Crafts et al. — xvi — Water in Plants 



Chapter VI 



WATER AS A PLANT COMPONENT — INTRACELLU- 

 LAR DISTRIBUTION OF WATER: — Introduction — Anatomy 

 OF Cells — Water Content — Binding Forces — Water of Cell 

 Walls — Protoplasmic Water — Water in Vacuoles — ^ Methods 

 FOR Determining Water Partition — Equilibrium Between Phases 



— Summary 59 



Chapter VII 



THE OSMOTIC QUANTITIES OF PLANT CELLS: — A 



Description of the Quantities and of their Interrelations — Mem- 

 branes AND Permeability — Permeability to Solutes — Permeabil- 

 ity TO Water — Permeability of Cell Walls — Osmotic Pressure. 

 Methods of Measuring Osmotic Pressure in Plants. The Plas- 

 molytic Method — Limitations of the Plasmolytic Method — Plas- 

 MOLYTic Method, Experimental Procedure — Further Uses of Plas- 

 molysis — The Plasmometric Method — > Cryoscopy — E;cpression 

 of Sap — The Cryoscope — Physical Principles — Freezing-Point 

 Determination — Vapor Pressure Methods — Osmometric Methods 



— Other Methods for Osmotic Pressure — The Magnitude and 

 Variation of Osmotic Pressure in Plants — Diffusion Pressure 

 Deficit. Methods of Measuring DPD — The Cell Method — Strip 

 OR Simplified Method — The Weight Method — Other Methods 

 FOR DPD — The Magnitude and Fluctuation of DPD Values — 

 Turgor of Plant Cells — Measurement of Turgor — Intercellular 

 Movement of Water — Summary 7Z 



Chapter VIII 



ACTIVE CELL WATER RELATIONS: — Introduction — 

 Evidence from Plasmolytic and Cryoscopic Measurements — Inter- 

 pretation OF Sap Expression Data — Plasmolytic Behavior of Cells 



— Cryoscopy of Tissues and their Equilibrium Bathing Solutions 



— Auxin and Water Uptake — Measurement of Diffusion Pres- 

 sure Deficits — Evidence from Studies of Frost and Drought Re- 

 sistance — Evidence from Animal Physiology — Relation to 

 Solute Accumulation — Relation to Other Plant Functions — 

 Mechanisms — Summary Ill 



Chapter IX 



UPTAKE AND MOVEMENT OF WATER IN PLANTS: — 



Introduction — Water Absorption — Active Absorption — Passive 

 Absorption — Methods of Estimating the Availability of Water — 

 Water Movement — Cohesion Theory — Cohesion and Adhesion — 

 Liquid Continuity in the Xylem — Dye Penetration — Freezing 

 of Stems — Transpiration Experiments — Direct Observation of 

 Xylem — Tensions Developed in the Xylem, Direct Measurements 



— Potometer Experiments — "Suction Tension" Measurements — 

 Newer Metpiods of Estimating Tensions in Xylem — Rate of Water 

 Movement Through Plants — Quantity of Material Moved and 

 Area of Transport — Indicators (Salts — Dyes — Radioactive tracers 



— Heat) — Variations in the Rate of Sap Flow — Water Balance 

 and Redistribution — Translocation of Solutes — Summary . 148 



