CONTENTS. 



PAGE^ 



Preface iii 



Introduction i 



I. ABSORPTION OF LIQUID NUTRIMENT. 



Food of plants 5 



Nutrient elements 3. 



Distilled water as a. nutritive fluid 6 



Influence of iron 6 



Organs of absorption 7 



Zone of root-hairs ........... 9 



Condition of nutrient substances in the soil 11 



Nutrition of parasitic plants 10 



Nutrition of saprophytic plants 11 



Physical aspects of plants 12 



Diffusion 12 



Diffusion through epidermis 14 



Power of selection of food-material 14 



Turgor 16 



II. MOVEMENTS OF WATER IN THE PLANT. 



Root pressure 19 



Transpiration 20 



Evaporation of water fiom leaves 22 



Wilting of excised shoots 23. 



Conditions of transpiration 24 



Cause of wilting 2& 



Guttation . . 27' 



Attraction of soil for water 27 



Uses of transpiration 28' 



Ascent of sap 28' 



Path of sap 33' 



III. ABSORPTION OF GASES. 



Gases used by the plant 35 



Diffusion of gases 36 



Absorption of gases 3& 



