378 



Index 



gastrulation and larva, 147 



half and three-quarter embryos, 

 224 



maturation, fertilization and 

 cleavage, 143, 148, 149 



posterior half-embryos, 226 

 SUMNER, effect of cold on mice, 246 

 Superman, 298, 299, 316 

 SWEDEN, extinct noble families, 312 

 Swine, wild and domestic, 264 

 SYMMETRY, 196, 109 

 Synapsis, 150, 154 

 Syndactylism, 69, 117 



Tadpoles, fed on thyroid, thymus, 



adrenal, 230 

 Talents, unused, 333 



parable of, 334 



Temperament, inheritance of, 71, 321 

 Temperature, influence on mutation, 



218 



influence on cell division, 217 

 TENEBRIO, sex differentiation in, 160 

 TENNENT, modified dominance in 



echinoderm hybrids, 105 

 Teratological characters inherited, 69 

 TERTULLIAN, 33 

 Tetrads, 153 

 THOMPSON, cross of yellow X green 



peas, 85 



diagram of Galton's 1st Law, 78 

 Thomsen's disease, 118 

 THORNDTKE, behavior of dogs, cats, 



monkeys, 48 

 "Thoroughbreds," 300 

 Thymus gland, fed to tadpoles, 230 

 Thyroid, effects on development, 233 



gland, fed to tadpoles, 230 

 Tissue cells, 7 

 Totipotence, of cleavage cells, 222, 



226, 236 

 Tower, action of selection, 267 



mutations in Leptinotarsa, 218, 



281 

 TOXOPNEUSTES, fertilization of egg, 



12 



Toyama, maternal inheritance, 113 

 Traducianism, 33 

 Training of animals, 51 

 Transmission hypothesis, 124 

 Trial and Error, 46 



Trihybrid, 95, 96 

 Triplets, hereditary, 68 

 Trophic correlations, 232 

 TROPISMS, 39, 42 



TSCHERMAK, rediscovery of "Men- 

 del's Law," 82 



Tuberculosis, inheritance of, 70 

 Turbellarian type of egg, 202 

 Twins, fraternal, 228 



hereditary, 68 



identical, 75, ^29, 252, 325 

 Ultra-microscopic units, 129 

 Uniqueness of every individual, 75, 



177 



UNIT CHARACTERS, 98, 100 

 UNITS OF LIVING MATTER, 129 



ultra microscopic, 129 



units of growth and division, 129 



units of heredity, 100-106, 129-131 

 Unity of organism, 55 

 Universal laws, 323 

 Use and disuse, effects of, 232 



effects not inherited, 237 

 Useful responses, 46 

 Uterus, attachment of oosperm to, 27 



Variability, caused by environment, 



280 

 Variations, 72 



continuous, 74 



discontinuous, 74 



fluctuations 74, 280 



meristic, 74 



mutations. 74, 280-286 



"sports," 74 

 Varied responses, 51 

 Vegetative pole of egg, n, 195 

 VIVIPARITY, 26 

 Viviparous development, 26 



WALTER, diagram of Galtonian in- 

 heritance, 73 

 filial regression, 80 



Wars, effects of, 303 



shake off social heredity, 256 



Wasserman test, 173 



WATASE, symmetry of egg of Lo- 

 ligo, 796 



WEEKS, 71 



Weidal test, 173 



WEISMANN, determinants and bio- 

 phores, 129 



