The Origin of Species by Means of Natural Selection · Charles Darwin
Conclusion, general, 421.
Sirenia, their affinities, 302. Sitaris, metamorphosis of, 394. Skulls of young mammals, 159, 384. Slave-making instinct, 216. Smith, Col. Hamilton, on striped horses, 129. Smith, Dr., on the Polyzoa, 193. Smith, Mr. Fred., on slave-making ants, 217. —, on neuter ants, 231. Snake with tooth for cutting through egg-shell, 214. Somerville, Lord, on selection of sheep, 23. Sorbus, grafts of, 246. Sorex, 373. Spaniel, King Charles’ breed, 25. Specialisation of organs, 98. Species, polymorphic, 35. —, dominant, 43. —, common, variable, 42. —, in large genera variable, 44. —, groups of, suddenly appearing, 282, 285. —, beneath Silurian formations, 287. —, successively appearing, 290. —, changing simultaneously throughout the world, 297. Spencer, Lord, on increase in size of cattle, 26. Spencer, Mr. Herbert, on the first steps in differentiation, 100. —, on the tendency to an equilibrium in all forces, 252. Sphex, parasitic, 216. Spiders, development of, 390. Sports in plants, 8. Sprengel, C.C., on crossing, 76. —, on ray-florets, 116. Squalodon, 302. Squirrels, gradations in structure, 139. Staffordshire, heath, changes in, 55. Stag-beetles, fighting, 69. Star fishes, eyes of, 144. —, their pedicellariæ, 192. Sterility from changed conditions of life, 7. —, of hybrids, 236. —, laws of, 241. —, causes of, 247. —, from unfavourable conditions, 250. —, not induced through natural selection, 247. St. Helena, productions of, 347.
St. Hilaire, Aug., on variability of certain plants, 174. —, on classification, 368. St. John, Mr., on habits of cats, 209. Sting of bee, 163. Stocks, aboriginal, of domestic animals, 14. Strata, thickness of, in Britain, 268, 269. Stripes on horses, 128. Structure, degrees of utility of, 159. Struggle for existence, 48. Succession, geological, 290. —, of types in same areas, 310. Swallow, one species supplanting another, 59. Swaysland, Mr., on earth adhering to the feet of migratory birds, 328. Swifts, nests of, 228. Swim-bladder, 148. Switzerland, lake habitations of, 13. System, natural, 364. Tail of giraffe, 157. —, of aquatic animals, 157. —, prehensile, 188. —, rudimentary, 400. Tanais, dimorphic, 36. Tarsi deficient, 108. Tausch, Dr., on umbelliferæ, 173. Teeth and hair correlated, 115. —, rudimentary, in embryonic calf, 397, 420. Tegetmeier, Mr., on cells of bees, 222, 226. Temminck, on distribution aiding classification, 369. Tendrils, their development, 196. Thompson, Sir W., on the age of the habitable world, 286. —, on the consolidation of the crust of the earth, 409. Thouin, on grafts, 246. Thrush, aquatic species of, 142. —, mocking, of the Galapagos, 356. —, young of, spotted, 388. —, nest of, 234. Thuret, M., on crossed fuci, 243. Thwaites, Mr., on acclimatisation, 112. Thylacinus, 374. Tierra del Fuego, dogs of, 211. —, plants of, 341. Timber-drift, 326.
Time, lapse of, 266. —, by itself not causing modification, 81. Titmouse, 141. Toads on islands, 350. Tobacco, crossed varieties of, 258. Tomes, Mr., on the distribution of bats, 351. Transitions in varieties rare, 134. Traquair, Dr., on flat-fish, 188. Trautschold, on intermediate varieties, 275. Trees on islands belong to peculiar orders, 350. —, with separated sexes, 78. Trifolium pratense, 57, 75. —, incarnatum, 75. Trigonia, 296. Trilobites, 286. —, sudden extinction of, 297. Trimen, Mr., on imitating-insects, 377. Trimorphism in plants, 35, 252. Troglodytes, 234. Tuco-tuco, blind, 110. Tumbler pigeons, habits of, hereditary, 210. —, young of, 392. Turkey-cock, tuft of hair on breast, 70. —, naked skin on head, 158. —, young of, instinctively wild, 265. Turnip and cabbage, analogous variations of, 125. Type, unity of, 166, 167. Types, succession of, in same areas, 310. Typotherium, 302. Udders enlarged by use, 8. —, rudimentary, 397. Ulex, young leaves of, 388. Umbelliferæ, flowers and seeds of, 116. —, outer and inner florets of, 173. Unity of type, 166, 167. Uria lacrymans, 72. Use, effects of, under domestication, 8. —, effects of, in a state of nature, 108. Utility, how far important in the construction of each part, 159. Valenciennes, on fresh-water fish, 344. Variability of mongrels and hybrids, 259. Variation, under domestication, 5. —, caused by reproductive system being affected by conditions of life, 7. —, under nature, 33. —, laws of, 106. —, correlated, 9, 114, 159.
