INDEX. 



455 



Sebright, Sir J., on crossed animals, 



15. 

 Sedgwick, Prof., on groups of species 



suddenly appearing, 282. 

 Seedlings destroyed by insects, 53. 

 Seeds, nutriment in, 60. 



, winged, 117. 

 , means of dissemination, 154, 



161, 327, 328. 



, power of resisting salt water, 



325. 

 , in crops and intestines of 



birds, 326, 327. 



, eaten by fish, 327, 346. 



in mud, 345. 



, hooked, on islands, 349. 



Selection of domestic products, 22. 

 , principle not of recent origin, 



27. 



, unconscious, 27. 



, natural, 62. 



, sexual, 69. 



, objections to term, 63. 



natural, has not induced ste- 

 rility, 247. 

 Sexes, relations of, 69. 

 Sexual characters variable, 123. 



selection, 69. 



Sheep, Merino, their selection, 23. 

 , two sub-breeds, unintentionally 



produced, 26. 



, mountain varieties of, 59. 



Shells, colours of, 107. 



, hinges of, 154. 



, littoral, seldom embedded, 270. 



— — , fresh-water, long retain the 



same forms, 308. 



, fresh-water, dispersal of, 344. 



, of Madeira, 349. 



, land, distribution of, 349. 



, land, resisting salt water, 325. 



Shrew-mouse, 373. 

 Silene, infertility of crosses, 243. 

 Silliman, Prof., on blind rat, 110. 

 Sirenia, their affinities, 302. 

 Sitaris, metamorphosis of, 394. 

 Skulls of young mammals, 159, 3S4. 

 Slave-making instinct, 216. 

 Smith, Col. Hamilton, on striped 



horses, 129. 

 ■ , Mr. Fred., on slave-making 



ants, 217. 



■ , on neuter ants, 231. 



Smitt, Dr., on the Polyzoa, 193. 



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's 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. 



, Herbert, Mr., on the first steps 



in differentiation, 100. 



, on the tendency to an equili- 

 brium 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 pedicellariae, 192. 



Sterility from changed conditions oi 

 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 habi ; s of cats. 209. 



Sting of bee, 163. 



Stocks, aboriginal, of domestic ani- 

 mals, 14. 



