INDEX 



409 



pollen grains, 346-34 8 , 35 1. 355, 



358, 385 



pollen sac, 346, 347, 351 

 pollen tube, 347, 349, 350, 351, 



385 



pollination, 351, 354 

 pollination, cross, 351, 355, 358 

 pollination, self, 351, 358 

 polysaccharides, 40, 41, 49, 396 

 Potato blight, 175-177 

 potential energy, 25, 38, 42, 81, 



85, 121 



principal rays, 335, 336 

 protandrous, 356, 357 

 proteans, 45, 272, 377 

 protein cells, 272, 274 

 proteins, 42-44, 49, 61-63, 73, 77, 



122, 130, 142, 151, 154, 272, 



278, 375, 377, 38i, 390, 392 

 prothallus, 244, 245, 248-251 

 Protista, 30, 392 

 Protococcus, 72-74, 80, 92, 93 

 protophloem, 324, 332 

 protoplasm, 31, 32, 33, 36, 56, 58, 



61-64, 64-70, 76, 77, 82, 84, 



100-101, 389, 404 

 protonema, 240 

 protoxylem, 295, 296, 297, 322- 



325 



pseudopodium, 62, 65, 68, 71 

 Pteridophytes, 29, 243-251, 384 

 Puccinia, 178-181 

 pulses, 381 



pure culture, 147, 148 

 " pure strains," 67, 149 

 putrefaction, 151 

 pyrenoid, 72, 73, 185, 186, 190, 



207, 208, 209 

 Pythium, 172-175 



rays, 295 



receptacle, 345, 353, 354, 365-368 

 reproduction, 71, 73, 87, 184 

 respiration, 39, 81-83, 118, 121, 



132, 135, 136, 150, 159, 289, 



305, 376, 377, 39i 

 reversible gel, 54, 62 

 rhizoids, 221, 225, 233, 238, 239, 



241, 244, 245 

 rhizomes, 257, 259-262, 265, 266, 



ringworm, 169 



root cap, 285, 289, 290-292 



root hairs, 241, 289, 290, 294, 296 



root, the, 241, 288-301 



runners, 261 



Rust of wheat, 178-181 



Saccharomyces, 128, 136 



salts, 73, 77, 123, 130, 142, 152, 



159, 186, 217, 220, 240, 241, 



290, 296, 300, 304, 311, 392, 



393. 395 



Saprolegnia, 171, 172 

 saprophytes, 127, 157-168 

 saprophytic, 78, 157, 158 

 sapwood, 337 

 scale leaves, 259, 262, 325 

 secondary meristem, 298, 328, 331 

 secondary rays, 334-336 

 secondary thickening, 255, 298, 



328 



secondary tissue, 298, 329 

 secretory cells, 272 

 seed, 254, 255, 258, 361-364, 



365, 368, 369-372, 375-388 

 Seed Plants, 28, 243, 252, 254, 255, 



344, 384-386 

 semipermeable membrane, 56, 62, 



108, 109 ^ 



sepals, 345, 34 6 , 353 

 sexual differentiation, 184, 190, 



200,205,210 211,234 

 sieve plate, 274 

 sieve tubes, 229, 274, 293, 297, 



311, 324, 332, 333, 337 

 sol, 48-50, 53, 54-56, 61-63, 101, 



389 

 solutes, 48, 55-57, 61, 108, 293, 



296, 299 



solution, colloid, 48 

 solution, crystalloid, 48, 55, 59, 391 

 solution, " true," 48, 59 

 solvents, 48, 55, 56 

 soma, 184, 185, 195, 198, 205, 206 

 species, 27, 42, 43, 67, 148, 149, 



398, 401, 403 



spectrum (of chlorophyll), 113 

 spermophytes, see seed plants 

 sperms (= male gametes) 198, 199- 



201, 212, 223-225, 230, 235, 



236, 244, 245, 248, 250, 251 



spirillum, 139, 148 



spirochsete, 148, 154, 155 



sporangiophore, 160 



sporangium, 160, 161 



spore capsule, 237, 240 



spores, 131, 143-145, 146, 151, 



155, 160-162 

 sporidia, 179, 180 



