of New Holland and Tasmania . 
395 
equally fine female, in the possession of the Hon. Henry Elliott, 
at Government House, had the irides bright yellow. 
“ In the size and admeasurement of the various parts of either 
sex of the white and grey birds, no difference whatever can be 
detected ; another reason for believing them to be the same: for 
wherever a specific difference is found to exist, it is always accom¬ 
panied by a difference in the dimensions of the whole or parts of 
the structure. 
u A knowledge of the nidification of this and the preceding 
bird, and of the state of their plumage, from youth to maturity, 
would greatly tend to settle the question of their identity. 
* * # * * 
“ The sexes differ very considerably in size, the male being 
scarcely more than half the size of the female. 
“ The whole of the plumage pure white; cere and legs, yellow ; 
bill and claws, black.” 
In the masterly “ Description of the Australian Birds,” pub¬ 
lished in the Linnean Transactions, about twenty years ago, 
Messrs. Vigors and Horsfield state—“ There are two specimens of 
this bird (the White Hawk) in the British Museum, and we have 
seen two other specimens, exactly according with ours, which 
were lately brought to this country from New Holland; we have 
also heard of some other specimens. We have therefore little 
doubt of its being a distinct species; and not the Albino variety 
of another, as suggested by M. Cuvier, in his < Regne Animal/” 
Now, if Mr. Gould had never visited Australia, his opinion, like 
that of M. Cuvier, might have been accounted for; and it would 
not have carried with it much weight. He acknowledges that the 
Astur Raii is confined to New South Wales, and yet he is convinced 
that it is the parent of a species, which, notwithstanding the war 
of extermination carried on against it for the last forty years, is 
still common, and not sparingly (as he asserts), but pretty nume¬ 
rously distributed over Tasmania. 
If an Albino, it is surely more than probable that the parent 
bird, from which it was derived, would sometimes at least be 
found in Tasmania; but not one specimen of Astur Raii has 
ever been seen by me in all my wanderings, during a residence of 
2 f 2 
