656 
Duck, effects of Castration in, 550 
Rouen, 548 
secondary sexual characters, 548 
Duplicate factors, 136 
Dwarf beans, 175, 177 
maize, 174 
rootstocks, 383 
sweet peas, 175 
E 
Ear-to-row method, danger of, 334 
in maize, 327 
East, bud selection, 394, 395 
corn breeding, 356 
genotypes in maize, 326 
germinal variations, 369 
inbreeding in maize, 325 
increased yield from hybrids, 353 
maize, 292, 293, 295 
multiple factor theory of size inheritance, 
185, 194 
Nicotiana hybrids, 228 
regression away from mean, 56 
tobacco, corolla length, 181, 182, 183 
East and Hayes, flint * sweet corn crosses, 83, 84 
heterozygosis, 231 
inbreeding in maize, 325, 353 
inheritance in corn, 101 
Nicotiana crosses, 232 
segregation of starchy and sweet endo- 
sperm, 79 
somatic variation, 272 
tobacco mutation, 177 
vigor in F\ hybrids, 326, 354, 355 
Ecological variations, 18 
Economy of time in breeding maize, 356 
Ectogenetic variations, 20 : 
Education, service of genetics in, 450 
Effect of castration in animals, 548 
of selection in maize, 333 
in pure lines, 257 
of self-fertilization, 256 
Egg plant, graftage of, 374 
on tomato, effect, 383 
production in fowl, and mass selection, 457, 
498 
and pigmentation, 506 
fecundity, 497 
mean monthly, 505 
sex-linked factor for, 209 
winter, 456, 506, 559 
Elwagnus pungens, 18 
Elderberry, Variegated Black, chimeras in, 381 
Elderton, goodness of fit, 102 
Elliot, Lamarck’s laws, 482 
Elm, F; hybrids in, 365 
Huntingdon, an /'; hybrid, 365 
Emerson, beans, 175 
multiple allelomorphs, 160 
regression away from mean, 56 
somatic variation, 272 
test of hybrid gametes, 159 
Emerson and East, ear-to-row selection, 356 
INDEX 
Endosperm texture, inheritance in maize, 84, 105 
Endothia parasitica, 406 
Englehart, oranges and lemons, 391 
Environment and egg-production, 457 
and plant diseases, 400 
and mutations, 370 
conditions development, 25 
may cause new characters, 26 
modifies development, 21 
Eosin eye color in Drosophila, 156, 192 
Equipment of animal breeder, 450 
Equus caballus X asinus, 228, 516 
hybrids, 468, 520, 557, 567, 570 
sterility of, 557 
Erica, species hybridized, 438 
Erikson, rust resistance, 412 
Erisyphe graminis, 412, 413 
Errors, accidental, 429 
experimental, 429 
probable, 45, 47, 430 
residual, 429 
Eucalyptus globulus, dimorphic leaves, 275 
Eugenics, 11 
Euonymus, 381 
Evans, apple breeding, 295 
Evans, H. M., chromosomes in man, 538 
Evolution and mutations, 276 
and natural selection, 276, 439 
““dynamic,”’ 483 
no longer questioned, 480 
role of factor mutations, 286 
Ewart, domestic animals, 460 
quagga, 566 
telegony, 567, 568, 571 
zebra hybrid, 468 
Exceptional offspring, non-disjunction, 199, 200, 
201, 202, 203 
Experimental breeding, method of, 6 
cytology, method of, 9 
errors, in variety testing, 429 
in reduction of, 431 
morphology, method of, 10 
results, factors affecting, 433 
Extracted dominant or recessive, 73 
Eye color in Drosophila, 194, 215 
F 
Factor, behavior predictable in Drosophila, 117 
complex in a breed, 478 
and hybrid vigor, 559 
and prepotency, 575 
conception of heredity, 110 
constancy, belief in, 193, 194 
contamination, assumed by Castle, 189 
cotton leaf, 179 
coupling and repulsion, 126 
differences causing decreased vigor, 233, 554 
causing size differences, 194 
explanation of reversion, 170 
expression, variability in, 134 
for variegation, 273 
interactions, types of, 163 
Digitized by Microsoft® 
