360 



Index 



Talents, unused, 315 



parable of, 316 

 Temperament, inheritance of, 71, 303 

 Temperature, influence on mutation, 

 210 

 influence on cell division, 209 

 Tenebrio, sex differentiation in, 159 

 Tennent, modified dominance in- 



echinoderm hybrids, 106 

 Teratological characters inherited, 69 

 Tertullian, 33 

 Tetrads, 154 



Thompson, cross of yellow X green 

 peas, 84 

 diagram of Gabon's 1st Law, 77 

 Tbomsen's disease, 118 

 Thorndike, behavior of dogs, cats, 



monkeys, 48 

 "Thoroughbreds," 283 

 Thymus gland, fed to tadpoles, 221 

 Thyroid, effects on development, 225 



gland, fed to tadpoles, 221 

 Tissue cells, 7 

 Totipotence, of cleavage cells, 213, 



215, 226 

 Tower, action of selection, 255 



mutations in Leptinotarsa, 210, 

 267 

 Toxopneustes, fertilization of egg, 



12 

 Toyama, maternal inheritance, 112 

 Traducianism, 33 

 Training of animals, 51 

 Transmission hypothesis, 124 

 Trial and Error, 46 

 Trihybrid, 92, 93, 95 

 Triplets, hereditary, 68 

 Trophic correlations, 224 

 Tropisms, 39, 42 



Tschermak, rediscovery of "Men- 

 del's Law," 81 

 Tuberculosis, inheritance of, 70 

 Turbellarian type of egg, 196 

 Twins, fraternal, 220 

 hereditary, 68 

 identical, 75, 220, 240, 309 



Ultra-microscopic units, 129 

 Uniqueness of every individual, 75, 



170 

 LTnit Characters, 97, 99 

 Units of living matter, 128 



ultra microscopic, 129 



units of growth and division, 129 



units of heredity, 99-104, 129-131 

 Unity of organism, 55 

 Universal laws, 305 

 Use and disuse, effects of, 223 



effects not inherited, 227 

 Useful responses, 46 

 Uterus, attachment of osperm to, 27 



Variability, caused by environment, 



266 

 Variations, 72 



continous, 74 



discontinuous, 74 



fluctuations, 74, 266 



meristic, 74 



mutations, 74, 262-270 



"sports," 74 

 Varied responses, 51 

 Vegetative pole of egg, 11, 190 

 Viviparity, 26 

 Viviparous development, 26 



Walter, diagram of Galtonian inheri- 

 tance, 73 

 filial regression, 79 

 Wars, effects of, 287 



shake off social heredity, 243 

 Wasserman test, 170 

 Watase, symmetry, of egg of Lo- 



ligo, 191 

 Weeks, 71 

 Weidal test, 170 



Weismann, determinants and bio- 

 phores, 129 

 germ plasm theory, 127, 130 

 hereditary and environmental 

 variations, 75 



on differential division of chro- 

 mosomes, 145, 199 

 inheritance of acquired charac- 

 ters, 226 

 nuclear control of differentia- 

 tion, 199 

 reduction of chromosomes, 156 

 What is Life?, 6 



Whitman, behavior of clepsine, 51 

 Necturus, 51 

 pigeons, 51, <,2 

 freedom and choice, 52, 53 

 sex of pigeons, 167 



