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