692 



SUBJECT INDEX 



Respiration, aerobic — Continued 



factors affecting, 521-527 



mechanism of, 544-547 



methods of measuring, 513 



relation to accumulation of ions, 

 408-409, 410 

 Respiration, anaerobic, 519, 538-540 



injurious effects of, 541 



mechanism of, 543-544 



relation to alcoholic fermentation, 



540-541 . 

 Respiratory pigments, 545-546 



Respiratory ratio, 517-521 



Rest period, see dormancy 



Rhizocaline, 583 



Ribose, 371-372 



Ringing, 486. 489-490, 494-496, 504 



Root cap, 268, 269, 478 



Root hairs, 271, 273-274 



Root formation, effect of auxins on, 

 581-582 



"Root pressure," 231-233, 278-280 



Roots, 



absorbing region of, 268 

 anatomy of, 269-273 

 depth of penetration, 266-267 

 external features, 265-266 

 growth of, 269-273, 276-277, 558- 



559 



lateral extent, 267-268 

 Roots, lateral, origin of, 272-273 

 Root systems, 265-268 



relation to transpiration, 204 

 Root tip, 268 



Salicin^ 381 



Salting out, 52-53, 593 



Salts, 14 



Sand cultures, 432-434 



Saponification, 397 



Sapwood, 223-224, 236 



Scutellum, 478 



Seeds, 



dormancy of, 626, 631-634 



germination of, 626-631 



longevity of, 636-637 



structure of, 625-626 



Senescence, 514, 541, 568, 648 



Shoot-root ratio, 609, 619-621 



Sieve plate, 482, 483 



Sieve theory of permeability, 128 



Sieve tubes, 482-484, 485 



Silicon, role of, 425-426 



Sinigrin, 381-420 



Soaps, 396-397 



Sodium, role of, 425 



Sodium acetate, 18 



Soil atmosphere, 250 



Soil, constitution of, 246-251 



Soil colloids, 247, 249, 403-406 



Soil organisms, 250-251, 454-457 



Soil respiration, 341-342, 346-347 



Soil solution, 249-250, 403 



Soil solution, concentration of, effect 



on absorption of water, 283 

 Soil water relations, 251-255 

 Solarization, 354 

 Solar radiation, 306-307 

 Solation, 55-56 

 Sols, 39-54 

 Solubility of gases, 8 

 Solubility theories of permeability, 



128-130 

 Solution cultures, 418-419, 427- 



434 

 Solutions, 7-1 1, 14 

 Solution volume, lO-il 

 Stachyose, 374-375 

 "Standard day," 187-188, 204, 292, 



293, 362, 643 

 Starch, 376 

 Starch grains, 377-378 

 Starch-sugar equilibrium, 386-388 

 Starch synthesis, 323-324 

 Statolith theory, 662 

 Stems, 



anatomy of, 217-229, 481-486 



growth of, 551-558 

 Sterols, 396 

 Stomata, see stomates 

 Stomatal transpiration, 156 

 Stomatal opening, 



daily periodicity, 1 87-1 90 



factors affecting, 184-187, 209 



