INDEX 



809 



Sachs, 337 



Sagebrush, 768, 769, 770 



Sahauro, 711 {see also Cactus) 



Saint John's shoots, 254 



Salicaceae, 702 



Salvinia, 667 



Sand storm, 794 



Sanitation, 523, 575 



Sap, maple, 324; tapping for, 324 



Saprophytes, 30, 506, 512; economic as- 

 pects of, 514; facultative, 506; obli- 

 gate, 506 



Sapwood, 263 



Sargassum, 632 



Sassafras leaf, 111 



Scales, leaf, 19 



Scar, bundle, 246, 247; leaf, 24, 73, 246; 

 terminal bud scale, 247; vein, 247 



Schistostega, 642 



Schultze, 527 



Schwann, 527 



Scientific evidence, 486 



Scion, 293, 419 



Sclerenchyma, 72, 281 



Sclerotia, 569 



Scutellum, 295, 367 



Seasonal aspects, 26-38; autumnal. 27; 

 spring, 36, 36; summer, 37; winter, 

 34, 34 



Seaweeds, 5, 601, 629, 631 



Sedge, 697; family, 697 



Seed coat, 10, 367; fern, 729; plants, 

 678-692 



Seedlings, 296, 388; mangrove, 389 



Seeds, 11, 14, 336, 367, 376, 673, 686; 

 death of, 398; dissemination of, 368; 

 economic value of, 369; formation of, 

 375, 377; germination of, 387-395; 

 longevity of, 396-399 



Selaginella, 669, 670, 672 



Selling, 382 



Sensitive plant, 88, 217 



Sepal, 336, 353 



Sequoia, 275, 276, 679 



Sex, 434, 487 



Sexual reproduction, 371-386, 400, 687; 

 in angiosperms, 687: in bread mold, 

 545; in ferns, 666; in gymnosperms, 

 684; in Laminaria, 632; in liverworts, 

 653; in mosses, 646; in NemaUo7i, 635; 

 in Oedogonium. 618; in Spirogyra, 



620; in Ulothrix. 617: in water mold, 

 547, 548, 549 

 Shade {see Light); leaf, 77, 78-80; plants, 



117 

 Sheath, 18, 86 



Short-day plants, 341, 342, 348 

 Sieve plates, 282, 283; tubes, 282, 283 

 Silicon, 177 

 Silurian period, 723 

 Slime molds, 562 

 Smuts, 558, 581; of barley, 559; of corn, 



558, 559; of oats, 558; of wheat, 558 

 Snow plant, 31, 504; mold, 544 

 Sodium, 177 



Soil, 309, 315, 589; algae, 610; atmos- 

 phere, 315; bacteria, 531-540; clay 

 loam, 320; distribution of roots in, 

 307, 308, 318; field capacity of, 319; 

 particles of, 316; profiles, 317, 318 

 Sol, 62 



Solanaceae, 715 

 Solutes, 202 

 Solutions, 61, 202 

 Solvent, 202 

 Sorus, 664 

 Soybean, 709 

 Spadix, 358, 360, 361 

 Spallanzani, 528 

 Spanish "moss," 15, 508 

 Spathe, 358 



Species, 18, 24; dominant, 40, 753: new, 

 431, 495; plastic, 82; subdominant, 

 753 

 Spectrum, 27, 115 

 Spermagonia, 561 

 Spermatium, 561, 635 

 Spermatophytes, 678-692 

 Sperms, 372, 465, 466, 647 

 Sphagnales, 649 

 Sphagnum, 649, 650 

 Spike, 357, 360, 696 

 Spines, 18, 83, 86, 258 

 Spirodela, 15 



Spirogyra, 616, 619, 620, 636 

 Spontaneous generation, 525 

 Sporangia, 545, 631, 632, 644, 665 

 Spore, 545, 553, 616, 632, 636, 665; 



print, 554 

 Sporophylls, 379, 665 



