Its principal food is a large kind of caterpillar, which it obtains from the wattle- and gum-trees, and in procuring which it displays the greatest activity and perseverance, scooping off the bark and cutting through the thickest branch until it arrives at the object of its search; it is in fact surprising to see what enormous excavations it makes in the larger branches, and how expertly it cuts across the smaller ones: besides these large caterpillars, it also feeds upon the larvæ of several kinds of coleopterous insects, and occasionally, but not generally, on the seeds of the Banksias and berries; chrysalides were also found in the stomachs of some that were dissected. I found it exceedingly difficult to obtain any particulars respecting the nidification of this bird, in consequence of its resorting for the performance of this duty to the most retired and inaccessible parts of the forests. Lieut. Breton, R.N., having informed me that a pair were breeding in a tree on the estate of Mr. Wettenhall, I requested him to use his influence with that gentleman to have their eggs procured for me, and on the 2nd of February 1839, I received a note from him in which he says:— “In compliance with your request, I wrote to Mr. Wettenhall upon the subject of the Black Cockatoo’s nest, and he forthwith directed his shepherd to fell the tree in which the bird had established itself. It was situated in a gulley or bottom, and was about four feet and a half in diameter. The hole was from ninety to one hundred feet from the ground, two feet in depth, and made quite smooth, the heart of the tree being decayed. There was no appearance whatever of a nest. The tree was broken in pieces by the fall, and the contents of the hole or nest destroyed; the fragments, however, were sought for with the greatest care, and all that could be found are sent you. It may perhaps be as well to state, that both while the tree was being felled and for a short time afterwards, a Hawk kept attacking the Cockatoo, which flew in circles round the tree before it fell, uttering its loudest and most mournful notes, and at times turning upon the Hawk, until at length it flew off.” The eggs are white, from two to four in number, and one inch and eight lines long by one inch and four lines broad. The bird varies considerably in size and weight, some specimens weighing as much as one pound and ten ounces, while others weighed no more than one pound and three ounces. The sexes, which differ but little from each other, may be thus described:—