854 



INDEX 



Thuret, M., on crossed fuci, ii. 21 

 Thwiiites, Mr., on accliinatizatioa, i. 



200 

 Thylacinus (Tasmanian wolf), ii. 229 

 Tierra del Fuego, doga of, i. 355-366 



, plants of, ii. 177 



Timber, drift, ii. 153 

 Time, lapse of, ii. 57 

 by itaelf not causing modiflca- 



tion, i. 150 

 Titmouse (Piirus major), L 246 

 Toads on islands, ii. 191 

 Tobacco, crossed varieties of, ii. 44 

 Tomes, Mr., on the distribution of 



bats, ii. 193 

 Transitions in varieties rare, i. 234 

 Traquair, Dr., on flat-fish, i. 319 

 Trautschold, on intermediate varieties, 



ii. 72 

 Trees on islands belong to peculiar 



orders, ii. 191 



with separated sexes, i, 146 



Trifolium pratense, i. 113, 140 



repens, i. 113 



incarnatum, i. 140 



Trigonia, ii. 106 

 Trilobites, ii. 89 



, sudden extinction of, iu 107 



Trimen, Mr., on imitating-insects, ii. 



233 

 Trimorphism in plants, i. 78; ii. 35 

 Troglodytes, i. 392 

 Tucutuco, blind, i. 196 

 Tumbler pigeons, habits of, hereditary, 



i. 354 

 Tumbler, short-faced, young of, ii. 258 

 Turkey-cock, tuft of hair on breast, i. 



133 



, naked skin on head, i. 274 



, young of, instinctively wild, i. 



356 

 Turnip and cabbie, analogoas varia- 

 tions ot i- 220-221 

 Type, unity of, i. 286-287 



Types, succession of, in same areaa^ 



ii. 128 

 Typotherium, ii. 115 



U 



Udders enlarged by use, i. 36 



, rudimentary, ii. 265 



Dlex, young leaves of, ii. 251 



UmbellifersB, flowers and seeds of, i. 

 205-206 



, outer and inner florets of, L 



296-297 



Unity of type, L 286-287 



Uria lacrymans, i. 136 



Use, effects of, under domestication, 

 i. 36 



, effects of, in a state of nature, 



i. 193 



Utility, how far important in the con- 

 struction of each part, i. 275 



Valenciennes, on fresh-water fish, 



ii. 182 

 VariabiUty of mongrels and hybrids, 



ii. 46 

 Variation under domestication, i. 31 



caused by reproductive system 



being affected by conditions of life, 

 L 34 



under nature, i. 74 



, laws of, L 190 



, correlated, i. 37, 203, 274 



Variations appear at corresponding 

 ages, i. 39-40, 128 



analogous in distinct species, i. 



219 



Varieties, natural, L 73 



, stniggle between, i. 116 



, domestic, extinction of, L 158 



, transitional, rarity of, L 234 



, when crossed, fertile, it 40 



