INDEX 



583 



native capacity, 98-101; types, 



58-67. 

 Segregation and purity of gametes, 



543. 

 Segregation and reduction division, 



554. 



Selaginella, 438; described, 440-444. 

 Selection, 557. 

 Selection of mutants, 561. 

 Selective absorption, 159. 

 Self-pollination, 48. 

 Semi-permeable membrane, 117. 

 Sepals, 11, 10*, 11*. 

 Sessile leaf, 235, 235*. 

 Seta, 420. 

 Sex cells, 302. 

 Sex organs, 302. 

 Sheep Sorrel, 479*. 

 Sieve tubes, 131. 

 Silphium perfoliatum, 236*. 

 Simple stems, 167. 

 Sinigrin, 283. 

 Siphonales, 302; described, 316, 316*, 



317*. 



Smartweed, 479*. 

 Smuts, 384; described, 392-396. 

 Soil, as the home of roots, 152-162; 



as an ecological factor, 502; 



microorganisms, 155; origin, 152; 



rock constituents, 152; solution, 



157; water, air, and humus, 153. 

 Solonaceae, 491. 

 Solanin, 283. 



Solanum Carolinense, 492. 

 Solanum nigrum, 491. 

 Solanum rostratum, 492. 

 Solitary flowers, 27. 

 Solsola Kali, var. tenuifolia, 480*. 

 Somatoplasm, 532. 

 Soredia, 381. 

 Sorus, 429, 430*. 

 Sour Cherry, 212, 212*. 

 Spawn of the Mushroom, 387. 

 Special forms of leaves, 270-273. 

 Species, in classification, 291. 

 Spermatophytes, 292; described, 445- 



470. 

 Sperms, 302. 



Sphagnales, 417; described, 422-424. 



Sphagnum, 422, 423*. 



Spike, 17, 29, 29*, 32*. 



Spikelets, of Corn, 17, 18*, 19*; of 

 Oats, 20, 20*, 21*; of Wheat, 22, 

 22*. 



Spindle fibers, 124. 



Spiral vessel, 188, 189*, 190*. 



Spirillum, 341. 



Spirogyra, 315, 315*. 



Spongospora subterranea, 341. 



Spongy tissue^ 249, 250*. 



Sporangia, 320, 338. 



Sporangiophore, 437. 



Spore, 338; of Bacteria, 343, 343*. 



Sporidia, 394. 



Sporophore, 383. 



Sporophylls, 437, 439, 441, 447, 448, 

 452, 453, 454, 460, 462. 



Sporophyte, of Angiosperms, 459- 

 463; of Cycads, 446, 446*; of 

 Equisetales, 436-437; of Ferns, 

 426-431; of Liverworts, 411, 

 410*; of Lycopodium, 439-440; 

 of Moss, 418, 418*; of Pines, 452- 

 455; of Selaginella, 441, 440*. 



Spurge family, 486. 



Squash, arrangement of flowers, 27*. 



Squirting Cucumber, 88, 87*. 



Stamens, 11; described, 41, 41*. 



Staminate flower, 13; of Corn, 17, 16*, 

 17*; of Pumpkin, 12*. 



Staminate strobilus, 446, 447, 447*; 

 of Pines, 452, 452*, 453*. 



Standard, 23, 23*. 



Starch, as a storage product, 278; 

 formation, 255; test for, 256. 



Starch grains, 256, 256*; structure, 

 278, 278*. 



Starch sheath, 147, 192, 193*. 



Starchy endosperm, 64. 



Stemonitis, 337*. 



Stems, aerial, 172; branching, 167; 

 characteristic features, 166; 

 classes, 170; climbing, 175; erect, 

 173; functions, 168; growth, 213- 

 221; of Ferns, 427; of herbaceous 

 Dicotyledons, 192-197; of Mono- 



