INDEX 
Macrozanonia, seed of, 288* 
Magnesium, 175 
Maguey fibers, 132 
Maidenhair fern (Adiantum), section 
of stem of, 386* 
Maize, 213 
Male nuclei in Spermatophyta, 405 
Male prothallus and fertilization of 
Cycadales, 409-410. See Megaspo- 
rangium 
Mangifera indica (mango), drupe of, 
278* ; lenticel of, 154* 
Mangrove, 2038, 295, 460-462 
Manihot glaziovii, 127 ; 
Manila hemp (abaca), 1382, 189-140 
Manubrium, 329 
Maple sap, 184 
Maple sugar, 140, 142, 289 
Maranta, starch grains of, 45* 
Marchantia, 374-377 
Marchantiales and Jungermanniales, 
374-379 
Marigold, 220* 
Marine vegetation, 458 
Maturation, 159; of root, 178-180 
Mechanical tissues in stem, 185-140 
Mechanism, explosive, 288 
Megasporangium, 403-405 ; of angio- 
sperms, 430-431; of Coniferales, 
421; of Cycadales, 407, 409, 410, 412*, 
413*, 417, 418*; of gymnosperms, 
407; of pine, 422-424; of Selaginella, 
400-401; of Spermatophyta, 403*, 
405-407 
Megaspore mother cell, 229 ; of orchid, 
428*; of pine, 404. See Megaspo- . 
rangium 
Megaspores, 229 ; of orchid, 428*. See 
Megasporangium 
Megasporophylls, of angiosperms, 429- 
430; of Cycadales, 407-408; of 
Zamia, 411*,. See Megasporangium 
Melon, 279 
Membrane, nuclear, 224; plasma, 41- 
42; semipermeable, 40-42 
Mendel, 232 
Mendelism, 232-247 ; application of, 
247; complementary factors, 242- 
244; cumulative factors, 244-246 ; 
dominance, 236-238 ; inheritance of 
two pairs of characters, 288-240 ; 
linkage, 241; trihybrids, 241-242 
Mercury, 52 
Merismopedia, 310* 
Meristem, 97, 98; secondary, 154 
Merrillosphaera africana, 321* 
475 
Mesocarp, 278 
Mesophytes, 12*, 18 
Metabolism in protoplasm, 21 
Metaphase, 224, 226 
Metaxylem of dicotyledonous stele, 
121 
Micropyle, 222, 281, 405; of angio- 
sperms, 430, 432 ; of Cycadales, 409; 
of pine, 423 ; of Spermatophyta, 404, 
405. See Megasporangium 
Microsporangia, 404; of Coniferales, 
421; of Cycadales, 407, 409*; and 
microspores of Spermatophyta, 405 ; 
of pine, 423; of Selaginella, 400. 
See Microsporophyll 
Microspores, of angiosperms, 430, 431- 
432 ; of Hlodea, 480 *; of pine, 426* ; 
of Selaginella, 400-401; of Sper- 
matophyta, 403, 404, 405. See Pollen 
grains 
Microsporophyll, 405 ; of angiosperms, 
429-430 ; of Cycadales, 407-408, 409, 
410*; of pine, 423; of Selaginella, 
400-402 
Middle lamella, 25 
Midrib, 27, 33 
Milkweed (A sclepias curassavica), fruit 
of, 276*, 284 
Millet, root of, 180*, 181* 
Mimosa pudica (sensitive plant), leaves 
of, 92, 93*; pod of,-277*; root. of, 
308* 
Mineral saits, absorption of, 184-185 ; 
accumulation of, 185; in protoplasm, 
20; in root, 175; in transpiration, 
57-59 
Minimum temperature, 160 
Mints, 137 
Minute seeds, 288 
Mistletoe, 13 
Mitosis, 224, 225*; heterotypic, 229- 
231 
Modifications of structure, acquired 
and hereditary, 64 ; distribution of, 
65 
Moist regions, chlorenchyma in, 60-61 
Moisture, soil, 188-189 
Molds, 348*, 349 
Molecules, 10 
Monocotyledonous 
139-140 
Monocotyledons, 28, 115, 279, 428 
Moneecious plants, 206-207 
Monosaccharides, 289 
Monotropa (Indian pipe), 14* 
Monsoon forests, 450-452 

stems, 129-138, 
