INDEX. 



291 



Stems, geotropism of, 306, 307 



St ieotropism, see Thigmotropism 



Stigeoclonium, reproduction, 368, 

 369 



Stigma, secretion on, 139; sensitive 

 to contact, 351 



Stimulants, 330 



Stomata, 49, 143; structure, 145; 

 mechanism of opening and clos- 

 ing, 145-147 ; function of auxiliary 

 cells, 145, 148; size, 149; propor- 

 tion to leaf surface, 149; condi- 

 tions of opening and closing, 148- 

 150 ; witli iixed guard cells, 151 



Storage of foods, 160 



Sulphur, 97, 98 



Sulphur-bacteria, 30, 98 



Sunlight, see Light 



Temperature, fatal, 8, 9 



Tendrils, 241-344 



Thermotaxis, 221 



Thermotropism, 321 



Thigmotropism, 247 



Tides, effect on growth, 190, 191 



Tonoplast, 106 



Toxic substances, see Poisons 



Traction, influence on growth, 187, 188 



Transfer of nutrient solutions, 116-135 



Translocation of foods, 63, 155, 156 



Transpiration, 136-141 ; conditions, 

 136, 137; difEerence from evapora- 

 tion, 137 ; means of reducing, 137, 

 138; means of Increasing, 138; in 

 moist tropics, 138-140; move- 

 ments Increasing, 143 



Traumatropism, 247 



Trees, heights, 119 



Tropical plants, transpiration in, 138- 

 140 



Turgor, definition. 111 ; relation of 

 potassium salts, 99; relation to 



growth, 171-173 

 Twining plants, 245, 246 



U 



Utrioulakia, 85 



Vascular bundles, 117 



Vaucheria, reproduction, 364-366, 



375 

 Viola, reproduction, 374, 375 

 ViscuM, 86-88 

 Vitality, suspended, 10 



W 



Water, vehicle of food materials, 6; 

 essential component of active 

 protoplasm, 6-8 ; in air-dry seeds, 

 8; in soil, 104, 105; conducting 

 tissues, 117, 118; ascent of, 119- 

 133, 137, 131, 133; storing tissues, 

 134; secretion, 136-138; pores, 

 138; glands, 138; flow, 132, 133, 

 136; relation to growth, 167; ef- 

 fect on growth, 323-236 



Water-currents, effect on growth, 189, 

 190 



Waves, effect on growth, 190, 191 



Weber's law, 336 



Weeping, 133, 134-136 



Winds, 189, 326 



Winter-killing, 150 



Xerophytes, 95 



Zinc, 95 



"Zinc soil flora," 95 



Zoospores, influence of contact, 240, 



347 

 Zymase, 33 



