Index 



359 



Silk oak (Grevillea), 247 



Sitka spruce, 274 



Skunk-cabbage (see " Lysi- 

 chiton ") 



Slime-molds, 27 



Smilax, 201 



Snowdrop, 166, 251 



Snow-plant (see " Sarco- 

 des ") 



Soil, a factor in plant-distri- 

 bution, 245 



Solatium nigrum, 341 



Solomon's seal, 274 



Sour-gum (see"Nyssa") 



South America, flora of, 247 



Southern Hemisphere, flora 

 of, 248 



Spanish broom, 199 



Spanish moss (see " Tilland- 

 sia") 



Sparganium (see " Bur- 

 reed ") 



Species, defined, 310 



Sperm, Spermatozoid, 28, 45, 

 67, 99, 106, 125, 126, 133, 

 138; Club-moss, 106; Fern, 

 99; Seed-plants, 125 



Sphserotheca, 75 



Spirogyra, 203 



Sponges, 14, 52 



Spontaneous generation, 4 



Sporangium, 97, 103 



Spores, 88, 100, 153, 214, 224 



Spore-fruit (see also " Sporo- 

 carp"), 76 



Sporocarp, 69, 70, 77 



Sporophyte, 69, 88, 90, 92, 94, 

 95. 96, 97, ioo, 102, 121, 

 122, 194; Anthoceros, 95; 

 evolution of, 90; fern, 97, 

 ioo 



Sporophyll, 115, 136, 151, 152 



Sports, 306, 308, 320 



Spring-beauty (Claytonia), 

 171, 274 



Spruce, *I27 



Stamen, 152 



Stem, ioo 



Sterilization, factor in evolu- 

 tion of sporophyte, 114 



Stigma, 156 



Stimuli, 26, 27, 28, 223, 344 



Stomata, 94 



Storage organs, 214, 215 



Strawberry, *i7i 



Strobilus, 115 



Stuartia, 257 



Style, 156 



Sub-cretaceous, flora of, 150, 

 161, 241 



Sub-polar flora, 250 



Surf-algae, 61, 192 



Sugar-beet, 307 



Sugar-cane, 20 



Sun-birds, 180, 234, 235 



Sunflower, 290 



Suspensor, 128 



Suwarro (see " Cereus gi- 

 ganteus) 



Sweet briar, 291 



Sweet gum (see " Liquidam- 

 bar") 



Sweet pea, 177 



Sweet potato, 282 



Symbiosis, 78, 79, 212, 213, 

 217, 218 



Sympetalous flowers, 176, 

 309 



Sympetake, 172, 173 



Syncarpous pistil, 176 



Synchytrium papillatum, 213 



Syringa (Philadelphus), 270 



Tamarack, 145 



Tanbark oak, 274 



Tangelo, 340 



Taro (Calocasia), 286 



Taxodium, 249 



Tea, 282 



Tea-rose, 207 



Tecoma (see "Trumpet- 

 creeper ") 



Temperature, effects of, 36, 

 37, 38 



Terrestrial plants (see 

 " Land-plants ") 



