672 
Species, peculiarities in hybridization, 342 
universal indicator, 234 
Specificity of proteins and carbohydrates, 266 
Spencer, acquired characters, 6, 480 
germinal theory, 489 
on Darwin, 5 
Sperm, male and female producing, 196, 540 
Spermatozoa, dimorphism in, 540 
in Equus hybrids, 520 
Spillman, polled cattle, 463 
swine, 476 
Spindle, 60, 61, 64 
Spindle Tree, chimeras in, 381 
Spireme, 59 
Sports, bud, 270, 298 
in sweet peas, 304 
utilization of, 302 
Spragg, alfalfa, 417 
barleys, 340 
Sprengel, hybrids, 438 
Squash, 317 
Standard deviation,'calculation and significance, 41 
diminished during selection, 188 
of a Mendelian ratio, 100 
of an F2 population, 184 
Standardization of varieties, 432 
Stapels-Brown, reversion in pigeons, 172 
Starch grains, in round and wrinkled peas, 145 
stereoisomeric forms of, 266 
Starkman and Piemeisel, wheat rust, 412 
State associations of breeders, 301 
Statistical method, employment and value of, 56 
Steinach, ovarian transplantation, 550 
Stereoisomeric forms of organic substances, 266 
Sterility of hybrids, 556 
in animals, 555 
in species hybrids, 227, 228, 234, 236, 238 
Stewart, degeneration in potatoes, 397 
St. Hilaire, fertility, 438 
Stizolobium deeringianum, 367 
Stockard, effect of alcohol on guinea-pigs, 30, 493 
Stock and scion, reciprocal effects, 383 
Stockberger, experimental error, 430 
Stocks, see Matthiola. 
von der Stok, intergeneric hybrids, 296 
Stout, Coleus, 386, 387, 388, 389 
Strain tests at Svaldf, 425 
test of tomatoes, 433 
tests, purposes, 432 
Strains, disease resistant, 417 
Strawberry, breeding in America, 289, 294 
bud selection in, 398 
heterosis in, 364 
hybridization, 311, 398 
Strawberry Bush, see Spindle Tree. 
Stuart, bud selection, 394, 395 
potato, 428 
tuber-unit, 396, 397 
Sturtevant, crossing-over, factors that lower, 120, 
210 
Sturtevant and Bridges, crossing-over, 113 
no crossing-over in the male, 114 
Substitutional changes in factors, 267 
Sugar beet, 317 
INDEX 
Sugar beat, improvement begun, 291 
line selection, 340 
mass selection, 292, 340 
selection of mutations, 340, 370 
cane, heterosis in, 364 
Sumner, acquired characters, 491 
Sunflower, 317, 318 
chimeras, 381 
isolation of pure strains, 257 
red, 270 
self-sterile, 257 
Supernumerary legs in Drosophila, 136 
Surface, corn selection, 329, 330, 333 
linkage in oats, 125 
Surface and Barber, experimental error, 430 
oats, 429 
Surface and Pearl, soil heterogeneity, 431 
Surface and Zinn, oats, 340, 371 
planting board, 339 
record blanks, 435 
variations, 369 
Survival of the fittest, 5 
Sutton, plant breeding, 437 
plant improvements, 290 
Sval6f, method, 352 
-plant breeding station, 258, 293, 340 
system of breeding, 425 
Swedish, plant breeding station, 258 
Seed Association, 293 
Sweet pea, Blanche Ferry group, 309 
bush, 175, 308 
bush-Cupid, 176 
contabescence, 234 
collections, 299 
complementary factors, 140 
Cupid, 175, 177, 308 
diversity of variety, 303 
double, 307 
early flowering, 309 
first recorded hybrid, 309 
flower color in, 394 
form and size, 304 
habit in, 308 
history, 303, 304, 305 
hybridization and selection, 309 
linkage in, 125 
mutations in, 304 
novelty forms, 307 
origin of varieties, 303, 305 
snapdragon, 307 
species and varieties, 302 
tall and dwarf, 174, 175 
waved or Spencer, 306 
Swine, chromosome number, 537 
Hampshire, 476 
Mendelism in, 476 
mule footed, 476 
sex-deter mination in, 536 
spermatozoa in, 540 
white dominant in, 579 
Swingle, citrus, 297 
Synapsis, 61, 67, 108, 115, 121, 123, 199, 201, 204, 
559 
System, of aleurone color factors in maize, 163 
Digitized by Microsoft® 
