508 



INDEX 



146, 148 ; phototaxis, 183-185, 188, 

 199, 202 ; growth, 282 ; thermotaxis, 

 258, 259. 



Vioia, phototropism, 438. 



ViEKORDT, spectrophotometer, 160. 



Villon, green rays and light, 435. 



Vinegar eel, organic acids, 13 ; accli- 

 mated to sodic carbonate, 28. 



Vines, temperature and metabolism, 

 222 ; freezing point for plants, 247 ; 

 growth, 282 ; potassium and growth, 

 318 ; light and growth, 420, 421, 423 ; 

 effective rays in growth, 430. 



Vitis, phototropism, 438. 



Volvox, phototaxis, 183 ; light attune- 

 ment, 206. 



DE Vries, quantitative studies in os- 

 mosis, 71-7.J ; salt-absorption, 88 ; 

 growth and density, 362 ; contact 

 stimulus, 382 ; thigmotropism, 383. 



Wachtel, geotropism, 394. 



Wallek, electric response, 128 ; eleo- 

 trotaxis, 147. 



Ward, bactericidal effect of strong 

 light, 171-174 ; cell division and 

 growth, 287 ; light and growth, 421. 



Warren, electric current on plant 

 growth, 407. 



Was.iiaxx, thermotaxis, 261. 



Water, amount in organisms, 58 ; role 

 in organisms, 59 ; effect on proto- 

 plasm, 67 ; analysis of, 301 ; effect 

 on growth, 360. 



Water animals, hydrazin a poison, 16 ; 

 source of oxygen for, 304. 



Weber, phosphorus and growth, 314. 



Weber's law, 43-45, 440. 



Wettstein, light on development, 174. 



Weyl, heat-rigor, 239. 



Whipple, light accelerating growth, 

 423. 



WiELER, oxygen and plant growth, 

 305 ; growth and density, 362. 



WiESNER, hydrotropism, 257 ; trau- 

 matropism, 384, 385 ; light and 

 seedlings, 417 ; mistletoe, 423 ; 

 Vicia faba, 429; intensity of light 



and response, 438 ; effective rays 

 for seedlings, 440 ; heat and spore 

 germination, 452 ; phototropism and 

 geotropism, 471. 



DE WiLDEMANN, tliermotaxls, 258, 261. 



WiLFARTH, enriching action of le- 

 gumes, 310. 



WiLLEM, light response, 207. 



AViLSON, phototropism of Hydra, 202. 



WiNDLE, electricity and development 

 of chick, 405. 



WiNOGKADSKY, phototaxis, 184 ; nu- 

 trition of bacteria, 299 ; sulphur 

 and bacteria, 315 ; rubidium and 

 growth, 320 ; hydrogen disulphide 

 and bacteria, 326. 



Wolff, silicon and growth, 324. 



V. WoLKOFF, temperature on metabo- 

 lism, 222. 



WoLLKY, atmospheric electricity, 408. 



WoLTEEiNG, iron and growth, 323. 



Worms, formaldehyde, 21 ; electro- 

 taxis, 147 ; phototaxis, 195 ; ultra- 

 maximum, 235 ; ultraminimum, 245 ; 

 acclimatization to high temperatures, 

 251. 



WoRTMANN, chemotropism, 340; hydro- 

 tropism, 358, 360; thigmotropism, 

 381 ; geotropism, 402. 



Wounding, and traumatropism, 384. 



Yeast, phosphorus and growth, 313; 

 potassium and growth, 318. 



YoNG, acclimatization to changed den- 

 sity, 86 ; food of Amphibia, 329, 330 ; 

 density and growth, 367 ; light and 

 growth, 425, 426; light and growth 

 of hydra, 430 ; different wave-lengths 

 on growth of tadpoles, 433-435 ; ex- 

 tent of medium and size of tadpoles, 

 475. 



Zacharias, varying density on proto- 

 plasm, 76. . 



Zea, silicon and growth, 324; phototro- 

 pism, 438 ; temperature and growth, 

 451-455 ; thermotropism, 463-465. 



Zoospores, chemotaxis, 34, 36, 37. 



