INDEX. 



291 



Stems, geotropism of, 306, 207 



St reotropism, see Thigmotropism 



STIGEOCLOXIUM, reproduction, 268, 

 269 



Stigma, secretion on, 129; sensitive 

 to contact, 251 



Stimulants, 230 



Stomata, 49, 142; 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; with fixed guard cells, 151 



Storage of foods, 160 



Sulphur, 97, 98 



Sulphur-bacteria, 20, 98 



Sunlight, see Light 



Temperature, fatal, 8, 9 



Tendrils, 241-244 



Thermotaxis, 221 



Thermotropism, 221 



Thigmotropism, 247 



Tides, effect on growth, 190, 191 



Tonoplast, 106 



Toxic substances, see Poisons 



Traction, iufluence s on growth, 187, 188 



Transfer of nutrient solutions, 116-125 



Translocation of foods, 63, 155, 156 



Transpiration, 136-141 ; conditions, 

 136, 137; difference from evapora- 

 tion, 137 ; means of reducing, 137, 

 138; means of increasing, 138; in 

 moist tropics, 138-140; move- 

 ments increasing, 142 



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 



UTRICULAKIA, 85 



Vascular bundles, 117 



VAUCHERIA, reproduction, 264-266, 



275 



VIOLA, reproduction, 274, 275 

 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- 

 123, 127, 131, 133; storing tissues, 

 124; secretion, 126-128; pores, 

 128; glands, 128; flow, 132, 133, 

 136; relation to growth, 167; ef- 

 fect on growth, 222-226 



Water-currents, effect on growth, 189, 

 190 



Waves, effect on growth, 190, 191 



Weber's law, 236 



Weeping, 132, 134-136 



Winds, 189, 226 



Winter-killing, 150 



Xerophytes, 95 



Zinc, 95 



"Zinc soil flora," 95 



Zoospores, influence of contact, 240, 



247 

 Zymase, 33 



