INDEX 



(The numbers with stars refer to the pages on which the illustrations are given.) 



Absciss layer, 184. 



Absorption of water, by seeds, 91; by 



roots, 159; factors that hinder, 



160; selective, 160. 

 Absorptive zone, 143, 144*. 

 Abundance and Distribution of 



plants, 5. 



Abutilon Theophrasti, 487. 

 Accessory buds, 206. 

 Aceraceae, 487. 

 Achene, 60, 79, 60*. 

 Achillea millefolium, 24*. 

 Acids, 120; Malic, 287; Oxalic, 287; 



citric, 287; tartaric, 287. 

 Aconite, 482. 

 Acorn, 80, 83*. 

 Actinomyces chromogenus, 348, 344*, 



347*. 



Active buds, 211. 

 Adventitious buds, 206, 207*. 

 Adventitious roots, 140. 

 Aecidiospores, 398, 399*. 

 Aerial stems, 172. 

 Aerobic Bacteria, 343. 

 Aerotropism, 152. 

 After-ripening, 69. 

 Agarics, 385, 385*, 386*. 

 Agaricus campestris, 385, 386*. 

 Agave, 498, 498*. 

 Aggregate fruits, 79*, 80. 

 Agropyron repens, 74. 

 Air chamber, 249. 

 Air, in the soil, 153. 

 Air roots, 163. 

 Albugo, 359. 

 Albumins, 282. 

 Albuminous seeds, 60. 

 Aleuron layer, 64, 65, 66*, 281*. 

 Alfalfa Dodder, 489. 



Alfalfa, seeds, 74, 87, 74*; fruits, 82; 



stem, 193*, 194*; plant, 209*; 



leaf, 238*. 

 Algae, 296. 



Blue-green, 297-301. 

 Green, 301-318. 

 Brown, 318-324. 

 Red, 324-329. 

 in soils, 156. 

 Alkaloids, 285, 286. 

 Allelomorphs, 543, 543*; dominant, 



544; recessive, 544. 

 Alternate arrangement of leaves, 238, 



239*, 240*. 



Alternation of generations, 412. 

 Amanita bulbosa, 384*. 

 . Amaranthus albus, 84*. 

 Amino acids, 120. 

 Amino compounds, 282. 

 Amygdalin, 286. 

 Anabolic metabolism, 274. 

 Anaerobic Bacteria, 343. 

 Anaerobic respiration, 122. 

 Analysis of seeds, 74. 

 Anatomy, described, 2; of leaves, 



242-252; of root tip, 143; of the 



older portion of the root, 147; 



of stems, 182-203. 

 Anatropous ovule, 463. 

 Andreales, 417. 

 Angiosperms, 293, 445; described, 



459; life cycle, 469*; classifica- 

 tion, 471. 



Animals in soils, 157. 

 Annuals, 171. 



Annual rings, 197, 201, 198*, 202*. 

 Annular vessels, 188, 189*, 190* 



195*. 

 Annulus, 386, 429, 385*, 386*, 430*. 



585 