Variations appear at corresponding ages, 10, 67. —, analogous in distinct species, 124. Varieties, natural, 32. —, struggle between, 59. —, domestic, extinction of, 86. —, transitional, rarity of, 134. —, when crossed, fertile, 257. —, when crossed, sterile, 256. —, classification of, 371. Verbascum, sterility of, 238. —, varieties of, crossed, 258. Verlot, M., on double stocks, 230. Verneuil, M. de, on the succession of species, 299. Vibracula of the Polyzoa, 193. Viola, small imperfect flowers of, 173. —, tricolor, 57. Virchow, on the structure of the crystalline lens, 145. Virginia, pigs of, 66. Volcanic islands, denudation of, 268. Vulture, naked skin on head, 158. Wading-birds, 375. Wagner, Dr., on Cecidomyia, 387. Wagner, Moritz, on the importance of isolation, 81. Wallace, Mr., on origin of species, 1. —, on the limit of variation under domestication, 31. —, on dimorphic lepidoptera, 36, 232. —, on races in the Malay Archipelago, 37. —, on the improvement of the eye, 145. —, on the walking-stick insect, 182. —, on laws of geographical distribution, 322. —, on the Malay Archipelago, 351. —, on mimetic animals, 377. Walsh, Mr. B.D., on phytophagic forms, 38. —, on equal variability, 125. Water, fresh, productions of, 343. Water-hen, 143. Waterhouse, Mr., on Australian marsupials, 90. —, on greatly developed parts being variable, 119. —, on the cells of bees, 220. —, on general affinities, 379.
Water-ouzel, 142. Watson, Mr. H.C., on range of varieties of British plants, 37, 46. —, on acclimatisation, 112. —, on flora of Azores, 328. —, on rarity of intermediate varieties, 136. —, on Alpine plants, 331. —, on convergence, 100. —, on the indefinite multiplication of species, 101. Weale, Mr., on locusts transporting seeds, 327. Web of feet in water-birds, 142. Weismann, Prof., on the causes of variability, 6. —, on rudimentary organs, 400. West Indian islands, mammals of, 352. Westwood, on species in large genera being closely allied to others, 45. —, on the tarsi of Engidæ, 124. —, on the antennæ of hymenopterous insects, 366. Whales, 182. Wheat, varieties of, 88. White Mountains, flora of, 330. Whittaker, Mr., on lines of escarpment, 267. Wichura, Max, on hybrids, 249, 251, 260. Wings, reduction of size, 109. —, of insects homologous with branchiæ, 148. —, rudimentary, in insects, 397. Wolf crossed with dog, 210. —, of Falkland Isles, 351. Wollaston, Mr., on varieties of insects, 38. —, on fossil varieties of shells in Madeira, 42. —, on colours of insects on sea-shore, 107. —, on wingless beetles, 109. —, on rarity of intermediate varieties, 136. —, on insular insects, 347. —, on land-shells of Madeira naturalised, 357. Wolves, varieties of, 71. Woodcock with earth attached to leg, 328. Woodpecker, habits of, 141. —, green colour of, 158.
Woodward, Mr., on the duration of specific forms, 276. —, on Pyrgoma, 284. —, on the continuous succession of genera, 293. —, on the succession of types, 311. World, species changing simultaneously throughout, 297. Wrens, nest of, 234. Wright, Mr. Chauncey, on the giraffe, 178. —, on abrupt modifications, 203. Wyman, Prof., on correlation of colour and effects of poison, 9. —, on the cells of the bee, 22. Youatt, Mr., on selection, 23. —, on sub-breeds of sheep, 26. —, on rudimentary horns in young cattle, 400. Zanthoxylon, 174. Zebra, stripes on, 128. Zeuglodon, 302.
Text from Project Gutenberg, public domain in the United States.