INDEX 



655 



Davenport, C. B., "bleeders," 524 



Mendelism in sheep, 470 



ovarian regeneration, 487 

 Davenport, E., corn experiments, 328 



dynamic evolution, 438 



horses, 496, 497 



prepotency, 573 



telegony, 565 

 Davis, chromosome counts, 285 



CEnothera, 247, 248 

 investigations, 283 

 seed sterility in, 283 

 Deciduous tree fruits, 393 

 Decreased vigor in species hybrids, 230 

 Deer, antlers in the male, 214 

 Deeringia celosiodes, chimeras in, 381 

 Defectives, proportion of, in population, 526 

 Defects in domestic animals, 526 



in man, 524 



inheritance of, 524 

 "Deficiency," in Drosophila ampelophila, 121, 



194 



Descriptions, need of accurate, 428 

 Determination of sex, 536 

 Determiners, 71 

 Detlefsen, agouti factor, 575 



Bos species hybrids, 520 



Cavia species, 235, 236 



Cavy hybrids, 223, 225, 542, 543 



guinea-pigs, 558 



species hybrids, 236 

 Development of the individual, 3 

 Dewey, purple-leaved hemp, 270 

 Dianthus, hybridized, 438 



vegetative vigor in species hybrids, 230 

 Dichotomy, method of, 96 

 Differences between variations, 18 



in organisms, 1 



minute, heritable, 451 

 Digitalis, 438 



matroclinous Fi in species hybrids, 229 . 



purpurea X D. ochroleuca, 230 

 Dihybrid ratio, 86 



modified, 89 

 Dihybridism, 81 



in Drosophila, 87 

 Dimorphism fixed, 48, 276 



in plants, 275 

 Dioecious plants, 317 

 Direction of variations, 20 

 Discontinuous variations, 18 



in horticulture, 274 

 Disease and animal breeding, 522 



defined, 522 



immunity to, 527 



inheritance of, 522 

 Disease-resistance, nature of, 401 



of species, 401 



testing for, 416 

 Disease-resistant plants, breeding, 295, 400, 413 



strains, selecting, 417 

 Diversity, germinal, in populations, 317 



of ancestry in domestic animals, 460 

 Dog, telegony, 565, 570 



Domestic animals, variation in, 454 

 characters of, 454 

 diversity of ancestry, 460 

 germ-plasm of, 450, 460 

 Mendelism in, 465 

 mutations in, 462 

 species hybridization in, 515 

 fowl, origin, 461 

 plants, varieties of, 302 

 Domesticated animals and plants, mutations, 



282 



Domestication and fertility, 551 

 Dominance, 69 



and hetcrosis, 232 

 defined, 144 

 extent of, 144 



in round and wrinkled peas, 145 

 Dominant factors and heteroeis, 231 

 mutations, 267, 274 

 reaction system, 242 

 Doncaster, aberrant sex-ratios, 208 

 Abraxas, 206 

 sex-differentiator, 209 

 Dorsey, apple, 393 

 Downing, hybridization, 294 

 Drosophila, architecture of germ-plasm, 459 

 chromosome number in species, 263 

 mutations comparatively rare, 267 

 reaction system concept, 575 

 viability of mutants, 321 



Drosophila ampelophila, abnormal abdomen, 26 

 allelomorphic relations in, 145, 146 

 bar eye in, 149, 152 

 chromosomes in, 57, 58 

 different factors producing similar effects 



in, 141 



dihybridism in, 87 

 dominant mutations, 267 

 eye-color factors, 194, 215 

 factor differences causing decreased vigor, 



233 



causing sterility, 234 

 factors affecting fertility, 554 

 genetic investigations in, 9, 126, 007 

 giants and dwarfs in, 130 

 inbreeding, effects in, 553 

 inheritance of sex in, 66, 67 

 lethal factors in, 132, 133 

 linkage in, 110, 127, 162 

 miniature wings in, 146, 170 

 modifying factors for eye color, 192 

 multiple allelomorphism in, 156, 161 

 mutations in, 29, 154 

 non-disjunction in, 198 

 pigmentation in, 261 

 return mutations in, 154 

 segregation in, 64 

 sex in, 196 

 size differences, 177 

 truncate-winged, 168 

 white eye color in, 74, 87, 197, 208, 269 

 Drosophila melanogaster = D. ampelophila. 

 Duchesne, hybrids, 438 

 Duchess Shorthorn cows, 556, 580 



