XXVI TABLE OF CONTENTS 



CHAPTER IV 



Absorption of Ash-constituexts 



Page 



i. Cultures in artificial media 82 



2. Importance of the essential ash-constituents 84 



3. Importance of the non-essential ash-constituents 85 



4. Ash-analysis of plants 88 



5. Microchemical ash-analysis . 90 



6. The plant and the soil 92 



Summary 102 



CHAPTER V 



Absorption of Materials in General 



r. Materials absorbed by plants 104 



2. Diffusion of gases 104 



3. Absorption of gases 105 



4. Diffusion of dissolved substances 109 



5. Absorption of dissolved substances 119 



Summary 126 



CHAPTER VI 



Movement of Materials in the Plant 



1. General occurrence of movement of materials 130 



2. Movement of gases 130 



3. Movement of water and dissolved substances 133 



4. The transpiration stream 134 



(a) Transpiration 134 



(b) Exudation pressure 140 



(c) Movement of water in the stem I43 



5. Movement of organic substances * 48 



Summary 150 



CHAPTER VII 



Material Transformations in the Plant 



1. The cell as the physiological unit 154 



2. Proteins 155 



3. Enzymes 163 



4. Protein decomposition in plants 170 



5. Nitrogenous products of protein decomposition 175 



6. Protein synthesis in plants. 178 



7. Alkaloids, toxins and antitoxins 181 



8. Lipoids and phosphatides 183 



9. Carbohydrates 185 



to. Glucosides 187 



ci. Organic acids 188 



[2. The importance of water in plants 188 



[3. The germination of seeds 189 



Summary 192 



