CONTENTS. 



PAGE 



PREFACE iii 



INTRODUCTION i 



I. ABSORPTION OF LIQUID NUTRIMENT. 



Food of plants ............ 3 



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 II 



Nutrition of parasitic plants . . . . . . . . .10 



Nutrition of saprophytic plants ......... n 



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 ............ ig> 



Transpiration ............ 20 



Evaporation of water fiom leaves . 22 



Wilting of excised shoots .......... 23 



Conditions of transpiration ......... 24 



Cause of wilting ............ 26 



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 ........... 36 



v 



