CONTENTS. xi 



BOOK III. 

 PHYSIOLOGY. 



CHAPTER I. 

 Molecular Forces in the Plant. 



PAGE 



Sect. I. The Condition of Aggregation of Organised Structures .... 587 



„ 2. Movement of Water in Plants 598 



„ 3. Movements of Gases in Plants 614 



CHAPTER II. 



Chemical Processes in the Plant. 



Sect. 4. The Elementary Constituents of the Food of Plants 618 



„ 5. Assimilation and Metastasis 626 



„ 6. The Respiration of Plants 644 



CHAPTER III. 



General Conditions of Plant-life. 



Sect. 7. The Influence of Temperature on Vegetation 647 



„ 8. Action of Light on Vegetation 659 



„ 9. Electricity 687 



„ 10. Action of Gravitation on the Processes of Vegetation 690 



CHAPTER IV. 

 The Mechanical Laws of Growth. 



Sect. II. Definition 692 



„ 12. Various Causes of Growth 695 



„ 13. General Properties of the Growing Parts of Plants 697 



„ 14. Causes of the Condition of Tension in Plants 7^8 



„ 15. Phenomena due to the Tension of Tissues in the Growing Parts of Plants . 715 



„ 16. Modification of Growth caused by Pressure and Traction .... 729 



„ 17. Cause of the Growth in Length under constant External Conditions . . 735 

 „ 18. Periodicity of Growth in Length caused by the alternation of Day and 



Night 743 



