Both, then, are birds of sober attire. Indeed of the two, the nightjar, with its soft and delicately pencilled plumage and the conspicuous white spots, is perhaps the handsomer, though, as it is seen only in the gloaming, its quiet beauty is but little appreciated. The unobtrusive dress of the nightingale, on the other hand, is familiar in districts in which the bird abounds, and is commonly quoted, by contrast with its unrivalled voice, as the converse of the gaudy colouring of raucous macaws and parrakeets. As has been said, both these birds are summer migrants, the nightingale arriving on our shores about the middle of April, the nightjar perhaps a fortnight later. Thenceforth, however, their programmes are wholly divergent, for, whereas the nightjars proceed to scatter over the length and breadth of Britain, penetrating even to Ireland in the west and as far north as the Hebrides, the nightingale stops far short of these extremes and leaves whole counties of England, as well as probably the whole of Scotland, and certainly the whole of Ireland, out of its calculations. It is however well known that its range is slowly but surely extending towards the west. This curiously restricted distribution of the nightingale, indeed, within the limits of its summer home is among the most remarkable of the many problems confronting the student of distribution, and successive ingenious but unconvincing attempts to explain its seeming eccentricity, or at any rate caprice, in the choice of its nesting range only make the confusion worse. Briefly, in spite of a number of doubtful and even suspicious reports of the bird's occurrence outside of these boundaries, it is generally agreed by the soundest observers that its travels do not extend much north of the city of York, or much west of a line drawn through Exeter and Birmingham. By way of complicating the argument, we know, on good authority, that the nightingale's range is equally peculiar elsewhere; and that, whereas it likewise shuns the departments in the extreme west of France, it occurs all over the Peninsula, a region extending considerably farther into the sunset than either Brittany or Cornwall, in both of which it is unknown. No satisfactory explanation of the little visitor's objection to Wild Wales or Cornwall has been found, and it may at once be stated that its capricious distribution cannot be accounted for by any known facts of soil, climate, or vegetation, since the surroundings which it finds suitable in Kent and Sussex are equally to be found down in the West Country, but fail to attract their share of nightingales.