_Arenga saccharifera_, 43 Argus-pheasant, wonderful plumage of, 205 Arums, 48 Assai of the Amazon, 43 Auckland Isles, handsome flowers of, 238 Audubon, on the ruby humming-birds, 130, 137 Australian Region, mammalia of, 340 birds of, 340 extinct fauna of, 341 its supposed union with S. America, 341 Azara, on food of humming-birds, 135 B. Bamboos, 52 uses of, 53-58 Bananas, wild, 47 Banana, 48 Barber, Mrs. on colour changes of pupa of _Papilio nireus_, 168 Barbets, 105 Bark, varieties of in tropical forests, 33 Barometer, range of, at Batavia, 24 Batavia, Meteorology of, 4 and London, diagram of mean temperatures, 5 greatest rainfall at, 24 range of barometer at, 24 Bates, Mr., on climate at the Equator, 24 on scarcity of forest-flowers on Amazon, 61 on animal life in Amazon valley, 70 on abundance of butterflies at Ega, 75 on importance of study of butterflies, 78 on leaf-cutting ants, 86 on blind ants, 88 on bird-catching spider, 97 on use of toucan’s bill, 106 on large serpents, 115 on the habits of humming-birds, 132 Bats, 118 Beetles, 94 abundance of, in New Forest-clearings, 96 probable use of horns of, 202 Belt, Mr., on virgin forests of Nicaragua, 62 on aspects of tropical vegetation, 67 on leaf-cutting ants, 86 on an Acacia inhabited by ants, 89 on uses of ants to the trees they live on, 90 on a leaf-like locust, 93 on tree-frogs, 116 on the habits of humming-birds, 133, 134 on uneatable bright-coloured frog, 175 on use of light of glow-worm, 205 Betel-nut, 45 Bill of humming-birds, 129 Biology, by-paths of, illustrated, 251 Birds, 99 how many known, 124 cases of local variation of colour among, 262 influence of locality on colours of, 255 which fertilize flowers, 273, 274 and insects blown to oceanic islands, 308 of Palæarctic Region, 316 of Ethiopian Region, 318 of Oriental Region, 320 Bonelli, Mr., on the Sappho comet humming-bird, 132 Bullock on food of humming-birds, 153 Buprestidæ, 94 Burchell, Dr., on the “stone mesembryanthemum,” 223 Butterflies, abundance of, in tropical forests, 72 conspicuousness of in tropical forests, 73 colours and form of, 74 peculiar habits of tropical, 76 tropical and temperate compared as to colour, 164 females do not choose their partners, 200 with gaily-coloured females, 204 numbers and variety of, 255 influence of locality on colours of, 255 Buttressed trees, 31 C. Calamus, 41 Callithea, imitated by species of Catagramma and Agrias, 257 _Callithea markii_, 75 _Campylopterus hemileucurus_, pugnacious and ornamental, 214 Cattleyas, 51 Cecropias, trees inhabited by ants, 89 Celebes, large and peculiarly formed butterflies of, 259 white-marked birds of, 263 Centipedes, 97