CONTENTS. 



PREFACE iii 



INTRODUCTION . . ... . . . . - . . .1 



I. ABSORPTION OF LIQUID NUTRIMENT. 



Food of plants . . . . . . . . . % . . $ 



Nutrient elements .3 



Distilled water as a nutritive fluid . . -< .5 

 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 *. IO 



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 from 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 . . . . . . . . .23 



Ascent of sap .23 



Path of sap . . . . . .33 



III. ABSORPTION OF GASES. 



Gases used by the plant . .35 



Diffusion of gases ........... 36 



Absorption of gases . . .- . .36 



