456 
ON THE MEALY LINNET. 
scarcely, if at all, distinguishable from some that might be picked out from a" 
number of examples of the race immediately superior. Still, I cannot help 
thinking that he is premature in thus uniting the three, as the great mass of 
individuals are readily distinguishable, and as we have yet to learn whether their 
song-notes are precisely similar, and indeed all that relates to the largest of them— 
the Parrot Crossbill—in its living state; besides which, of many American speci¬ 
mens which I have examined, I have never seen one that equalled the average 
size of the smaller European race, nor, of a considerable number of examples killed 
on this side the Atlantic, have I hitherto observed any so small as in the average 
size of the race inhabiting North America; neither, among heaps of the ordinary 
European Crossbill, has a single specimen occurred which had attained the normal 
contour of A. pgtiopsittacm: again, the existence of the dosely-allied L. leucoptera^ 
which fails to exhibit corresponding variation to that implied by the union of the 
other three as a single species, while it varies to the extent of either considered 
separately, affords analogical evidence of the others being truly distinct; and the 
near resemblance of its plumage, also, excepting merely the white upon the wings, 
may suffice to remove our marvel, nay tend even to create an anticipation that 
any other species still more allied to the common one, and wanting the peculiar 
white markings of L. leucoptera^ would be scarcely, even if at all, distinguishable 
from it. 
The two British species of Budytes correspond precisely in size and structure, 
also in their nidification, eggs, and even notes; and their only difference in colour 
—there being none in markings—is confined to the head: yet their haunts are 
somewhat different, and they have now been generally recognised as distinct species. 
Between the Colymbus halticus and C. arcticus a few shades of difference in the 
colour of the head, superadded to a considerable superiority of size on the part of 
the former, constitute the sole distinctions; and both inhabit the very same 
localities. The common Teals of Europe and America differ less in size, but more 
in the development of particular markings in the former, which are wanting or 
rudimental in the latter. There are three Jays (including the European), each pos¬ 
sessing a distinct geographical range, which can only be distinguished by slight 
diversities of colouring on the head; yet which there is no reason whatever to 
regard as not having been pristine. 
It would be easy to fill several pages with similar examples; and while, on the 
one hand, every gradation might be traced to the utmost dissimilarity; on the 
other, the very next step would be absolute resemblance, wherein the light of 
analogy only could lead to the suspicion of non-identity. In some few cases, 
indeed, a slight difference might obtain in the secondary or adjunctive characters ; 
as in the instance of the American Creeper, as opposed to the European ; for the 
eggs of the former (as described by Wilson and others) decidedly differ from 
