INDEX 



PAGE 



Species, nature of, chapter on 112-123 



origin of, conditions governing 6-7 



uncertainty in defining 115-116 



Spectroscope, revelations made by 361-362 



Spencer, Herbert, cited 113, 115, 116, 117, 352 



Spirit of the hive, reference to 193 



Spirogyra, modes of reproduction ,of 146 



"Splitters" (a school of naturalists), reference to 115 



Spore-bearing leaf of cycad, figure shovi'ing 146 



Stegodon, features of 236-237 



form of head and molar teeth of 239 



Stensio, fossils collected by 273-274 



Stewart, Charles, cited 177 



Stingless bee, form and habits of 199-200 



Strong, O. S., and Hubbard, J. G., figure made from photograph by. . . 218 



Structure and function, coordination of 67-68 



Struggle for existence, reference to 20 



Suns, evolution of 355-357 



Survival of the fittest, limits of operation of 7 



Swarm of bees, figure showing 188 



Talgai, Queensland, Australia, fossil skull from 134-135 



Teeth, derivation of 175-176 



Teeth of apes and monkeys, features of 44 



Teeth of man, vestigial elements in 44-45 



Tenrec, reference to 287 



Tertiary period, animals of, in North and South America 88-91 



apes of, features of skulls of 133 



climate of 86 



deer of 132 



events of I6l 



mammals of 128-129 



uplift of Isthmus of Panama in 89, 91 



Texas, ant from, figure showing 220 



remains of theromorphs from 282 



Theophrastus, classification of plants by 139-140 



Theory, definition and character of 143-144 



Theromorphs, features of 282-284 



reference to 281 



"Thinking wishly," causes of 9 



Thinopus, footprint of 2 59 



Thomson, J. Arthur, chapter by 13-23 



cited 187 



Tilney, cited 289 



Time table showing geological ages and periods 161 



Tortoises of Galapagos Islands, reference to 15-16 



Townsend piper, view of 253 



Tree ants, nests of, figure showing 222 



Tree frog, embryonic and larval stages in 55-56 



Tree of life, illustration symbolizing Frontispiece 



Triassic period, events of 161 



fishes of 130 



[390] 



