical Stimulants on Growth 307 



CHAPTER XI 



The Movements and Sensitivity of Plants 312 



93. Plant Movements and Their Mechanism. Sensitivity 312 



94. Phototropism 314 



95. Geotropism 322 



96. Chemo-, Hydro-, and Thermotropism 329 



97. Movements of Twining and Climbing Plants 333 



98. Nyctinastic and Seismonastic Movements 336 



CHAPTER XII 



Reproduction 342 



99. The Normal Life Cycle of Higher Plants. Annual and Perennial 

 Plants '. 342 



100. Effects of Environment on Time of Fruiting. Photoperiodism.. . 345 



101. The Internal Factors of Fruiting 351 



102. Physiological Processes Accompanying Fertilization and Embryo 

 Development 352 



103. The Role and Methods of Plant Propagation 356 



104. Propagation by Cuttings and Layers. Regeneration and 

 Polarity 358 



105. Budding and Grafting. Chimeras 362 



Reference Books and Periodicals on Plant Physiology 367 



Index 371 



