CONTENTS. 



PAGE. 



1. Growth and colloidal reactions 1 



II. Fundamental features of phytocoUoids 11 



III. The constituents of biocoUoids which affect hydration and growth 27 



IV. The effect of salts and acids on biocoUoids and cell-masses 37 



v. The effects of organic acids and their amino compounds on hydration and 



growth 54 



VI. Reactions of biocoUoids and ceU-masses to culture solutions, bog, swamp, and 



ground water, and other solutions 65 



Vll. Fluctuating or alternating hydration effects. Basis of xerophily and succu- 

 lence 78 



VIII. Water deficit, or unsatisfied hydration capacity 92 



IX. Temperature and the hydration and growth of coUoids and of ceU-masses .... 110 



X. Imbibition and growth of OpUntia 128 



XI. The hydration reactions and growth of Mesevibryanthemum, Helianthus, and 



Phaseolus 145 



XII. Water-content, dry weight, and other general considerations 161 



Literature cited 174 



VI 



