INDEX 
Volvocales, 15. 
Volvox, 1 8, 70. 
Wastes, 412. 
Water, ascent, 349 ; capillary ascent, 314 ; 
continuity, 301 ; and death, 483 ; entry, 
316 ; exudation, 332 ; immigration, 308 ; 
influx, 325 ; loss, 331 ; migration into roots, 
314 ; movement, 341 ; and plants, 209, 
311; raw material, 366; relations, 301; 
soil, 313 ; solvent, 303. 
Water ferns, 170. 
Water molds, 63. 
Water proofing, 317, 318. 
Weber's law, 448. 
Weismannism, 200. 
Welwitschia, 228. 
Wheat, aleurone grains, 392. 
Wheat rust, 82, 83, 84, 85. 
White rust, 65. 
Witch brooms, 71. 
Wood, heart and sap, 347. 
Xanthophyll, 367. 
Xenia, 271. 
Xylaria, 77. 
Xylem, 124, 241, 342, 343, 344, 345; water 
path, 347. 
Yeast, 70 ; fermentation, 410. 
Zamia, embryo, 200, 201 ; habit, 193; sta- 
men, 195; stem section, 194; strobilus, 
196. 
Zonal development, 254. 
Zoospore, 16, 22, 23, 25, 26, 28, 29, 30, 32, 34, 
35, 45- 
Zygnema, 38, 40. 
Zygnemaceae, 38. 
Zygomorphic flowers, 256. 
Zygomycetes, 67. 
Zygospore, 16, 17, 22, 23, 25, 38, 39. 40. 
Zygote, 1 6. 
Zymase, 410. 
