536 



INDEX. 



Temminck, on distribution aiding 



classification, 435, 

 Tendrils, their development, 232. 

 Thompson, Sir W., on the age of 



the habitable world, 338. 

 , on the consolidation of the 



crust of the earth, 482. 

 Thouin, on grafts, 290. 

 Thrush, aquatic species of, 169. 

 , mocking, of the Galapagos, 



421. 



, young of, spotted, 457. 



nest of, 276. 



Thuret, M., on crossed fuci, 287. 



Thwaites, Mr. , on acclimatization, 

 134. 



Thylacinus, 441. 



Tierra del Fuego, dogs of, 249. 



, plants of, 403. 



Timber-drift, 385. 



Time, lapse of, 314. 



, by itself not causing modi- 

 cation, 95. 



Titmouse, 168. 



Toads on islands, 413. 



Tobacco, crossed varieties of, 305. 



Tomes, Mr., on the distribution 

 of bats, 415. 



Transitions in varieties rare, 159. 



Traquair, Dr., on flat-fish, 222. 



Trautschold, on intermediate 

 varieties, 325. 



Trees on islands belong to pecul- 

 iar orders, 413. 



with separated sexes, 92. 



Trifolium pratense, 68, 88. 



— — incarnatum, 88. 



Trigonia, 351. 



Trilobites, 338. 



, sudden extinction of, 351. 



Trimen, Mr., on imitating-insects, 

 444. 



Trimorphism in plants, 42, 297. 



Troglodytes, 276. 



Tuco-tuco-blind, 130. 



Tumbler pigeons, habits of, he- 

 reditary, 248. 



Tumbler, young of, 462. 



Turkey-cock, tuft of hair on 

 breast, 83. 



, naked skin on head, 188. 



Turkey-cock, young of, instinct- 

 ively wild, 249. 



Turnip and cabbage, analogous 

 variations of, 149. 



Type, unity of, 197, 198. 



Types, succession of, in same 

 areas, 367. 



Typotherium, 357. 



Udders enlarged by use, 10. 



, rudimentary, 468. 



Ulex, young leaves of, 457. 



Umbelliferae, flowers and seeds 

 of, 138, 



, outer and inner florets of, 



205. 



Unity of type, 197, 198, 



Uria lacrymans, 85. 



Use, effects of, under domestica- 

 tion, 10. 



, effects of, in a state of 



nature, 128. 



Utility, how far important in the 

 construction of each part, 189. 



Valenciennes, on fresh- water fish, 



406. 

 Variability of mongrels and 



hybrids, 305. 

 Variation, under domestication, 7. 

 caused by reproductive sys 



tem being affected by conditions 



of Hfe, 8. 



under nature, 39. 



, laws of, 126. 



-, correlated, 10, 136, 189. 



Variations api^ear at correspond- 

 ing ages, 12, 79. 



analogous in distinct spe- 

 cies, 148. 



Varieties, natural, 37. 



, struggle between, 70. 



, domestic, extinction of, 101. 



, transitional, rarity of, 159. 



, when crossed, fertile, 301. 



Varieties, when crossed, sterile, 

 303. 



, classification of, 437. 



Verbascum, sterility of, 281. 



, varieties of, crossed, 304. 



Verlot, M., on doubl** stocks, 271. 



