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

=G=

Gallinaceae, ornamental plumes of, 292

Galton, Mr. F., diagrams of variability used by, 74
on markings of zebra, 220 (note)
on regression towards mediocrity, 414
theory of heredity by, 443 (note)
on imperfect counting of the Damaras, 464

Gaudry on extinct animals at Pikermi, 377

Gay, Mons. T., on variations of structure in Cruciferae, 80

Gazella soemmerringi (figure), 219

Gazelles, recognition marks of, 218

Geddes, Professor, on variation in plants, 428
objection to theory of, 430

Geikie, Dr. Archibald, on formation of marine stratified rocks, 344

Geoffroy St. Hilaire, on species, 6

Geological evidences of evolution, 376, 381
record, causes of imperfection of, 379
distribution of insects, 403
antiquity of man, 455

Ghost-moth, colours of, 270

Glaciation, no proofs of, in Brazil, 370

Glow-worm, light a warning of inedibility, 287

Gomphia oleaefolia, variability of, 79

Goose eating flesh, 75