492 



INDEX 



Species, which vary little, 80 



closely allied inhabit distinct 



areas, 111 

 vigour and fertility of, how kept 

 up, 327 

 Spencer, Mr. Herbert, on factors of 

 organic evolution, 411 

 on effects of disuse, 413 

 on difficulty as to co-adaptation 



of i)arts, 417 

 on direct action of environment, 

 418 

 Sphingidae, protective attitudes of 



larvte, 210 

 Sphinx ligustri, general resemblance 



of larva to food plant, 202 

 Spider, alluriug coloration of, 211 

 Spines, on origin of, 431 



rarity of, in oceanic islands, 432 

 Spiny plants abundant in South Africa 



and Chile, 433 

 Sj)ots a primitive ornamentation of 



animals, 289 

 Sprengel on flowers and insects, 309 

 Staphylinidoe, protective habit of, 



210 

 Sterility of mongrels, 165 



correlated with colour, etc., 168 

 and natural selection, 173 

 of hybrids produced by natural 

 selection, 179 

 Struggle for existence, 14 

 among plants, 15 

 for life, illustrations of, 1 8 

 for existence on the pampas, 22 

 for life between closely allied 



forms most severe, 33 

 for existence, ethics of, 36 

 how it acts among flowers, 328 

 Summary of facts of colouring for 

 protection and recognition, 

 227 

 Survival of the fittest, 11, 122, 123 

 Swaiuson, definition of species, 2 

 Swamping effects of intercrossing, 



142 

 Sweden, destruction of grass by larvae 



of moths in, 17 

 Swiuhoe, Mr., on protective colouring 



of a bat, 201 

 Symmetry, bilateral in colours of 

 animals needful for recogni- 

 tion, 217 



Tails used as respirators, 136 



Tapirs, distribution of, 352 



Tegetmeier, Mr., on feeding habits of 

 jjigeons and fowls, 75 

 on sparrows and crocuses, 75 

 - on curious correlations in 

 pigeons, 140 



Tegumeutary appendages and colour, 

 291 



Thousand-fathom line divides oceanic 

 from continental islands, 347 

 the teachings of, 348 

 map showing, 349 



Thwaites, Mr., on spread of Lantana 

 mixta in Ceylon, 30 



Tiger, use of stripes of, 199 



Titmice as illustrating divergence, 

 107 



Transformation of species of Crustacea, 

 427 



Transmutationists, the early, 3 



Travers, Mr. W. L. , on effects of in- 

 troduced j^lauts in New Zea- 

 land, 29 



Trees, great variety of, in many 

 forests, 36 



Trimen, Mr., on butterfly deceived by 

 its mimic, 245 

 on mimicry, 247 



Tropical animals, why brilliantly 

 coloured, 299 



Tropics, no proof of lower tempera- 

 ture of, 369 



'rroi")idorhynchi mimicked by orioles, 

 263 



Trumpeter, 93 



Tumblers, 91 



Turbits and owls, 91 



Tylor, Mr. A., on Coloration in Ani- 

 mals and Plants, 285 



U 



Ungulates, origin of feet of, 423 

 Use and disuse, effects of, overjiowered 



by natural selection, 435 

 Useless characters, 131 

 not specific, 132 



