In conclusion, I would especially remark that the various changes in the outlines and mutual relations of our continents, which I have now endeavoured to establish, must not be supposed to have been all strictly contemporaneous. Some may have been a little earlier or a little later than others; some changes may have been slower, others more rapid; some may have had but a short duration, while others may have persisted through considerable geological periods. But, notwithstanding this uncertainty as to details, the great features of the geographical revolutions which I have indicated, appear to be established by a mass of concurring evidence; and the lesson they teach us is, that although almost the whole of what is now dry land has undoubtedly once lain deep beneath the waters of the ocean, yet such changes on a great scale are excessively slow and gradual; so that, when compared with the highest estimates of the antiquity of the human race, or even with that of most of the higher animals, our existing continents and oceans may be looked upon as permanent features of the earth’s surface. ERRATUM. At page 59 I have said that there are only three or four species of Mimosa which are sensitive. This is a mistake, as the greater portion of the species in the extensive genus Mimosa, as well as some species of several other genera of Leguminosæ, and also of Oxalidaceæ, possess this curious property. I cannot find, however, that any one has suggested in what way the sensitiveness may have been useful to the species which first acquired it. My guess at an explanation may therefore induce botanists who are acquainted with the various species in a state of nature, to suggest some better solution of the problem. INDEX. A. _Abrus precatoria_, perhaps a case of mimicry, 226 Absorption-colours or pigments, 183 Acræidæ, warning colours of, 174 Adaptive characters, 150, 155 Affinities, how to determine doubtful, 148 African large mammalia, recent immigrants, 323 Allen, Mr. Grant, on protective colours of fruits, 225 Alpine flowers, why so beautiful, 232 Amboyna, large-sized butterflies of, 258 American monkeys, 118 American Continents, past history of, 332 Ancient races of North and South America, 298 Andaman Islands, pale butterflies of, 260 white-marked birds of, 263 Anderson, Mr. W. Marshall, on cranium from N. American mound, 296 Andes, very rich in humming-birds, 139 Animal colours, how produced, 184 life in tropical forests, 70 Anthribidæ, 95 Ants, wasps, and bees, 80 numbers of, in India and Malaya, 81-88 destructive to insect-specimens, 85 and vegetation, special relation between, 89 Apatura and Heterochroa, resemblance of species of, 257 Apes, 116 Aqueous vapour of atmosphere, its influence on temperature, 9 quantity at Batavia and Clifton, 10 Arctic plants, large leaves of, 236 flowers and fruits brightly coloured, 237 Areca palm, 45