SUBJECT INDEX 



691 



Plant Cells — Continued 



osmotic pressures of, 138-144 



pH of, 79-80 



size, 63 



structure of, 60 

 Plant movements, 653-655 

 Plasmalemma, 1 1 8- 1 1 9 

 Plasmodesms, 61 

 Plasmolysis, 134-136 

 Plasmolytic method of determining 



osmotic pressures, 136-138 

 Plastids, 77-78 

 Plumule, 478, 625, 626 

 Polarity of cells, 623 

 Polarity of molecules, 119-120 



and imbibition, 108 



and permeability of the cytoplasmic 

 membranes, 120- 122 



and solubility, 120 



and surface tension, 26 

 Polypeptides, 438, 443, 447 

 Polysaccharides, 369, 375-379 

 Pore space in soil, 250 

 Potassium, role of, 422-423 

 Potometers, 162-163 

 Precipitation of sols, 48 

 Primary salt absorption, 411 

 Prolamines, 446 

 Promeristem, 551, 553, 554 

 Protamines, 446 

 Proteinases, 444, 466, 471-472 

 Proteins, 437-438 



amphoteric properties of, 53, 465 



as a protoplasmic constituent, 71- 

 72, 437. 554 



classification of, 445-447 



colloidal properties of, 53, 447, 

 465 



storage of, 437, 570 



synthesis of, 443-445 

 Proteoses, 438, 443, 447 

 Protective action in sols, 50 

 Protochlorophyll, 313 

 Protopectinase, 470 

 Protophloem, 557 



Protoplasm, see also cytoplasm and 

 nucleus 



Protoplasm, 



chemical composition, 71-72 

 coagulation of, 74, 594-596 

 streaming of, 75, 502-504, 560 



Protoxylem, 224, 557 



Prunase, 470 



Pulvinus, 654, 667-670 



Pyruvic acid, 543, 544 



Quanta, 306 



Radiant energy, 196, 305-307 

 Radiation, 196-198 

 Radiation, effect of, 



on enzymatic reactions, 476 



on growth, 596-607 



on transpiration, 192 

 Radicle, 625 

 Raffinose, 374, 466 

 Raphe, 625 

 Raw materials, 417 

 Redistribution of mineral elements in 



plants, 415, 423, 424, 498 

 Redistribution of water in plants, 



295-298 

 Reducing action of sugars, 369 

 Reductases, 534-535 

 Reflection of light from leaves, 348 

 Relative humidity, 193-194 

 Reproduction, 



correlation with vegetative devel- 

 opment, 617-619 



effect of carbohydrate and nitrogen 

 metabolism on, 453 



effect of light duration on, 602-607 



periodicity of, 648-649 

 Resins, 399 

 Respiration, 



energy release during, 51 1-5 13 



heat of, 510-513 



relation between aerobic and an- 

 aerobic, 541-543 



relation to growth, 555, 556, 558, 

 630-63 1 



relation to nitrate reduction, 441 

 Respiration, aerobic, 508-513 



comparative rates of, 513-515 



