550 



INDEX 



Saccharomyces 



chromosome maps of, 258 

 genetics and cytology of, 256-66 



Salmonella 



advantages for genetic studies, 268 

 recombination tests, 274-75 



5. typliimurium, genetic implications of mu- 

 tations in, 267-81 



Scales of measurement as related to domi- 

 nance, 313 

 Scaling tests, 162, 164, 174 

 Second-cycle hybrids, 453-54 



Secondary fertilization, 82, 90, 93 

 in angiosperms, 84 

 in flowering plants, 95 



Seed development, 104 



in angiosperms and gymnosperms, 81 



early stages of, 96 



without fertilization, 89-93 



grade and embryo growth potentialities, 



93-97 

 inbreeding and crossbreeding in, 81-97 



Seed in gymnosperms and angiosperms, 

 82-85 



Seed and embryo development, 103-5 



Seed size as related to embryo size and 

 heterosis, 103-4 



Seedling growth, 105 

 and heterosis, 105 



Seeds, number in maize X teosinte, 196 



Segregating factors, number of, 174 



Segregation, 24 



Segregation for yield factors, 382 



Segregations, irregular, 258 



Selecting for maximum heterosis, effective- 

 ness of methods, 339-51 

 Selection, 14, 161, 341, 406, 414 



for additive effects in normal distribution, 



355 

 for additive genetic values in individuals, 



359-61 

 for cross performance, 349 

 against a dominant deleterious mutant, 



220 

 effectiveness of, 333, 335 

 effectiveness of within inbred lines, 332- 



34 

 as an estimation problem, 354-58 

 when form of distribution is unspecified, 



355-58 

 for general and specific combining ability, 



353-54 

 for general combining ability, maternal 



ability, and specific ability' in line cross 



tests, 364-68 

 for general combining ability in topcross 



tests, 361-64 

 homozygous tester versus reciprocal, 



343-47 



index method, 355, 356 



on individual performance, 349 



ineffectiveness of, 335, 350 



by maximum likelihood estimates, 358-59 



natural and artificial, 219-20 



natural, for heterozygosity, 180-81 



performance levels attainable by, 341 



reciprocal or homozygous tester method, 



349 

 results of, 170 



for specific combinability, 454 

 on test-cross, 349 

 with unknown variances and covariances, 



358-59 

 use of all records in, 359 



Selection experiments, 156 

 controlled, 334-35 

 with swine, 350 



Selection for general and specific combining 

 ability, need for additional research, 

 369-70 



Selection within and among inbred prog- 

 enies, 401-2 



Selection of inbreds on performance, 140 



Selection index, 354 

 modified, 356 



Selection for maximum heterosis, methods 



of, 350-51 

 Selection, reciprocal, 351 



Selection, recurrent, 351 

 and early testing, 400-417 

 for maximum heterosis, 341-42 

 and overdominance, 451-73 



Selective advantage of a heterozygote, 467 



Selective advantage of polygenic characters, 



158 

 Self-fertiHzation, 16, 17, 45, 48, 139 



in alfalfa, 81 



versus cross-fertilization, 20 



in maize, 49 

 Self-fertilized populations, 322 

 Self-pollinated plants, 161 

 Self-pollinated and cross-pollinated plants, 

 comparison of methods, 55 



Selfed lines, first generation, 448 

 Selfing, 12, 16, 23, 173-74, 379, 382, 390, 

 402, 406, 409 



Selfing and crossing corn, results, 36 



Selfing and loss of vigor, 13 



Selfing series, 412-15 



Selfing and sibcrossing, comparison be- 

 tween, 41 



Semi-inbred lines in synthetics and h}-- 

 brids, utilization of, 431 



Senility, 14 



Sequential testing, 361 

 Shank, importance in modern corn breed- 

 ing, 146-17 



