CONTENTS xv 



PAGE 



temperature Influence of the light rays on temperature ; impor- 

 tance of anthocyan Absorption of heat by conduction Dissipa- 

 tion of heat in evaporation of water Kadiation Nyctitropic 

 movements Loss and gain of heat by conduction Eegulation of 

 heat Power of resistance to extremes of temperature . . 320-329 



CHAPTEK XXII 



INFLUENCE OF THE ENVIRONMENT ON PLANTS 



Characters of aquatic plants ; influence of a watery environment on 

 structure Xerophytes and their peculiarities Alpine plants- 

 Epiphytes Parasites Insectivorous plants .... 330-344 



CHAPTEK XXIII 



THE PROPERTIES OF VEGETABLE PROTOPLASM 



Adaptability of plants to their surroundings Contractility Ciliary 

 and amoaboid movement Locomotion Movements of rotation 

 and circulation Turgor and its maintenance Mobile condition of 

 protoplasm Ehythm and its manifestations Irritability and its 

 conditions Tone Phototonus Thermotonus Tonic influence of 

 light Etiolation Influence of too brilliant illumination ; para- 

 heliotropism, apostrophe and epistrophe Photoepinasty Regu- 

 lating action of light on growth Conditions of health Acclima- 

 tisation . 345-36 



CHAPTEK XXIV 



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 . . . 368-396 



