484 
INDEX 
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 natu¬ 
ral selection, 437 
Ethical aspect of the struggle for 
existence, 36 
Euchelia jacobese inedible, 235 
Everett, Mr. A., on a caterpillar re¬ 
sembling 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 aud 
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 selec¬ 
tion, 283 
preference neutralis ed 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. 0., on protective 
colour of a pigeon, 200 
on spider imitating birds’ drop¬ 
ping, 211 
Fossil shells, complete series of transi¬ 
tional forms of, 381 
crocodiles afford evidence of 
evolution, 383 
horses in America, 386 
and living animals, local rela¬ 
tions 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 
