Edwards, Mr. W.H., on dark forms of Papilio turnus, 248
Eggs protectively coloured, 214, 215
theory of varied colours of, 216
Elaps mimicked by harmless snakes, 261
Embryonic development of man and other mammalia, 448
Ennis, Mr. John, on willows driving out watercresses from rivers of New Zealand, 24
Entomostraca, in bromelia leaves, 118
Environment never identical for two species, 149
direct action of, 418
direct influence of, 426
as initiator of variations, 436
action of, overpowered by natural selection, 437
Ethical aspect of the struggle for existence, 36
Euchelia jacobeæ inedible, 235
Everett, Mr. A., on a caterpillar resembling moss, 205
Evidence of evolution that may be expected among fossil forms, 380
Evolutionists, American school of, 420
Exogens, possible cause of sudden late appearance of, 400
External differences of man and apes, 453
Extinct animals, number of species of, 376
Extinction of large animals, cause of, 394
Eye, origin of, 130
Eyes, explanation of loss of in cave animals, 416
F
Facts of natural selection, summary of, 122
Falcons illustrating divergence, 108
and butcher birds, hooked and toothed beaks of, 422
Fantails, 91
Female birds, why often dull coloured, 277
Female birds, what their choice of mates is determined by, 286
butterflies, why dull coloured, 272
brighter than male bird, 281
choice a doubtful agent in selection, 283
preference neutralised by natural selection, 294
Fertility of domestic animals, 154
Flatfish, eyes of, 129
Flesh-fly, enormous increase of, 25
Floral structure, great differences of, in allied genera and species, 329
Flowers, variations of, 88
colours of, 308
with sham nectaries, 317
changing colour when fertilised, 317
adapted to bees or to butterflies, 318
contrasted colours of, at same season and locality, 318
fertilisation of, by birds, 319
self-fertilisation of, 321
once insect-fertilised now self-fertile, 323
how the struggle for existence acts among, 328
repeatedly modified during whole Tertiary period, 331
the product of insect agency, 332
Forbes, Mr. H.O., on protective colour of a pigeon, 200
on spider imitating birds' dropping, 211
Fossil shells, complete series of transitional forms of, 381
crocodiles afford evidence of evolution, 383
horses in America, 386
and living animals, local relations of, 391
Fowl, early domestication of, 97
Frill-back, Indian, 93
Frog inhabiting bromelia leaves, 118
Fruits, use of characters of, 133
colours of, 304
edible or attractive, 306
poisonous, 307
Fulica atra, protectively coloured eggs of, 215
Fulmar petrel, abundance of, 30
