430 



INDEX. 



VARILTIES. 



T. 



Tail of giraffe, 147. 



of aquatic animals, 147. 



, prehensile, 176. 



, rudimentary, 376. 



Tanais, dimorphic, 33. 



Tarsi, deficient, 101 . 



Tausch, Dr., on umbelliferas, 162. 



Teeth and hair correlated, 107. 



, rudimentary, embryonic calf, 



373, 395. 



Tegetmeier, Mr., on cells of bees, 

 207, 211. 



Temminck, on distribution aiding 

 classification, 346. 



Tendrils, their development, 183. 



Thompon, Sir "W., on the age of the 

 habitable world, 268. 



, on the consolidation of the 



crust of the earth, 384. 



Thouin, on grafts, 230. 



Thrush, aquatic species of, 133. 



, mocking, of the Galapagos, 



335. 



, young of, spotted, 364. 



, nest of, 219. 



Thuret, M., on crossed fuci, 228. 



Thwaites, Mr., on acclimatisation, 

 105. 



Thylacinus, 351. 



Tierra del Fuego, dogs of, 197. 



, plants ot, 321. 



Timber, drift, 306. 



Time, lapse of, 249. 



by itself not causing modifica- 

 tion, 75. 



Titmouse, 132. 



Toads on islands, 329. 



Tobacco, crossed varieties of, 242. 



Tomes, Mr., on the distribution of 

 bats, 330. 



Transitions in varieties rare, 125. 



Traquair, Dr., on flat-fish, 175. 



Trautschold, on intermediate varie- 

 ties, 258. 



Trees on islands belong to peculiar 

 orders, 328. 



with separated sexes, 73. 



Trifolium pratense, 53, 69. 



incarnatum, 69. 



Trigonia, 278. 



Trilobites, 268. 



, sudden extinction of, 278. 



Trimen, Mr., on imitating-insects. 

 354. 



Trimorphism in plants, 33, 236. 

 Troglodytes, 219. 

 Tuco-tuco, blind, 102. 

 Tumbler-pigeons, habits of, heredi- 



tary, 196. 



Tumbler, young of, 368. 

 Turkey-cock, tuft of hair on breast, 



65. 



- , naked skin on head, 148. 



- , young of, instinctively wild, 

 197. 



Turnip and cabbage, analogous varia- 



tions of, 117. 

 Type, unity of, 156. 

 Types, succession of, in same areas, 



291. 

 Typotherium, 283. 



Udders enlarged by use, 8. 



- , rudimentary, 373. 

 Ulex, young leaves of, 364. 

 Umbelliferae, flowers and seeds of, 



108. 



- , outer and inner florets of, 161. 

 Unity of type, 156. 



Una lacrymans, 67. 

 Use, effects of, under domestication, 

 8. 



- , effects of, in a state of nature, 

 100. 



Utility, how far important in the 

 construction of each part, 149. 



V. 



Valenciennes, on fresh-water fish, 



323. 

 Variability of mongrels and hybrids, 



242. 



Variation under domestication, 5. 

 . caused by reproductive system 



being affected by conditions of life, 



6,7. 



- under nature, 30. 



- , laws of, 98. 



- , correlated, 8, 106, 149. 

 Variations appear at corresponding 



ages, 10, 62. 



- analogous in distinct species, 

 116. 



Varieties, natural, 30. 



- , struggle between, 65. 



- , domestic, extinction of, 80. 



- , transitional, rarity of, 125, 



