060 



INDEX 



lletcroaia in species hybrids, 233 



in trees, 365 



manifestations of, 353 



utilisation in corn, cucumber, tomato and 



tobacco, 362 



i n vegetatively propagated plants, 364 

 Heterosynapsis, 201, 204 ' 

 Heteroiygoais, and fertility, 559 



and hybrid vigor, 231 

 Heteroiygotes, contamination of factors in, 180 



number of, in Ft, 100 

 Heterozygous genotypes, 72 



number of kinds of, in Ft, 100 

 Heuer, Solanum chimera, 378 



Solatium grafts, 374 

 Hibiscus, dimorphic leaves, 275 

 Hinny, 517 



sterility of, 550 

 Hippeastrum, hybridised, 438 

 History of animal breeding, 443 



of plant breeding, 287 

 Hoffman, hybridization, 439 

 Hoge, Miss, reduplication of legs in Drosophila, 

 272 



supernumerary legs in Drosophila, 136 

 Homeosis due to mutilation, 269 

 Homeotic variations, 16 

 Homosynapsis, 201, 204 

 Homozygotes, number of, in Ft, 100 

 Homozygous genotypes, 72 



number of kinds, in FJ, 100 



of tobacco, 182 

 Honey bee, 26 



sex-determination, 210 

 Hops, heterosis in, 364 

 Hopkins, corn breeding experiments, 327 



maize, 293 



Hopkins and Smith, corn experiments, 328 

 Hormones and dimorphism, 276 

 Horse, American Standard bred, 484, 495, 574 



chromosome number in, 519, 537 



fertility in, 552 



history of modern, 460 



hybrids, 516, 528 



-quagga hybrids, 565 



secondary sexual characters in, 548 



sex-determination in, 536 



spermatozoa in, 541 



telegony, 565 



-zebra hybrids, 468, 520. 557, 567, 570 

 Horses, Arabian, 444, 460, 56C. 596 



Barbs, 444, 460 



coat color in, 465 



Clydesdale, 460, 461 



creating a gray breed, 470 



Danish, 444 



diversity of ancestry, 460 



Mendelism in, 465 



Percheron, 444, 460 



racing, 496 



Shetland, 460, 489 



Shire, 460 



Standard bred, 465, 467 



sterility in, 552 



Horses, Suffolk Punch. 460, 466 



Thoroughbreds, 461 



types of, 460 



white dominant in, 579 

 Horticultural practice, bud selection in, 391 

 Hoshino, linkage in peas, 125 

 Hover, prepotency, 574 

 Hovey, hybridization, 294 



plant breeding, 437 



strawberry, 289 

 Hume, peach, 297 

 Humming birds cross tobacco, 319 

 Huntington's chorea, 525 

 Hunt, timothy, 294 

 Hurst, horses, 465 



sweet pea, 310 

 Hutcheson, selection, 339 

 Hyacinth, improvement by Dutch, 288 



introduction, 287 



species and varieties, 302 

 Hyalodaphnia, 23 

 Hybrid, first plant, 438 



seed corn, producing, 361 

 Hybrids, aphis resistance in, 410 



cavy, 223 



forms of species, 227 



graft, 374, 382 



increased production in FI, 353 



intergeneric, 296 



intermediate expression in, 147 



interspecific, 296 



mosaic expression in, 152 



multif actor, 94 



Nicotiana, 228, 229 



(Enothera, 244 



sterility of, 556 



in species, 234, 236, 238 



superior qualities in Fi, 359 



utilization of, in breeding, 353 



variable character, expression in, 149 



vigor of species, 230 

 Hybridization, 11, 291, 294, 342 



and animal breeding, 508 



at Svalof, 425, 427 



begun by Knight, 288 



castration, 343 



choice of parents, 343 



conditions favorable for, 350 



difficulties in, 350 



extensive use, 311 



for disease resistance, 408 



future promise of, 294, 312, 316, 352 



general method, 343 



Goss and Mendel, 294 



harmful effects of, 571 



in apples, 295 



in birds, 521, 543 



in cattle, 473, 475, 520, 531. 533, 542 



in Coleus, 386, 389 



in cotton, 295 



in creating varieties, 302, 311 



in grain breeding, 294 



in guinea-pigs, 223, 235. 542 



in horses, 516, 528 



