684 



BOTANY OF THE LIVING PLANT 



Meesia, sexual organs of, 466 (Fig. 



361). 



Megasporangium, the female spor- 

 angium containing one or more 

 megaspores. In Flowering Plants 

 it is the ovule : 288, 295 (Figs. 

 216, 217). 



Megaspore, where spores are sexually 

 differentiated the female spore. 

 In Seed Plants it is the embryo- 

 sac : 294 (Fig. 216) ; development 

 of, 296 (Fig. 217), 298 (Fig. 219), 

 352, 535 (Fig- 423).- 539 ; retention 

 of, 55 1 - 



Meiomery, where the number of parts 

 of one category stands below the 

 fundamental number for the flower, 

 268. 



Meiosis, the process whereby the 

 chromosome number is halved 

 (" reduced "), 353, 562, 563 (Figs. 

 430-433) ; meiosis and Mendelian 

 segregation, 572 (Fig. 436) ; and 

 linkage, 580 (Figs. 440, 441). 



Membrane, permeable or semi-per- 

 meable, 35. 



Mendelian segregation, see Segrega- 

 tion. 



Mendel's laws, 569-572. 



Meristele, of Ferns, 486, 487 (Fig. 

 376) ; structure of, 488 (Figs. 377, 



378). 



Meristic differences, differences in the 

 fundamental number of parts in 

 different flowers, 265. 



Meristic variation, divergence in cer- 

 tain cases in the number of parts, 

 where a definite number is usual ; 

 as in successive whorls of leaves : 

 202, 265, 604. 



Merulius, Dry Rot Fungus, 442. 



Mesocarpus, 374. 



Mesophyll, the parenchyma between 

 upper and lower epidermis of the 

 lamina, 72 (Figs. 47, 48) ; of 

 Narcissus, 119 (Fig. 79). 



Mesophytes, plants living under con- 

 ditions that are not extreme, 212. 



Meso-rachis, 351. 



Metabolism, chemical change with- 

 in the organism, 30: 114, 134, 



137- 

 Metamorphosis, Goethe's theory of, 



277 ; sporangia, due to, 352. 

 Metatrophic bacteria, 451. 

 Metaxylem, the later-formed part of 



the primary xylem, 85 (Fig. 59). 

 Miadesmia, seed-like organ of, 521. 

 Micropyle, a narrow channel leading 

 • to the apex of the nucellus of an 



ovule : the channel for the pollen- 

 tube, 295 (Fig. 216). 



Microsporangia, 352. 



Microspore, where spores are sexually 

 differentiated, the male spore, 

 characterised by its smaller size. 

 In Seed Plants the pollen-grains 

 are microspores : 286, 352 ; of 

 Selaginella, 515, 517 (Figs. 407, 



4"). 540- 



Middle lamella, 112. 



Migration to land, 547. 



Mildews, 393, 418 ; general account 

 of, 419; (Figs. 317-319). 



Mimosa pudica, sensitive plant, 162 

 (Fig. 98) ; movement under me- 

 chanical shock, 163. 



Mistletoe (Viscum), parasitism of, 140, 

 222. 



Mitosis, division of the nucleus in 

 connection with the division of 

 somatic cells, 562 (Figs. 428, 429). 



Mnium, conducting tissue of, 464. 



Mobilisation of reserves, 130. 



Modification, a (non-inheritable) fea- 

 ture of an individual, directly re- 

 lated to environmental influences, 

 569. 586. 



Molinia, mechanical construction of 

 stem, 185 (Fig. 119). 



Monkey-nut, geotropism in, 154. 



Monkey-puzzle (Araucaria), 527 ; leaf 

 arrangemeut of, 203 (Fig. 136). 



Monkshood (Aconitum), pollination 

 of, 302 ; flower of, 624 (Figs. 475, 



473. A). 

 Monoblepharis, 411 (Fig. 311). 

 Monocotyledons : Seed Plants (Angio- 



sperms) having an embryo with 



one seed-leaf : stem of, 50 (Figs. 



28-31), 67 ; stomata, 76 (Figs. 



50, 51) ; root of, 84 (Fig. 58) ; 



mechanical construction of stem, 



182 ; of leaf, 187 (Figs. 120-122) ; 



embryology of , 314 (Figs. 232, 233) ; 



flowers of, 606-619 (Appendix A) ; 



stelar structure of, 596. 

 Monopodial branching, where a new 



branch arises laterally below the 



apex of the original part, 511. 

 Monosaccharides, 123. 

 Monotropa, ectotrophic mycorrhiza 



of, 229 ; nucellus and embryo-sac 



of, 298 (Fig. 219). 

 Morchella (Morel), 400 (Fig. 298) ; 



418 ; 426 (Fig. 324) ; asci of, 417 



(Fig. 316). 

 Mortal disease, 235. 

 Moss-plant, origin on protonema, 



463 ( Fi g- 357)- 



