INDEX 
Selaginella, 132 ; archegonium, 137; embryo, 
137; female gametophyte, 136; habit, 
133; sporangia, 134; spores, 7.35. 
Selection, variable, 307. 
Selective action, 307. 
Sensitive plants, 429. 
Sepal, 252. 
Seta, 100, 101, 103, 104, 105, 113, 116, 120. 
Shoot, permeable regions of, 311. 
Sieve plates, 242, 243. 
Sieve vessels, 242, 243; role, 394. 
Silphium, fertilization, 269; male gameto- 
phyte, 267; microsporangium, 258. 
Siphonales, 33 ; conclusions, 37. 
Siphonostele, 133 ; amphiphloic, 157, 160; 
ectophloic, 157, 162. 
Sleep movements, 455. 
Soil, 312 ; capacity for water, 313 ; effect of 
roots, 315 ; water of, 313. 
Solids, 302. 
Solutes, 303 , entry of, 316 ; natural, 303. 
Solution, 300, 303. 
Solvent, 303. 
Soredia, 79. 
Sorus, 156, 163, 165. 
Spadix, 277. 
Spathe, 277. 
Spectrum, absorption, 368, 369. 
Sperms, 17 ; thallophytes, 18, 19, 28, 30, 36, 
43, 50, 52, 56; bryophytes, 92, 95, 102, 
112, 117; pteridophytes, 128, 120, 135, 
140, 148, 167, 178, 444; gymnosperms, 
100, 201, 211. 
Spermatium, red algae, 56 ; rusts, 83. 
Spermatophytes, 180. 
Spermatozoid, 17, 56. 
Spermogonium, lichens, 79 ; rusts, 83. 
Sphacelaria, 46. 
Sphaerella, 15. 
Sphaerocarpus, 105. 
Sphaeroplea, 27, 28. 
Sphaerotheca, 75. 
Sphagnales, no; conclusions, 114. 
Sphagnum, antheridia, 112; archegonia, 
113; gametophyte, in; habit, 112, 113; 
leaf, ///; sporophytes, 113, 114. 
Sphenophy Hales, 143. 
Sphenophyllum, 143. 
Spiral vessels, 241, 243. 
Spirillum, //. 
Spongy region, leaf, 250, 251. 
Sporangiophore, 143, 146, 333. 
Sporangium, 3 ; thallophytes, j, 27, 45, 58, 
59, 67, 68; pteridophytes, 125, 126, 133, 
134, 139, 142, 143, 144, I4&, 152, I53> 156, 
157, 1 60, 163, 164, 165, 352. 
Spores, 3, 16, 62, 147. 
Sporidia, 83. 
Sporocarp, 171, 172, 173, 174, 176, 177. 
Sporogonium, 95. 
Sporophores, 62. 
Sporophylls, 122. 
Sporophyte, 32 ; thallophytes, 32, 60, 84 ; 
bryophytes, 92, 95, 97, 09, 100, 101, 103, 
104, 105, 108, 100, 113, 114, 115, 116, 118, 
no, 120; pteridophytes, 122, 132, 138, 
143, 149, 156, 171, 176 ; gymnosperms, 181, 
185, 191, 203, 207, 213, 220, 229. 
Spirogyra, 39. 
Sprout chains, yeast, 70, 71. 
Squirting fungus, 68. 
Stalk cell, 200. 
Stamens, 183, 184, 186, 187, 105, 205, 208, 
213, 214, 220, 221, 230, 231, 252, 253, 256, 
257. 
Staminodia, 281. 
Starch, 358, 375, 389. 
Starch grain, 389. 
Statolith theory, 464. 
Stegocarpae, 121. 
Stele, 124, 239, 241. 
Stem, angiosperms, 239. 
Stemonitis, j. 
Sterigmata, 80, 89. 
Stigeoclonium, 26. 
Stigma, 260. 
Stigmatomyces, 78. 
Stigonema, 10. 
Stimulus, 426 ; chemical, 438 ; formative, 
435 ; mechanical, 439 ; morphogenic, 435 ; 
tonic, 449. 
Stink horns, 91. 
Stipe, mushroom, 87. 
Stomata, 109, 146, 250, 251, 319, 320, 327 ; 
regulation of, 327. 
Stomium, 164. 
Stoneworts, 41. 
Storage, 388. 
Straightening, twiners, 469. 
Strains, sexual, 68. 
Streaming, 444, 451. 
Strobilus, 122 ; pteridophytes, 124, 132, 133, 
144; gymnosperms, 186, 187, 188, 189, 
192, 193, 195, 196, 204, 205, 206, 208, 209, 
213, 214, 220, 221, 222, 228, 229, 230, 231, 
232; theory of, 123. 
Stroma, chloroplasts, 367 ; fungi, 76, 77. 
Style, 260. 
Substratum, fungi, 61. 
Sugar, 390 ; cane, 359 ; fruit, 359 ; grape, 
359- 
Sulfur, source of, 379. 
Summation, 432, 462. 
Sundew, 387, 454. 
Sunflower, nutation, 424. 
Suspensor, angiosperms. 271, 272, 273, 274; 
