INDEX 
(References to illustrations are indicated by asterisks accompanying page num- 
bers. When an asterisk precedes the citation of a group of pages, it means that 
several illustrations are included) 
Absorption of carbon dioxide, 13, 14 
Absorption of water by roots, 9, 
23-25 
Accessory buds, 95*, 96* 
Acer saccharum, 309, 310* 
Achene, 167*, 304 
Actinomorphic, 129 
Adventitious buds, 96, 98* 
Aérial roots, 80*, 31*, 73% 
Agriculture, 197, 308-332. See also 
topics such as Plant Breeding, 172- 
193 ; Fungous Diseases of Plants, 
234-261; and Weeds, 333-342 
Air, relation to germination, 161 
Air chamber, 36* 
Air passages, 85* 
Air plants, 31, 48, 49*, 50 
Air roots, 30*, 31, 73* 
Air supply of roots, 26*, 27, 28, 321 
Albuminous substances. See Proteins 
Alfalfa, nitrogen production by, 205 
Alge-fungi, *235-242, 261 
Alge, *219-233 
Alge, classification of, 260, 261 
Alge, and water supply, 229, 230 
Alternate branches, 96* 
Alternate leaves, 70*, 71 
Alternation of generations, 266 
Amanita, 258* 
Ament. See Catkin 
Anchorage, 8*, 9, 25 
Angiosperm, life history of, *208-304 
Angiosperm flower, 14*, 15*, *125- 
154, *298-302 
Angiosperms, 282, *296-807 
Animal food, plant sources of, 7, 40, 
47 
Annual ring, 12*, 65*, 66 
Annual thickening, 12*, 65*, 66, 67 
Annuals, 12, 44 
Anther, 128*, 129* 
Antheridium, 264, #265, *269, *275 
Anthrax, 203 
Antipodal cells, 136*, 301* 
Antitoxins, 212, 213 
Apetalous, 127* 
Apple, branch arrangement of, 96* 
Apple, leaf arrangement of, 70* 
Apples, 191*, 315-319 
Aquatic plants, 78*,79*, 85*, 219 
Arbor vite, 293* 
Archegonium, 264, *265, *269, #275 
Aristolochia stem, cross section of, 
62*, 63 
Arrangement of leaves, *70-73 
Arum, pollination of, 147*, 148 
Ascocarp, 244*, 245 
Ascomycetes, *243-247, 261 
Ascophyllum, 230 
Ascospores, 244*, 245 
Ascus, 244* 
Asexual reproduction, 225 
Asparagus rust, 254 
Assimilation, 46 
Atrichum, 263*, 265* 
Axillary bud, 95*, 96* 
Bacteria, 39, *199-218 
Bacteria, classification of, 260 
Bacteriology, 197 
Bark, 10, 11, 12*, 20, 65*, 105* 
Basidiomycetes, *251-260 
Bast, hard, 20, 62*, 64* 
Bast, soft (sieve tubes), 20*, 43, 63* 
Bean seed, 158* 
Beefwood, 56* 
Bees, 146*, 150* 
Berries, 157 
Biennial, 12, 44, 73, 74 
Big tree, 287%, 204, 296 
Bilaterally symmetrical flowers, 128*, 
129 
359 
