INDEX 657 
Factor, interpretation of quantitative inheritance, Farmer and Digby, chromosomal dimensions, 264 
195 Primula kewensis, 264 
mutations, 263, 264 Farrell, experimental error, 430 
at maturation, 269, 270 Warrer, grains, 296 
cause variegation, 381 rust resistance, 411 
classes, 265 ; Feeundity in fowls, 497, 559, 560, 574, 585 
conception of, 267 Tern, origin of varieties in Boston, 312 
germinal and somatic, 268 Fertility and the chromosomes, 555 
in Boston fern, 315 and heterozygosis, 559 
in Coleus, 388 capable of improvement, 552 
~ in domestic animals, 462 Darwinian theory of, 552 
in Drosophila, 110, 154, 177, 190, 192, 267, factors affecting, 554 
462, 554 in animals, 551, 563 
in meristematic tissue, 269 in female hybrids, 235, 236 
in @nothera, 285 in species hybrids, 235 
» nature and causes, 266, 273 Fertilization, double in maize, 150, 151 
not of fortuitious occurrence, 268 failure of, 350 
occurrence of, 371 Fiber plants, species and varieties, 302 
produce cultivated varieties, 366 Fire-blight, disease, 407 
réle in evolution, 286 Fischer, modified germ cells, 492 
potency and prepoteney, 575 Flammarion, Coleus, 389 
relations in quantitative inheritance, 174 Flax, 317 
system in stocks, 166 wilt-resistant, 417 
systems affecting a single character, 195 Flower, color in sweet peas, 304 
variability, by hypothesis of, 192 form and size in sweet peas, 304 
Factors, 7, 59, 67, 71 Flowers, composite crossing, 296 
affecting experimental results, 433 diversity of varieties, 302 
alterations in, 263, 267 hermaphrodite, self-fertile, 317 
chemical composition, 267 cross-fertile, 317 
coat color in horses, 466 hybridized in China, 287 
competitive action of, 150 species hybrids, 297 
complementary, 140 Fluctuating modifications, 383 
contamination of, 189 variations, 18, 32, 428, 439 
cumulative, 140 Focke, hybrid, 438 
defined, 129 sexuality, 437 
duplicate, 136 species hybrids, 227, 228, 231 
first, second, third and fourth groups in Féex, phylloxera resistance, 405 
Drosophila, 117 Forms of species hybrids, 227 
for corolla length in tobacco, 183 Forficula auricularia, 48 
for fecundity in fowls, 561 fortuitous variations, 20 
for high and low protein and oil, 333 Four o’clock, see Mirabilis jalapa. 
for stature in sweet peas, 175 Fowls, Andalusian, 152, 476, 514, 579 
four groups in Drosophila, 110 Bantam, 499 
history in a cross, 70, 73 Barred Plymouth Rock, 504, 574, 575 
in a dihybrid cross, 81 Breda, 476 
homologous in species, 224 breeding, for fecundity, 585 
in Antirrhinum, 223 Brown Leghorn, 548 
in Cavius, 223 comb character in, 164 
influencing fertility, 551, 554 Cornish Indian Game, 560, 575 
lethal, 131, 546 creation of bantam varieties, 500 
linear arrangement of, 115 dominant white, 579 
linked in same chromosome, 108 effects of alcohol on, 493 
manifold effects of, 133 of castration in, 550 
modifying, 190, 192, 454 egg production in, 456, 497, 559, 560, 607 
nature and expression of, 129 fecundity factors in, 561 
plotted relations in Drosophila, 116 fecundity in, 497, 559 
potency of sex, 217 hybrid, 521 
producing like somatic effects, 140 Mendelian characters in, 477 
recombination of, in /’s, 186 Mendelism in, 476 
relatively stable entities, 194, 267 ovarian transplantation, 487 
sex, 215, 548 phyletic origin, 460 
sex-linked in X-chromosome, 196, 546, 548 pigmentation and egg production, 506 
system of, in maize, 163 progeny tests, 498 
Fairchild, seed and plant introduction, 299 reyersion in, 171 
42 
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