If we regard the White Cockatoo of Van Diemen's Land, that of the continent of Australia, and that of New Guinea as mere varieties of each other, this species has a more extensive range than most other birds. It is an inhabitant of all the Australian colonies, both on the southern and northern coasts, but has not yet been observed on the western. On a close examination of specimens from the three countries above mentioned, a decided difference is observable in the structure of the bill, but of too trivial a character, in my opinion, to warrant their being considered as distinct; in fact, it would seem to be merely a modification of the organ for the peculiar kind of food afforded by the respective countries. The Van Diemen's Land bird is the largest in every respect, and has the bill, particularly the upper mandible, less abruptly curved, exhibiting a tendency to the form of that organ in the genus Licmetis: the bill of the New Guinea bird is much rounder, and is, in fact, fitted to perform a totally different office from that of the White Cockatoo of Van Diemen's Land, which I have ascertained, by dissection, subsists principally on the small bulbs of the terrestrial Orchidaceæ, for procuring which its lengthened upper mandible is admirably adapted; while it is more than probable that no food of this kind is to be obtained by the New Guinea bird, the structure of whose bill indicates that hard seeds, nuts, &c. constitute the principal part of its diet. The crops and stomachs of those killed in Van Diemen's Land were very muscular, and contained seeds, grain, native bread (a species of fungus), small tuberous and bulbous roots, and, in most instances, large stones. As may be readily imagined, this bird is not upon favourable terms with the agriculturist, upon whose fields of newly-sown grain and ripening maize it commits the greatest devastation; it is consequently hunted and shot down wherever it is found, a circumstance which tends much to lessen its numbers; it is still, however, very numerous, moving about in flocks varying from a hundred to a thousand in number, and evinces a decided preference to the open plains and cleared lands, rather than to the dense brushes near the coast. Except when feeding, or reposing on the trees after a repast, the presence of a flock, if not seen, is certain to be indicated by their horrid screaming notes, the discordance of which may be slightly conceived by those who have heard the peculiarly loud, piercing, grating scream of the bird in captivity, always remembering the immense increase of the din occasioned by the large number of birds emitting their disagreeable notes at the same moment; still I ever considered this annoyance amply compensated for by their sprightly actions and the life their snowy forms imparted to the dense and never-varying green of the Australian forest; a feeling participated in by Sir Thomas Mitchell, who says that "amidst the umbrageous foliage, forming dense masses of shade, the white Cockatoos sported like spirits of light."