588 



Subject Index 



Lethals (continued) 



deficiencies and, 391, 392, 393, 427, 



428 

 extra chromosomes and, 417 

 missing chromosomes and, 415, 424 

 mutation rate of, 236, 240, 241, 



244, 245, 246 

 translocations and, 404 

 Lethal mutations, 231, 250-257, 258, 



259, 260, 261 

 Life cycle, 50 

 Lily, 17, 525 

 Line selection, 377, 378 

 Linkage, 147, 148, 155, 156, 171 

 between genes for size and color 



of flowers, 353 

 complete, 152, 154, 161, 162 

 Rh blood types and, 297 

 first case of in autosomes of Dro- 



sophila, 173 

 of size-genes and heterosis, 385 

 Linkage groups, 186, 187, ISS 

 Linkage map, 171, 172, 173, 176, 177, 

 178, 180, 181, 182, 1S7 

 chromosome aberrations and, 189, 



401, 403 

 genetical and cytological com- 

 pared, 189 

 incompletely sex-linked genes in 



man and, 197 

 metaphase chromosome map and, 



191, 192, 193 

 salivary gland map and, 192 

 Linkage with self-sterility alleles, 



274, 275, 276, 277 

 Linum usitatissimum, 323 

 Locus, 17, 18, 19, 27, 28, 68, 71, 77, 



82, 174, 227, 236 

 Lychnis, 73, 101, 103, 483, 507 

 Lymantria dispar, 483, 484, 485, 493, 

 496 



Maize, see Zea mays 



Mammals, 522 



Mapping genes on chromosomes, 

 171 ff., 186, 190 

 by combined genetical and cyto- 

 logical methods, 191 



Mapping genes (continued) 



effect of inert material on, 190, 191 

 Mass selection, 377, 378 

 Maternal-line selection, 378, 379, 



380, 381 

 Matrix, 6, 7, 12, 14, 15, 58, 75, 76, 



216 

 Matroclinous males, 425 

 Maturation divisions, 49 

 Mean, 350, 359 ff., 361 

 Megagametophyte, 51, 503, 504 

 Megaspore, 51, 502, 503, 504, 510 

 Megaspore mother cell, 51 

 Megasporocyte, 51 

 Meiocyte, 213 

 Meiosis, 49 ff., 54, 60, 62, 68, 71, 72, 



154, 480 

 in aneuploids, 415, 416, 417, 418, 



423 

 in generations normally haploid, 



434 

 Melandrium album, 73 

 Melanin pigments, 313 

 Mesoderm, 302 

 Metaphase, 7 ff., 8, 13, 16, 54, 58 ff., 



60, 62, 72, 127, 154, 422, 446, 



447, 448, 460 

 Metaphase chromosome map, 191, 



192, 193 

 Microgametophyte, 51, 503, 504 

 Micronucleus, 394 



Microspore, 51, 63, 502, 503, 504, 510 

 Microspore division, 60 

 Microspore mother cell, 51 

 Microsporocyte, 51 

 Mirabilis jalapa, 540, 541 

 Mitochondria, 3, 4, 540 

 Mitosis, 6ff., 8, 48, 52, 58 ff., 71 

 Modified ratios, 321 ff. 

 Modifying genes, 336, 337, 354, 513 

 Mollusks, 522, 523 

 Monoecious plants, 503, 509, 510, 



512 

 Monohybrids, 81, 127, 130 

 Monoploid, 49, 433 

 Monosomic, 414 ff., 425, 434 

 Mos«, 542 



