444 MR WILSON ON THE SUPPOSED IDE-^TITY Ot 
this circumstance of the non-occurrence of the Golden Eagle { 
upon Mr Se ley's theory. 
Reasoning from analogy, we should expect quite a dif- 
ferent succession of colours from that which is presumed ■ 
regularly to take place by those who coincide in Mr Selby's i 
opinion. For example, in the case of the Sea Eagle, and ^ 
the White-tailed Eagle, so long described as distinct spe- 
cies, but now ascertained and admitted to b6 the same, we ■ 
find that those with the brown tail are the young, and that 
the great proportion of white, which is afterwards assumed, ^ 
is the characteristic mark of the matured species. And in 
his description of the Falco imperialism still more nearly ' 
allied to the Golden Eagle, M. Temminck writes as fol- 
lows : " Les individus un -^qm plus avances en age, out des 
teintes plus foncees ; le blanc sur quelques-unes des plumes ■ 
scapulaires est plus marque, et quelques plumes noirdtres 
et d'un hrun Jvnce, paraissent sur toutes les parties d " 
corps."'' Indeed, I believe that although no general prin 
eiple has hitherto been formally established on the subject by . 
ornithologists, yet most of those who are conversant in the - 
general changes of plumage will admit, that a change from - 
The Royal Eagle draws his vigorous young, 
Strong pounc'd, and ardent with paternal fire. 
Now fit to raise a kingdom of their own, 
He drives them from his fo^rt, the towering seat 
For ages of his empire ; v/hich in peace 
Unstain'd he holds, while many a league at sea 
He wings his course, and preys in distant isles. 
The circumstance alluded to, of the old eagle driving its young to a dis- 
tance, whether it is as true as Thomson has rendered it poetical, is consist- 
ent with' early observation. It is related by Pliny : " Adultos persequitur , 
parens, et longe fugat, semulos scilicet rapince. Et alioqui unum par aqui- 
larum magno ad populandum tractu, ut satietur, indiget." Sec Dr Aikin's 
Essay on the Application of Poetrrf to Natural Hisiory, 
