xiv CONTENTS 



PAGE 



52. Leaf Structure as a Factor in Transpiration. Stomatal and 

 Cuticular Transpiration 163 



53. The Stomatal Apparatus of the Plant. Methods of Studying 

 Stomatal Movements 165 



54. The Regulation of Transpiration 170 



55. Wilting and Its Physiological Significance 172 



56. The Conservation of Water of Desert Plants. Xerophytes, 

 Mesophytes and Hydrophytes 173 



57. Correlation between Assimilation and Transpiration. Efficiency 



of Transpiration and the Water Requirement 177 



58. Effects of Environment on Structure of Transpiring Organs. 

 Xeromorphism and Drouth Resistance of Plants 178 



CHAPTER VII 



Translocation of Water 181 



59. The Path of Water Translocation 181 



60. The Osmotic Translocation of Water 182 



61. Translocation of Water in the Vessels. Dynamics of the Water 

 Current. The Influence of Transpiration 184 



62. The Rise of Water in the Trunk of a Tree. Water Tension in the 

 Vessels. The Theory of Cohesion 187 



63. Compression of Vessels During the Ascent of Water. The Pres- 

 ence of Air in Vessels 191 



64. The Rate of Water Movement in Plants. Resistance of Wood. 

 Participation of Intermediate Factors in Water Transport 193 



PART III 



UTILIZATION OF RESERVE PRODUCTS 

 AND LIBERATION OF ENERGY 



CHAPTER VIII 



Organic Substances as Plant Food 199 



65. Storage of Substances in Seeds and Other Organs. Their Utiliza- 

 tion in Germination. Major Groups of Reserve Substances 199 



66. Types of Reserve Carbohydrates. Their Products of Hydrolysis. . 202 



67. Enzymatic Splitting of Polysaccharides. Amylase (Diastase) and 

 Cytase. Hydrolysis of Disaccharides and Glucosides 206 



68. General Properties of Enzymes. Methods of Isolation and 

 Purification 209 



