some of the more powerful eagles (Haliatus leucocephalus, SAVIGNY, &c.) will pursue their congeners and force them to surrender the prey they may have

caught, yet we are not aware of any recorded instance of one eagle making prey of another, as spiders are known to do, and as is common among fish. On the contrary, the males and females of birds of prey appear to be more closely attached than those of most other species. They continue together not only during the breeding season, but throughout the year, and even for a long succession of years, at least if we may trust to the circumstantial evidence of a pair of eagles frequenting the same locality, and building on the same spot.

The evidence indeed for the birds being always the same is incomplete; yet on the supposition that it is not the same but successive pairs which are observed in the same place, we are led to the curious inquiry how the death or disappearance of one pair is supplied by another. We have in more than one instance observed a pair of magpies nestle on the same tree for a series of years, where they reared a brood of four or five young ones every season. All of these disappeared from the neighbourhood,—at least we observed no increase in the number of nests. In one instance we observed a magpie's nest thus successively occupied for ten years.* The number of young, therefore, annually reared in such an hereditary nest, as it may well be called, must be nearly proportional to the supply of the mortality among these birds either from accident or disease. Should the female, for instance, which has just reared a brood, be accidentally killed, the male must either seek for another partner or abandon the nest to some of his descendants. That the former is the usual manner of proceeding, will appear from facts which we shall immediately state; but that the latter may also occur may be inferred from the young birds, upon leaving their parents, establishing

* J. R.

themselves, as they must do, in the best situation they can discover.

The continuance of a nest in the same spot for several years is more remarkable in the case of migratory birds than in that of magpies, which do not migrate, and seldom go to any considerable distance from their breeding trees. There has been in a garden adjacent to ours, the nest of a black-cap (Sylvia atricapilla) for a succession of years, and broods have been successively reared there, without any observable increase in the population of the species. Yet this bird, which is little bigger than a wren, weighing only half an ounce, has to traverse annually the whole of the south of Europe, and probably a great proportion of the north of Africa, exposed of course to numerous accidents, as well as to occasional scarcity of its appropriate food. From the regular annual restoration, however, of this nest at the same spot, it is obvious that one, if not both of

the black-caps, must have been wont to perform this extensive migration to and from Africa as safely as the more hardy cuckoo or the more swift-winged swallow. During the spring of 1831, the black-caps, which we suppose to be the same birds, from their keeping to the same place of nestling, were more than usually late in arriving; for in another garden about a mile off, there were young in the hereditary nest of black-caps before our little neighbours made their appearance from the South. When they did arrive, their attention was immediately attracted by the unusual circumstance of hearing the loud song of a rival in the vicinity of their premises. This was a cock black-cap, which we had purchased the preceding autumn in the bird-market at Paris, and which was daily hung out in his cage to enjoy the fresh air and the sunshine, within a gun-shot of their usual place of nestling. The wild birds did not appear to like the little stranger at all; and the cock kept flying around the cage, alternately exhibiting curiosity, fear, anger, defiance, and triumphant exultation. Sometimes he would flit from branch to branch of the nearest tree, silently peeping into the cage with the utmost eagerness; all at once, he would dart off to a great distance as if afraid that he was about to be similarly imprisoned; or getting the better of his fears, he would perch on a conspicuous bough and snap his bill, calling check, check, seemingly in a great passion; again he would sing his loudest notes by way of challenge, or perhaps meaning to express his independence and superiority. Our cage-bird, meanwhile, was by no means a passive spectator of all this; and never failed, on the appearance of the other, to give voice to his best song and to endeavour to out-sing him, since he could not get at him to engage in personal conflict.

(Emberiza), and the pheasants, are familiar examples. A very remarkable illustration, however, of the remark of Aristotle, occurs in the summer-duck (Anas Sponsa, LINN.) of America, which, though not exactly a ground builder, does not seem out of place to be mentioned here, as one of the birds which line their nests with their own down. At variance with the habits of all other ducks, this one perches on trees, for which its strong sharp claws render it more adapted than its webbed feet. The elegant form and rich colouring of the male (though the female wears a uniform of dull brown) have excited the admiration of all who have seen it; and we think it not unlikely that the Indians took the hint of their plumed headdresses from its beautiful crest. With this crest and the skin of the neck, the calumet, or pipe of peace, is frequently ornamented. Linnæus, whose nomenclature exhibits some singular displays of fanciful allusion, imagined that this duck's crest so much resembled the bridal head-dress of his country-women, that he named it the bride (Sponsa), though the one is high, stiff, fantastic, and out of all reasonable proportion, while the other is free, elegant, and graceful.

The beautiful pendant crest of the summer-duck arises from a base of glossy golden green, shading off into a rich violet brown, dashed with interrupted streaks of snow white. The feathers covering the wings are of the same glossy brown, which melts into black, with rich purple reflections of burnished steel; while those on the flanks are delicately fringed and striped with black and white. But as words are not fitted to convey a correct notion of its varying and variegated colours, we shall pass on to our more immediate subject-the nest.

It is stated in the notes to Buffon, by the English translator, that the summer-duck nestles in the holes bored by the woodpeckers; but this, on considering