532 



INDEX 



maturation, fertilization 

 and cleavage, 119, 120, 

 121 



posterior half-embryos, 320 

 Summation of Stimuli, 57 

 SUMNER, effect of cold on mice, 



349, 500 



Superman, 412, 439 

 SWEDEN, extinct noble families, 



436 



Swine, wild and domestic, 373 

 SYMMETRY, 168-170 

 Synapsis, 131 

 Syndactylism, 199, 293 



Tadpoles, fed on thyroid, thy- 



mus, adrenal, 326 

 Talents, unused, 471 



parable of, 473 

 Temperament, inheritance of, 



205, 291 



Temperature, influence on mu- 

 tation, 310 



influence on cell division, 



311 

 TENEBRIO, sex differentiation in, 



143 

 TENNENT, modified dominance 



in echinoderm hybrids, 267, 



500 



Teratological characters inheri- 

 ted, 199 

 TERTULLIAN, 41 

 Tetrads, 135 



THOMPSON, cross of yellow X 

 green peas, 229 



diagram of Gallon's 1st 



Law, 216, 495 

 Thomsen's disease, 295 

 THORNDIKE, behavior of dogs, 



cats, monkeys, 64, 495 

 "Thoroughbreds," 415 

 Thymus gland, fed to tadpoles, 



326 



Thyroid, effects on development, 

 331 



gland, fed to tadpoles, 326 



Totipotence, of cleavage cells, 



316, 318, 332 

 TOWER, action of selection, 379 



mutations in Leptinotarsa, 



310, 311, 348, 391 

 \ Traducianism, 41 

 Training of animals, 69 

 Transmission hypothesis, 91, 92 

 Treasury of Human Inheri- 

 tance, 294, 495 

 Trial and Error, 63 

 Trihybrid, 243, 244, ^5/381 

 Triplets, hereditary, 204 

 Trophic correlations, 329 

 TROPISMS, 52-56 

 TSCHERMAK, rediscovery of 



"Mendel's Law," 224 

 Tuberculosis, inheritance of, 



201, 202 



Turbellarian type of egg, 178 

 Twins, fraternal, 324 



hereditary, 204 



identical, 213, 323, 358, 457 



Ultra-microscopic units, 100 

 Uniqueness of every individual, 



155, 212, 213 



UNIT CHARACTERS, 250, 252, 253 

 UNITS OF LIVING MATTER, 97-102 



ultra microscopic, 100 



units of growth and di- 

 vision, 98, 99 



units of heredity, 99-102 

 Unity of organism, 46 

 Universal laws, 451 

 Use and disuse, effects of, 329 



effects not inherited, 339 

 Uterus, attachment of oosperm 



to, 31 



Variability, caused by environ- 

 ment, 388 



Variations, continuous, 210 

 discontinuous, 210 

 fluctuations, 211, 212 

 meristic, 210 

 mutations, 211, 212 

 "sports," 210 



