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Rh to, by modern writers, for not one of these professes to have arrived at any final, but only a provisional, arrangement; it seems, however, expedient to notice the fact that some of the authors of the 18th century supposed themselves to have seen the way to dividing what we now know as the family Trochilidae into two groups, the distinction between which was that in the one the bill was arched and in the other straight, since that difference has been insisted on in many works. This was especially the view taken by Brisson and Buffon, who termed the birds having the arched bill “colibris,” and those having it straight “oiseaux-mouches.” The distinction wholly breaks down, not merely because there are Trochilidae which possess almost every gradation of decurvation of the bill, but some which have the bill upturned after the manner of that strange bird the avocet, while it may be remarked that several of the species placed by those authorities among the “colibris” are not humming-birds at all.

In describing the extraordinary brilliant plumage which most of the Trochilidae exhibit, ornithologists have been compelled to adopt the vocabulary of the jeweller in order to give an idea of the indescribable radiance that so often breaks forth from some part or other of the investments of these feathered gems. In all, save a few other birds, the most imaginative writer sees gleams which he may adequately designate metallic, from their resemblance to burnished gold, bronze, copper or steel, but such similitudes wholly fail when he has to do with the Trochilidae, and there is hardly a precious stone—ruby, amethyst, sapphire, emerald or topaz—the name of which may not fitly, and without any exaggeration, be employed in regard to humming-birds. In some cases this radiance beams from the brow, in some it glows from the throat, in others it shines from the tail-coverts, in others it sparkles from the tip only of elongated feathers that crest the head or surround the neck as with a frill, while again in others it may appear as a luminous streak across the cheek or auriculars. The feathers that cover the upper parts of the body very frequently have a metallic lustre of golden-green, which in other birds would be thought sufficiently beautiful, but in the Trochilidae its sheen is overpowered by the almost dazzling splendour that radiates from the spots where Nature’s lapidary has set her jewels. The flight feathers are almost invariably dusky—the rapidity of their movement would, perhaps, render any display of colour ineffective: while, on the contrary, the feathers of the tail, which, as the bird hovers over its food-bearing flowers, is almost always expanded, and is therefore comparatively motionless, often exhibit a rich translucency, as of stained glass, but iridescent in a manner that no stained glass ever is—cinnamon merging into crimson, crimson changing to purple, purple to violet, and so to indigo and bottle-green. But this part of the humming-bird is subject to quite as much modification in form as in colour, though always consisting of ten rectrices. It may be nearly square, or at least but slightly rounded, or wedge-shaped with the middle quills prolonged beyond the rest; or, again, it may be deeply forked, sometimes by the overgrowth of one or more of the intermediate pairs, but most generally by the development of the outer pair. In the last case the lateral feathers may be either broadly webbed to their tip or acuminate, or again, in some forms, may lessen to the filiform shaft, and suddenly enlarge into a terminal spatulation as in the forms known as “racquet tails.” The wings do not offer so much variation; still there are a few groups in which diversities occur that require notice. The primaries are invariably ten in number, the outermost being the longest, except in the single instance of Aithurus, where it is shorter than the next. The group known as “sabre-wings,” comprising the genera Campylopterus, Eupetomena and Sphenoproctus, present a most curious sexual peculiarity, for while the female has nothing remarkable in the form of the wing, in the male the shaft of two or three of the outer primaries is dilated proximally, and bowed near the middle in a manner almost unique among birds. The feet again, diminutive as they are, are very diversified in form. In most the tarsus is bare, but in some groups, as Eriocnemis, it is clothed with tufts of the most delicate down, sometimes black, sometimes buff, but more often of a snowy whiteness. In some the toes are weak, nearly equal in length, and furnished with small rounded nails; in others they are largely developed, and armed with long and sharp claws.

