438 Mil WILSON ON THE SUPPOSED IDENTITY OF 
and yet not the result of a difference in age^ may be re- 
garded as of very considerable value in the discrimination 
of the species, and adduced as a fair argument in proof of 
their distinction. 
I shall now refer to some more general considerations, 
which I should deem of themselves sufficient to prove that 
the Golden Eagle cannot be regarded as the young of the 
Ring-tail. 
In the British dominions, the Golden Eagle is, perhaps, 
the rarest of the feathered tribe. The Ring- tail, on the 
contrary, though no where abundant, is yet sufficiently well 
known, and is called the Black Eagle in the Scottish High, 
lands, to distinguish it from the Great Erne, or Sea-Eagle, 
the most numerous of the British aquiline birds. In Swit- 
zerland, and among the Alps of Savoy, Northern Italy, 
^nd the Tyrol, the Ring-tail is the most common species 
of any ; whereas the Crolden Eagle continues to be there, 
as it is with ourselves, a bird of comparatively rare occur* 
rence. Now, it appears, I think, reasonable to conclude, 
that if the Golden Eagle were merely the young of the 
Ring-tailed Eagle, it would not only be as common as that 
species, but much more so ; because, if every pair of adult 
Ring-tailed Eagles breed once in each season, and produce 
two young at a brood, and if these young take three years 
to attain their perfect plumage, it follows, that at the lapse 
of every period of three years, there would be three pair of 
young Golden Eagles for every single pair of adult Ring, 
tailed Eagles which existed at the commencement of that 
period, — ^in other words, that the Golden Eagle would be 
at least three times more common than the Ring-tailed one. 
The reverse of this is, however, the case ; the Ring-tailed 
Eagle being not only three times, but probably six, or 
eight, or even ten times more common than the Golden one. 
How, then, can it be the pavent of that species ? 
