552 



INDEX 



Roots, primary, 6*, 12*, 16*, 19 

 Roots, propagation by, 436 

 Roots, secondary, 6*, 12*, 19, 32* 

 Roots, selective action in, 36 

 Roots, storage of nourishment in, 



23*, 25, 26* 



Roots, structure of, 24, 25 

 Roots, tertiary, 19 

 Roots, water, 20 

 Rootstock, 51*, 52*, 53 

 Rosette plants, 50*, 51 

 Rotation of protoplasm, 202 

 Rots, 246*, 253, 254 

 Russian thistle, 440*, 447, 448 

 Russian thistle, spread of, 451, 452 

 Rusts, 260-264* 

 Rye grass, Plate I 



Saccharomycetes, 238*, 239 



Sac fungi, 248-257* 



Sac fungi, summary of, 257 



Sagebrush, 480, 493, 494 



Sage, pollination in flowers of, 430*, 



431* 



Sagittaria, leaf of, 461* 

 Sago palm, 78 

 Sahara, 482* 

 Salicornia, 483*, 493 

 Salt marsh plants. See Halophytes 

 Salt marshes, 458 

 Salts, 29 



Salver-shaped, App. II 

 Salvinia, 320* 



Sap, descent of, 74*, 75*, 77 

 Sap, rise of, 29*, 30, 74*, 75*, 77 

 Saprolegnia, 244* 

 Saprolegniales, 242-244* 

 Saprophytes, 172, 227, 409 

 Sapwood, 72 

 Sargassum, 212*, 213 

 Scale, 16, 18 

 Scalloped, App. I 

 Scaly buds, 81 

 Schizocarp, 147* 

 Schizomycetes, 228-237* 

 Scion, 68 



Scirpus, cross section of stem of, 58* 

 Sclerenchyma, 58*, 59 

 Scotch pine (Pinus sylvestris), 366*, 



368*, 370* 

 Scouring rush, 325 

 Sea lettuces, 187* 

 Seasonal plants, 459, 467 

 Secondary growth, 65-67* 

 Secondary root, 6*, 12*, 19 



Secondary roots, direction of, 32* 



Sections, leaf, 102, 103*, 466* 



Sections, root, 24*, 25* 



Sections, wood, 59-68* 



Sedge, rootstock of, 51* 



Seed, 5-12*, 355, 356 



Seed coats, 6, 13 



Seed dispersal, 438-446* 



Seed habit, origin of, 389-393 



Seed leaf, 5-14*, 18* 



Seedlings, 6*, 8*, 9-18*, 22 



Seedlings, mutilated growth of, 8* 



Seed plants, 5-14*, 18* 



Seed plants, origin of, 389 



Seeds, bitter, 11, 419 



Seeds, poisons in, 11, 419 



Selaginella, 332-337* 



Selaginella, life history of, 336 



Selaginella, summary of, 337 



Selection by plant breeder, 500-509 



Selection, natural, 498 



Selective absorption, 36 



Self pollination, 420 



Sensitive plants, 98, 99 



Sepal, 123*, 377 



Sequoia, 42, 46, 73, 482, 495 



Sessile anthers, 127 



Sessile leaves, 88 



Sessile stigma, 128 



Sex, evolution of, 223, 224 



Sex, origin of, 187 



Sexual characteristics given by heter- 



ospory, 352 



Shade plants, 470*, 471 

 Shame vine, 98*, 99 

 Shepherd's purse, development of 



embryo and ovule, 386* 

 Shepherd's purse, development of 



flower of, 387* 

 Shoot, 15 



Short-stemmed plants, 50*, 51 

 Shrubs, 45 

 Sieve plate, 63* 

 Sieve tubes, 61-63*, 67, 72, 76, 



105* 



Sigillaria, 340, Plate VIII 

 Silica, 120 

 Simple leaves, 91 

 Simple pistil, 128 

 Simple umbel of cherry, 133* 

 Siphonales, 197-201* 

 Siphon algae, 197-201* 

 " Sleep " of plants, 97, 98* 

 Slime molds, 169 

 "Smilax," 56* 



