CONTENTS. 



PAQB. 



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 xerophUy and succu- 

 lence 78 



VIII. Water deficit, or unsatisfied hydration capacity 92 



IX. Temperatiu"e and the hydration and growth of coUoids and of cell-masses. ... 110 



X. Imbibition and growth of Opuntia 128 



XI. The hydration reactions and growth of Mesembryanthemum, Helianthiis, and 



Phaseoliia 145 



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



Literature cited 174 



VI 



