384 
Trochilium tipuliforme, 90. 
Troconip#, sexual colouring and 
nidification of, 241. 
Tropicat birds often green, 52. 
Trorics, most favourable to pro- 
duction of perfect adaptation 
among animals, 68 ; not favour- 
able to growth of civilization, 
318. 
Tropipornyncuus mimicked by 
orioles, 104. 
TRUTHFULNESS of some savages, 
353; not to be explained on 
utilitarian hypothesis, 354. 
Turpipe, sexual colouring and 
nidification of, 245. 
Turnrx, 115, 251. 
Tynpaut, Professor, on origin of 
consciousness, 361. 
UPUPIDA, sexual colouring and 
nidification of, 241. 
Usrrvx and useless variations, 34, 
Unity, importance of the prin- 
ciple of, 47, 127. 
VARIABILITY, simple, 144. 
Variations, useful and useless, 84; 
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, 
Vanierizs, 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, 
INDEX. 
88, 40; inconvenience of using 
the term, 161. 
Verresrata, mimicry among, 99. 
Voice of man, not explained by 
natural selection, 350. 
Vouuce.ua, species of mimic bees, 
75, 98, 
WALSH, Mr., on dimorphism, of 
Papilio turnus, 153. 
Wearons and tools, how they 
affect man’s progress, 314. 
Weevits 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 
Westwoop, Professor, objections 
to theory of mimicry, 108. 
Wire colour in domesticated and 
wild animals, 66. 
Wixp and domesticated animals, 
essential differences of, 38-41. 
Witt really exerts force, 367; 
probably the primary source of 
force, 368. 
Woop, Mr. T. W., on orange-tip 
butterfly, 59. 
Woopcocxs and Snipes, protective 
colouring of, 53. 
Woopreckers, why scarce in Eng- 
land, 32. 1 
XANTHIA, autumnal colours of 
these moths, 62, 
ZEBRAS, 299, 
