diameter, and as much in depth. A very complete one is now lying before me, and the materials of which it is composed are as follows: The outward coat is formed of small pieces of a species of bluish-grey lichen that vegetates on old trees and fences, thickly glued on with the saliva of the bird, giving firmness and consistency to the whole, as well as keeping out moisture. Within this are thick matted layers of the fine wings of certain flying seeds closely laid together: and, lastly, the downy substance from the great mullein, and from the stalks of the common fern, lines the whole. The base of the nest is continued round the stem of the branch to which it closely adheres, and, when viewed from below,

appears a mere mossy knot or accidental protuberance. The eggs are two, pure white, and of equal thickness at both ends. On a person's approaching their nest the

the greatest pleasure in minutely examining the figured patterns of the chair-covers, perhaps expecting to find something eatable among the leaves of the pattern. I reared a black-cap and some whitethroats, taken when a fortnight old, under a singing nightingale, and removed all other singing birds, but they sung their wild notes pretty truly; on the other hand, a black-cap, two years old, from hearing a nightingale sing a great deal, acquired two passages from its song, and executed them correctly, though not very powerfully. I understand that the robin, reared in a cage, is not observed to learn from other birds, but sings the wild note pretty accurately. I can at present suggest no key to these diversities; nor do I understand why the young nightingale, taken when the old birds cease to sing, will, in confinement, learn the note of other birds, and retain them, although it may hear its own species sing again as soon as they recommence in the autumn; and yet, at liberty, with the same cessation of the parental song, it would have learned nothing else; unless it be that from want of other amusement, it listens more when it is confined *"

But though we were to grant all the facts stated by these authors to be rigidly correct, we should not be disposed to adopt their conclusion, which is plainly opposed by other facts within the power of every observer to verify. We do not, however, believe Kircher's story of nestling birds hatched under other birds never attempting to sing, any more than we should believe that a human infant in like manner deprived of the care of its own species would speak Hebrew or high Dutch. "A skylark," it has been stated, "was taken from the nest before it was fledged and reared by the hand in town,

*Notes to White's Selborne, edit. 8vo. 1832.

take possession of them after they are abandoned by the owners*."

The yellow-bird (Carduelis tristis) just mentioned, itself sometimes called the American goldfinch, likewise makes a felt nest, prettily formed, like that of our chaffinch, of pieces of tree lichens on the outside, partly glued on with saliva, the inside being lined with whatever soft downy substance can be procured, and the whole fastened to the twigs of an apple-tree, or to the strong branching stems of hemp. The American redstart (Setophaga ruticilla, SWAINS.), again, fixes its nest still more accurately in the fork of a small sapling, or the drooping branches of the elm, by flax well wound together, into which are felted and glued with saliva, pieces of lichen, with a very soft lining of down. But as there would be no end to our enumeration of every individual finch or humming-bird which exhibit skill in felting together the materials of their nests, we think it will be more interesting to our readers to conclude this chapter with the lively narrative which Vaillant has given of the proceedings of a pair of small African birds.

This romantic though accurate naturalist had contrived by tempting tit-bits to render the species alluded to, which he calls the Capocier (Sylvia macroura, LATHAM), so familiar, that a pair of these birds regularly entered his tent several times a day, and even seemed to recognise him in the adjacent thickets as he passed along. "The breeding season," he goes on, "had no sooner arrived, than I perceived the visits of my two little guests to become less frequent, though, whether they sought solitude the better to mature their plans, or whether, as the rains had ceased and insects became so abundant that my tit-bits were less relished, I cannot tell, but they seldom made their appearance for four or five successive * Wilson, Amer. Ornith., ii, 56.

with them before they can provide for themselves, and that afterwards they frequent the same places as the rest of their kind; but, unfortunately for this explanation, the fact is that song-birds for the most part become silent after their young are hatched. Neither is it true, that song-birds associate exclusively with their own species, and, although they did, it would not follow that they never hear other birds. How then

does it happen, since they are, by the theory, so prone to imitation, that they never in a wild state intermingle the notes of others with those peculiar to their own species? Upon the principles of the theory every bird ought to be a polyglot.

We have in many instances verified the experiments of Barrington on caged birds, most of which when young will readily learn the notes of the birds in the same room. We have, for example, at present, a young cock green-bird (Fringilla chloris, TEMMINCK), which from hearing the call of the sparrows out of doors has acquired it perfectly, and from hanging near a black-cap, he has also learned many of its notes, though he executes them indifferently, perhaps from deficiency of voice. He has more recently attempted some of the notes of a robin whose cage hangs under his. Yet notwithstanding that he has thus learned part of the notes of three or four different birds, he can also utter the peculiar call-note of his own species, though we are pretty certain he has not heard it uttered since he left his parents' nest when only a few days old. But no wild green-bird ever learns in this manner the notes of various species, nor would our bird, we are well convinced, had he not been kept stationary in the cage, and consequently had the notes he has learned daily sounding in his ears, till he could not forget them. In a wild state, he would either have kept at a distance from other species, or would not have attended to them;

whereas, in the cage, he could not avoid hearing the sparrows, the black-cap, and the red-breast *.

Mr. Sweet is an advocate for the theory we are considering, from having observed similar facts without having adverted to the different circumstances in which wild and caged birds are placed. Of the red-start (Sylvia Phoenicurus), he says, "it may be taught to sing any tune that is whistled or sung to it: one that I was in possession of for some years back, learnt the Copenhagen waltz, that it had frequently heard sung, only it would sometimes stop in the middle and say chipput, a name by which it was generally called, and which it would repeat every time I entered the room where it was, either by night or by day t." M. Bechstein asserts, that the red-start "knows how to embellish its natural song (composed of several rather pretty strophes), by adding the notes of other birds with which it associates. One which had built under the eaves of my house imitated pretty closely a caged chaffinch in the window underneath; and my neighbour had another in his garden, which repeated some of the notes of a black-cap that had a nest hard by. This facility of appropriating the song of other birds, is rare in a wild state, and appears to be almost confined to this species." Even this anomalous instance may be easily explained on the principle we have stated, for the red-start having its nest near where the caged chaffinch was stationed was forced to hear its notes till they were impressed on its memory.

The researches of comparative anatomy have thrown much light upon the peculiar structure of song-birds, though there remain still many points of interest for future investigation. This indeed, as British Warblers, in loco. Taschenbuch, Art. Rothschwanzchen,

* J. R.