Apart from the well-known brilliancy of plumage, of which enough has been here said, many humming-birds display a large amount of ornamentation in the addition to their attire of crests of various shape and size, elongated ear-tufts, projecting neck-frills, and pendant beards—forked or forming a single point. But it would be impossible here to dwell on a tenth of these beautiful modifications, each of which as it comes to our knowledge excites fresh surprise and exemplifies the ancient adage—maxime miranda in minimis Natura. It must be remarked, however, that there are certain forms which possess little or no brilliant colouring at all, but, as most tropical birds go, are very soberly clad. These are known to trochilidists as “hermits,” and by Gould have been separated as a subfamily under the name of Phaethornithinae, though Elliot says he cannot find any characters to distinguish it from the Trochilidae proper. But sight is not the only sense that is affected by humming-birds. The large species known as Pterophanes temmincki has a strong musky odour, very similar to that given off by the petrels, though, so far as appears to be known, that is the only one of them that possesses this property.

All well-informed people are aware that the Trochilidae are a family peculiar to America and its islands, but one of the commonest of common errors is the belief that humming-birds are found in Africa and India—to say nothing even of England. In the first two cases the mistake arises from confounding them with some of the brightly-coloured sun-birds (Nectariniidae), to which British colonists or residents are apt to apply the better-known name; but in the last it can be only due to the want of perception which disables the observer from distinguishing between a bird and an insect—the object seen being a hawk-moth (Macroglossa), whose mode of feeding and rapid flight certainly bears some resemblance to that of the Trochilidae, and hence one of the species (M. stellarum) is very generally called the “humming-bird hawk-moth.” But though confined to the New World the Trochilidae pervade almost every part of it. In the south Eustephanus galeritus has been seen flitting about the fuchsias of Tierra del Fuego in a snow-storm, and in the north-west Selatophorus rufus in summer visits the ribes-blossoms of Sitka, while in the north-east Trochilus colubris charms the vision of Canadians as it poises itself over the althaea-bushes in their gardens, and extends its range at least so far as lat. 57° N. Nor is the distribution of humming-birds limited to a horizontal direction only, it rises also vertically. Oreotrochilus chimborazo and O. pichincha live on the lofty mountains whence each takes its specific name, but just beneath the line of perpetual snow, at an elevation of some 16,000 ft., dwelling in a world of almost constant hall, sleet and rain, and-feeding on the insects which resort to the indigenous flowering plants, while other peaks, only inferior to these in height, are no less frequented by one or more species. Peru and Bolivia produce some of the most splendid of the family—the genera Cometes, Diphlogaena and Thaumastura, whose very names indicate the glories of their bearers. The comparatively gigantic Patagona inhabits the west coast of South America, while the isolated rocks of Juan Fernandez not only afford a home to the Eustephanus but also to two other species of the same genus which are not found elsewhere. The slopes of the Northern Andes and the hill country of Colombia furnish perhaps the greatest number of forms, and some of the most beautiful, but leaving that great range, we part company with the largest and most gorgeously arrayed species, and their number dwindles as we approach the eastern coast. Still there are many brilliant humming-birds common enough in the Brazils, Guiana and Venezuela. The Chrysolampis mosquitus is perhaps the most plentiful. Thousands of its skins are annually sent to Europe to be used in the manufacture of ornaments, its rich ruby-and-topaz glow rendering it one of the most beautiful objects imaginable. In the darkest depths of the Brazilian forests dwell the russet-clothed brotherhood of the genus Phaethornis—the “hermits”; but the great wooded basin of the Amazons seems to be particularly unfavourable to the Trochilidae, and from Pará to Ega there are scarcely a dozen species to be met with. There is no island of the Antilles but is inhabited by one or more humming-birds, and there are some very remarkable singularities of geographical distribution to be found. Northwards from Panama the highlands present many genera whose names it would be useless here to insert, few or none of which are found in South America—though that must unquestionably be deemed the metropolis of the family—and advancing towards Mexico the numbers gradually fall off. Eleven species have been enrolled among the fauna of the United States, but some on slender evidence, while others only just cross the frontier line.

The habits of humming-birds have been ably treated by writers like Waterton, Wilson and Audubon, to say nothing of P. H. Gosse, A. R. Wallace, H. W. Bates and others. But there is no one appreciative