CONTENTS xvii 



CHAPTEK XXII 



THE PROPERTIES OF VEGETABLE PROTOPLASM 



PAGE 



Adaptability of plants to their surroundings Contractility Ciliary 

 and amoeboid movement Locomotion Movements of rotation 

 and circulation Turgor and its maintenance Mobile condition of 

 protoplasm Rhythm and its manifestations Irritability and its 

 conditions Tone Phototonus Thermotonus Tonic influence 

 of light Etiolation Influence of too brilliant illumination; 

 paraheliotropism, apostrophe and epistrophe Photo-epinasty 

 Regulating action of light on growth Conditions of health 

 Acclimatisation 352-374 



CHAPTER XXIII 



STIMULATION AND ITS RESULTS 



Response of an organism to changes in its surroundings Nature of 

 stimulation Purposeful character of the response Stimulation of 

 light Nyctitropic movements, their conditions and purpose 

 Mechanism of the movements Effect of incidence of lateral light 

 Heliotropism Stimulus of gravitation ; geotropism The Klino- 

 stat Knight's wheel Stimulus of contact Behaviour of various 

 organs in relation to this form of stimulation The root Twining 

 stems and tendrils Hydrotropism Chemical stimuli Chemotaxis 

 Induced rhythm 375-405 



CHAPTER XXIV 



THE NERVOUS MECHANISM OF PLANTS 



The purposeful responses of plants to stimulation ; relation of stimulus 

 to effect Nature of nervous mechanisms Sense organs and their 

 differentiation Motor mechanisms of plants Contraction 

 Regulation of supply of water to the cell Glandular organs Con- 

 duction of impulses ; continuity of protoplasm Co-ordination of 

 impulses Latent period of stimulation After-effects Fatigue 

 Anaesthetics Comparison of nervous mechanisms of plants and 

 animals 406-419 



CHAPTER XXV 



REPRODUCTION 



Distinction between the individual protoplast and the colony or plant 

 Process of multiplication of protoplasts ; gemmation, karyo- 

 kinesis, formation of cell- walla ; free-cell formation Vegetative 



