458 



INDEX 



Stenoma schlaegeri, 245 



Sterility, 397 



Sterilization of defectives, 382 



Stings, of insects, 237; of honey-bee, 



238 

 Stomodaeum, 48 

 Struthiomimus, 153 

 Sturtevant, 314 

 Styela partita, eggs of, 302 

 Stylopid, 141 

 Subspecific forms, 21 

 Supplementary factors, 319 

 Survival of the fittest, 7, 386 

 Swammerdam, 8 

 Sweet peas, 319 

 Swimming legs, in bugs, 254 

 Symbiosis, 240 

 Symmetry, 34, 214 

 Symphalangism, 363 

 Synapsis, 292, 293 



Tail, in man, 87 



Tails, as weapons, 237 



Talpa europaea, 221 



Tar pan, 183 



Tatu novemcintus, 236 



Teeth, 82; abnormal growth in wood- 

 chuck, 212, 213; adaptations, 83; 

 adaptive radiation in, 253; develop- 

 ment of, 82; of beaver, 210; of 

 carnivores, 159, 233; of cynodonts, 

 157; of elephants, 168; heterodont 

 dentition, 159; of herbivores, 159; 

 of horse, 210; of mammals, 158; 

 and scales, 82; of squirrels, 210 



Termite, 271 



Termites, sj^mbiosis with protozoa, 

 240 



Terrestrial adaptations, 217 



Terrestrial life, demands upon verte- 

 brates, 148; forms transitional to, 

 148 



Tertiary, 122; climate, IGO; mam- 

 mals, 160; region of Bering Straits 

 during, 259 



Tetrad, 294; in Ascaris, 295 



Tetrakinetic theory, 434 



Tetralnphodon, 170, 172 



Thallophyta, 28 



Theophrastus, 5, 7 



Theories, adequate, conditions for, 

 429; Amphioxus, 144-146; An- 

 nelid, 144, 146; Arthropod, 144; 



Centroepigenesis, 424; coincident 

 selection, 408; chromosome, 289; 

 Darwinian, 385, 428; Germinal con- 

 tinuity, 422; germinal selection, 

 406; Goldschmidt's, 323; intra- 

 selection, 408; isolation, 409, 428; 

 kinetogenesis, 424; Lamarckian, 

 413; Mneme, 424; mosaic vision, 

 112; mutation, 402; natural selec- 

 tion, 385; origin of flight, 154; 

 pangenesis, 423; panmixia, 405; 

 sexual selection, 394; tetrakinetic, 

 434; use and disuse in chromo- 

 somes, 439 



Thymus, 94 



Thyroid, 94 



Tiger, sabre-tooth, 390; skull, 391 



Tiger-beetle, running leg, 218 



Tinamou, 244, 294 



Trapa nutans, leaves, 390 



Tree frogs, adhesive organs of, 233; 

 climbing, 223; flying, 229 



Triassic, 122; changes of climate, 248; 

 mollusca, 133 



Triceratops, 236 



Trihybrid, 279, 283, 284; in Guinea- 

 pig, 283; ratios, 284 



Trilobites, 134, 135 



Trilophodon, 169, 170; skull and 

 tooth, 174 



Trinacromenon, 153 



Trinil race, 199 



Triploblasts, 34 



Trout, 243 



Trunk, 166 



Tschermak, 276 



Tulips, 345 



Tusks, 167, 168, 174 



Ungulata, 164; cursorial, 219 

 Unguligrade appendage, 253 

 Unit characters, 279; and chromo- 

 somes, 303; and factors, 306; of 

 man, 361 

 Use and disuse, 414 



Variability, of organisms, 115; of 



environment, 116; cause and effect 



in, 117 

 Variation, 247; and natural selection, 



386 

 Variations, kinds of, 265; source of, 



269 



