SUBJECT INDEX 



687 



Hydration of protoplasm — Continued 

 in relation to photosynthesis, 359, 



361, 362 

 in relation to respiration, 514, 525- 

 526 



Hydration of solutes, effect on osmo- 

 tic pressure, 102-103 



Hydration movements, 655 



Hydrogen equivalent, 14 



Hydrogen ion concentration {see also 

 pH), 14-18 



Hydrolysis, 14 



Hydroponics, 434 



Hydrotropism, 663-664 



Hygrometric paper, 164 



Hygroscopic water in soils, 253 



Hypertonic solutions, 134 



Hypocotyl, 625, 626 



Hyponasty, 654 



Hypotonic solutions, 134 



Hysteresis, 57-58 



Ice formation in plant tissues, 592- 



593 

 Imbibants, 1 07 

 Imbibition, 107-114 

 Imbibition pressure, 114-115 

 Indole-3-acetic acid, 577, 582 

 Indole butyric acid, 582 

 Induction period in photosynthesis, 354 

 Infrared, 306 



effect on growth, 600, 60 1 

 Inhibitors, enzymatic, 476 

 Initial cells, 553 

 Injury, effect of, 



on permeability, 126 



on respiration, 526 

 Intake of water, see absorption of 



water 

 Interface, 27 

 Interfacial tension, 26-27 

 Intermicellar spaces, 66-67 

 Intercellular spaces, 157-158, 195, 

 198-200, 206-208, 270, 554, 



556, 563, 592-593 

 Internal "competition" for water, 

 295-298 



Internal surface of leaves, effect of, 



on photosynthesis, 320 



on transpiration, 203 

 Internode, 562 

 Intussusception, 556 

 Inulase, 378, 469 

 Inulin, 378 

 Invertase, see sucrase 

 Ions, 12 



accumulation by plant cells, 407- 

 411 

 Iron, role of, 314, 423-424, 554 

 Isoelectric point, 



of cytoplasm, 74-75 



of gelatin, 53, 114 



of sols, 48 

 Isomerism of sugars, 370-371 

 Isotonic solutions, 134 



Laccases, 534 



Lammas-shoots, 646-647 



Latex, 37 



Law of the minimum, 338, 588-589 



Leaf gap, 559 



Leaf mosaics, 655 



Leaf primordia, 562 



Leaves, 



anatomy of, 157-158, 361 



autumnal coloration of, 385-386 



daily variations in water content 

 of, 289-291 



development of, 562 



optical properties of, 348, 349 



temperature of, 195 

 Lecithins, 395, 399, 421, 422 

 Lecithoproteins, 447 

 Lenticular transpiration, 156 

 Leucoplasts, 78, 323, 378 

 Light, 305-307 

 Light, effect of, 



on anthocyanin synthesis, 384 



on chlorophyll synthesis, 312-313 



on germination, 631 



on permeability, 125-126 



on respiration, 526 



on stomatal opening, 184-186, 209 



on transpiration, 192, 209 



