Pyramid, the Great, 298 the Great, indicates an earlier civilization, 300 Pythons, 115 R. Rabbits, why white-tailed, 197 Rainbow, how described by ancient writers, 245 Rainfall at London and Batavia, diagram of, 15 Rainfall, greatest recorded at Batavia, 24 Ramsay, Prof. on ancient fresh-water deposits, 313 _Raphia tædigera_, 41 Rattan-palms, 42 Recognition aided by colour, 196 Reed, Mr., on humming-birds in Juan Fernandez, 146 Mr. Edwyn C., on insects of Juan Fernandez, 270 Reptiles, 111 Reptiles of oceanic islands, 309 Rhamphococcyx, 105 S. Salvin, Mr., on the pugnacity of humming-birds, 134, 214 Saüba ant, 85 _Saxifraga longifolia_, 233 _S. cotyledon_, 233 _S. oppositifolia_, 233 Scorpions, 97 Screw-pines, 49 Scythrops, 105 Seeds, how protected, 226 Sensitive-plants, 59 Sexes of butterflies differently coloured for recognition, 196 Sexual colours, 177 theory of, 192 Sexual selection not a cause of colour, 198 neutralized by natural selection, 210 Sickle-bill humming-bird, 136 Size, correspondence of, in tropical flowers and insects, 236 Sky, colour of not mentioned in old books, 245 Smith, Mr. Worthington, on mimicry in fungi, 223 Smyth, Professor Piazzi, on the Great Pyramid, 298 Snakes, 114 Sobralias, 51 Soil, heat of, 8 influence of temperature on climate, 8 Solenopsis, genus of ants, 84 Sorby, Mr., on composition of chlorophyll, 221 South America, extinct fauna of, 336 geographical changes of, 338 its parallelism with Africa, 339 an area of preservation of ancient types, 339 Spices from equatorial forest-trees, 36 Spiders, 97 Spruce, Dr. Richard, on number of ferns at Tarrapoto, 47 on inconspicuousness of tropical flowers, 61 on use of aromatic secretions of leaves, 278 Stainton, Mr., on insects attacking scented leaves, 277 Stick-insects, 92 St. Helena, indigenous flowers of, 275 St. John, Mr., on large python, 115 Structure of humming-birds, 125 Sugar from palm-trees, 44 Sunda Islands and Japan once joined to Asia, 326 Sun-birds, differences from humming-birds, 154 Sun’s noonday altitude in Java and London compared, 6 Sun’s rays, heating effect of, 7 Sunrise in the equatorial zone, 22 Swifts, resemblances of to humming-birds, 152 _Symmachia trochilus_, 75 _colubris_, 75 T. Tahiti, preponderance of ferns in, 269 Temperature of London and Batavia compared, 6 of different latitudes, various causes of, 7 Temperature, influenced by heat of soil, 8 influenced by aqueous vapour of atmosphere, 9 Temperature of tropical and temperate zones, cause of, illustrated, 12 Tertiary faunas and their relations, 344, 347 _Thaumastura cora_, very pugnacious, 214 Timor and Scotland, climates compared, 14 Timor and Flores, white-marked birds of, 263 Toucans, 106 Tree-frogs, 116