384 



INDEX. 



TrcchUium tipuliforme, 90. 



TROGONID.E, sexual colouring and 



. nidification of, 241. 



TROPICAL birds often green, 52. 



TROPICS, most favourable to pro- 

 duction of perfect adaptation 

 among animals, 68 ; not favour- 

 able to growth of civilization, 

 318. ' 



TROPIDORHYNCIIUS mimicked by 

 orioles, 104. 



TRUTHFULNESS of some savages, 

 353 ; not to be explained on 

 utilitarian hypothesis, 354. 



TURDID.E, sexual colouring and 

 nidification of, 245. 



TURNIX, 115, 251. 



TYNDALL, Professor, on origin of 

 consciousness, 361. 



TJPUPID^E, sexual colouring and 

 nidification of. 241. 



USEFUL and useless variations, 34. 



UTILITY, importance of the prin- 

 ciple of, 47, 127. 



VARIABILITY, simple, 144. 



VARIATIONS, useful and useless, 34; 

 laws of, 143, 266; as influenced 

 by locality, 166 ; of size, 168 ; 

 universality of, 287-291 ; are 

 there limits to, 291 ; of domestic 

 dogs, 293 ; of pigeons, 293. 



VARIETIES, instability of, supposed 

 to prove the permanent dis- 

 tinctness of species, 26; if su- 

 perior will extirpate original 

 species, 36; its reversion then 

 impossible, 37 ; of domesticated 

 animals may partially revert, 



38, 40; inconvenience of u<ing 



the term, 161. 



VERTEBRATA, mimicry among, 99. 

 VOICE of man, not explained by 



natural selection, 350. 

 VOLUCELLA, species of mimic bees, 



75, 98. 



WALSH. Mr., on dimorphism, of 

 Papilio turnus, 153. 



WEAPONS and tools, how they 

 affect man's progress, 314. 



WEEVILS often resemble small 

 lumps of earth, 58. 



WEIR, Mr. Jenner, on a moth 

 refused by birds, 89 ; on beetles 

 refused by birds, 93 ; on cater- 

 pillars eaten and rejected by 

 birds, 119. 



WESTWOOD, Professor, objections 

 to theory of mimicry, 108. 



WHITE colour in domesticated and 

 wild animals, 66. 



WILD and domesticated animals, 

 essential differences of, 38-41. 



WILL really exerts force, 357 ; 

 probably the primary source of 

 force, 368. 



WOOD, Mr. T. W., on orange-tip 

 butterfly, 59. 



WOODCOCKS and Snipes, protective 

 colouring of, 5'3. 



WOODPECKERS, why scarce in Eng- 

 land, 32. 



XANTHIA, autumnal colours of 

 these moths, 62. 



ZEBRAS, 299. 



