of, 87

Arctic animals, supposed causes of white colour of, 191

Argyll, Duke of, on goose reared by a golden eagle, 75

Artemia salina and A. milhausenii, 426

Asclepias curassavica, spread of, 28

Asses running wild in Quito, 28

Attractive fruits, 306

Australia, spread of the Cape-weed in, 29
fossil and recent mammals of, 392

Azara, on cause of horses and cattle not running wild in Paraguay, 19

Azores, flora of, supports aerial transmission of seeds, 368

=B=

Baker, Mr. J.G., on rarity of spiny plants in Mauritius, 432

Ball, Mr., on cause of late appearance of exogens, 400

Barber, Mrs., on variable colouring of pupae of Papilio nireus, 197
on protective colours of African sun-birds, 200

Barbs, 91

Barriers, importance of, in questions of distribution, 341

Bates, Mr. H.W., on varieties of butterflies, 44
on inedibility of Heliconidae, 234
on a conspicuous caterpillar, 236
on mimicry, 240, 243, 249

Bathmism or growth-force, Cope on, 421

Beddard, Mr. F.E., variations of earthworms, 67
on plumes of bird of paradise, 292

Beech trees, aggressive in Denmark, 21

Beetle and wasp (figs.), 259

Beetle, fossil in coal measures of Silesia, 404

Beginnings of important organs, 128

Belt, Mr., on leaf-like locust, 203
on birds avoiding Heliconidae, 234

Belt's frog, 266

Birds, rate of increase of, 25
how destroyed, 26
variation among, 49
variation of markings of, 52
variation of wings and tails of, 53
diagram showing variation of tarsus and toes, 60
use of structural peculiarities of, 135
eggs, coloration of, 212
recognition marks of, 222
and butterflies, white in tropical islands, 230
sometimes seize inedible butterflies, 255
mimicry among, 263

Birds, sexual coloration of, 275
cause of dull colour of female, 277
choice of female not known to be determined by colour, etc., 285
decorative plumage of, 285
antics of unornamented, 287
which fertilise flowers, 319
colours of, not dependent on the colours of flowers, 336
no proof of aesthetic tastes in, 336
dispersal of, 355
and insects at sea, 357
of oceanic islands, 358
carrying seeds on their feet, 361
ancestral forms of, 407

Birthplace, probable, of man, 459

Bombyx regia, protective form of larva of, 210

Boyd Dawkins, on development of deer's horns, 389
on origin of man, 456

Brady, Mr. George, on protective colouring of starfishes, 209

Brain devel