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IVHUMMING-BIRDSAS ILLUSTEATING THE LUXURIANCE OF TROPICAL NATUREStructure Colours and Ornaments Descriptive Names The Motionsand Habits of Humming-birds Display of Ornaments by the MaleFood Nests Geographical Distribution and Variation Hummingbirdsof Juan Fernandez as illustrating Variation and Natural SelectionThe Relations and Affinities of Humming-birds How to Determinedoubtful Affinities Resemblances of Swifts and Humming-birdsDifferences between Sun-birds and Humming-birds Conclusion.THERE are now about ten thousand different kinds of birdsknown to naturalists, and these are classed in one hundredand thirty families, which vary greatly in extent, some containinga single species only, while others comprise manyhundreds. The two largest families are those of the warblers,with more than six hundred, and the finches with more thanfive hundred species, spread over the whole globe ;the hawksand the pigeons, also spread over the whole globe, numberabout three hundred and thirty and three hundred and sixtyspecies respectively while the diminutive ; humming-birds,confined to one hemisphere, consist of about four hundreddifferent species. They are thus, as regards the number ofdistinct kinds collected in a limited area, the most remarkableof all the families of birds. It may, however, very reasonablybe asked, whether the four hundred species of humming-birdsabove alluded to are really all distinct as distinct on theaverage as the ten thousand species of birds are from eachother. We reply that they certainly are perfectly distinctspecies, which never intermingle ;and their differences do notconsist in colour only, but in peculiarities of form, of structure,