Chapter D: Danaidæ, warning colours of, 174

Danainæ, Acræinæ and Heliconiinæ, local resemblances of, 256

_Daphne pontica_, 230

Darwin, Mr., on mode of cross-fertilization and its use, 228
not too highly rated, 252
on vegetation of Galapagos, 272
on use of scented leaves, 277
on former union of West Indian islands and S. America, 306
on oceanic islands, 307
revolution in thought effected by, 284

Deserts on line of tropics, 28

_Desmoncus_, 41

De Vry, Mr., on the sugar-palm, 43

Dews, cause of heavy tropical, 10

Diagram of mean temperature at Batavia and London, 5
of rainfall at Batavia and London, 15

_Dianthus alpinus_, _D. glacialis_, 232

Distribution of humming-birds, 138

Dragons or flying-lizards, 113

Drugs from equatorial forest-trees, 36

Duke-of-York Island, pale-coloured insects of, 259
Islands, remarkable white plumaged birds of, 263

Dyes from equatorial forest-trees, 36

Dynastidæ, 95
probable use of horns of, 202

E.

Earl, Mr. George Windsor, on division of Malay Archipelago, 307

Earth-sculpture or surface-geology, 250

Earthworks, North American, 292

Easter Island, sculptures on, 291

Eciton, genus of foraging ants, 87

Elateridæ, luminous species perhaps mimetic, 205

Emperor-moth, protective coloration of, 174

Environment, relation of living things to, 254

_Epicalia_, sexes of, differently coloured, 178

_Epilobium angustifolium_, _E. parviflorum_, 233

Epimachinæ, 150

Equator, cause of uniform high temperature near, 6
short twilight at, 21

Equatorial climate, general features of, 17
uniformity of in all parts of the world, 18
local diversities of, 19

Equatorial forests, general features of, 29

Equatorial forest-belt, cause of, 27

Equatorial heavens, aspect of, 23

Equatorial zone, temperature of, 3

Ethiopian Region, 317

_Eugenes fulgens_, 134

Eunica and Siderone, resemblance of species of, 257

Euplœa, pale species of, in Moluccas and New Guinea, 258

Euro-Asiatic continent, Miocene fauna of, 323

Eustephanus, 141

_Eustephanus galeritus_, 143

_Euterpe oleracea_, 43

Evaporation and condensation, equalising effects of, 16

F.

Female birds, greater brilliancy of some, 211

Female insects, greater brilliancy of some, 203

Ferns, 46

Ferns, preponderance of in Tahiti and Juan Fernandez, 269, 270

Fiji Islands, pale butterflies of, 259

Fire-ants, 83

Fishes, causes of general coloration of, 171

Flowering trunks, probable cause of, 34

Flowers, comparative scarcity of in equatorial forests, 60

Flowers and insects, 64

Flowers of temperate zones brilliantly coloured, 165
comparatively scarce in tropical forests, 167

Flowers, attractive colours of, 228
fertilized by insects, 228
attractive odours of, 230
when sweet-scented not conspicuously coloured, 230
attractive grouping of, 231
alpine, why so beautiful, 232
why allied species differ in beauty, 233
when wind-fertilized not coloured, 233
relation of colours of, to distribution, 235
and fruits, recent views as to action of light on, 236

Flowers of Auckland and Campbell’s Isles, bright-coloured, 238

Flying-lizards, 113

Foliage, two chief types of, in tropical forests, 33
colours of, 221

Foot of savages does not approach that of apes, 289 (note)

Forest-belt, cause of equatorial, 27

Forest-belts, temperate, 29

Forest-tree, section of a Bornean, 32
formed from climbers, 32

Forest-trees, characteristics of, 30

Forest-trees of low growth, 34

Forest-trees, uses of equatorial, 35

Forests, effect of on rainfall and drought, 19
devastation caused by destruction of, 20
equatorial, 29
undergrowth of tropical, 34

_Formica gigas_, 81

Foxes, none in Isle of Wight in 1605, 305

Frogs and toads, 116

Frog, with bright colours uneatable, 175

Frogs of oceanic islands, 309

Fruit-bats, 119

Fruits of equatorial forest-trees, 36

Fruits, attractive colours of, 224
protective colours of, 225
greater antiquity of protected than attractive, 227

G.

Galapagos, colours of productions of, 163
poor in flowers and insects, 235
weedy vegetation of, 272

Gardner, Dr., on a large water-boa, 115

Geckos, 112

Geiger, on ancient perception of colour, 245

_Geranium pratense_, _G. pusillum_, 233

Gibbons, 116

Ginger-worts, 47

Gladstone, Mr., on the colour-sense, 245

Glow-worm, use of its light, 205

Goliath cuckoo, 105

Gosse, Mr., on Jamaica humming-birds, 132, 135
on the pugnacity of humming-birds, 134
on food of humming-birds, 137

Gould, Mr., on the motions of humming-birds, 131

Grammatophyllums, 51

Green, why the most agreeable colour, 244

Grisebach, on cause of vivid colours of arctic flowers, 237

_Guilielma speciosa_, 42

Gums from equatorial forest-trees, 36

H.

_Habenaria chlorantha_, 230

Habits of humming-birds, 130

Heat due to condensation of atmospheric vapour, 14
changes colours, 183

Heliconiinæ and Acræinæ, local resemblances of, 256

Hindostan and Africa, resemblances of fauna of, 328

Hooker, Sir J. on flowers of Auckland Isles, 238
on deficient odour of New Zealand flowers, 277

Hornbills, 107

Horns of beetles, probable use of, 202

Howling-monkeys, 118

Humming-birds, number of, 124, 133
distinctness of, 125, 129
structure of, 125
colours and ornaments of, 127
descriptive names of, 129
motions and habits of, 130
display of ornaments by males, 134
food of, 135
nests of, 137
geographical distribution and variation of, 138
of Juan Fernandez, 140
influenced by varied conditions in South America, 147
relations and affinities of, 148
sternum of, 151
eggs of, 152
feather-tracts of, 152
resemblance of swifts to, 152
nestlings of, 153
differences from sun-birds, 154