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.” The situations chosen by this bird for the purpose of nidification vary with the nature of the locality it inhabits; the eggs are usually deposited in the holes of trees, but they are also placed in fissures in the rocks wherever they may present a convenient site: the crevices of the white cliffs bordering the Murray, in South Australia, are annually resorted to for this purpose by thousands of this bird, and are said to be completely honeycombed by them. The eggs are two in number, of a pure white, rather pointed at the smaller end, one inch and seven lines long by one inch two and a half lines broad. All the plumage white, with the exception of the elongated occipital crest, which is deep sulphur-yellow, and the ear-coverts, centre of the under surface of the wing, and the basal portion of the inner webs of the tail-feathers, which are pale sulphur-yellow; irides and bill black; orbits white; feet greyish brown. The figures are somewhat smaller than the natural size. [Illustration: CACATUA LEADBEATERI: _Wagl._ _J. Gould and H.C. Richter del et lith._ _C. Hullmandel Imp._ ] CACATUA LEADBEATERI, _Wagl._ Leadbeater’s Cockatoo. _Plyctolophus Leadbeateri_, Vig. in Proc. of Comm, of Sci. and Corr. of Zool. Soc., Part I. p. 61; Lear’s Ill. Psitt. pl. 5; and in Phil. Mag. 1831, p. 55.—Gould in Syn. of Birds of Australia, Part IV.—Mitch. Australian Expeditions, vol. ii. p. 47. _Cacatua Leadbeateri_, Wagl. Mon. Psitt, in Abhand., p. 692. _Jak-k̏ul-yȁk-kul_, Aborigines of the mountain districts of Western Australia.