416 
RARE BIRDS KILLED IN THE WINTER OF 1837-8. 
also sometimes observable in old specimens. A Hooper on the lake in the 
Regent’s Park, where it has lived for at least six years, has the crown more 
deeply rust-coloured than in any other that I have yet seen ; and a friend informs 
me that one of the common domestic species, in his possession, which also is, 
at the least, six years old, is very deeply tinged with rust-colour all over. A 
male Polish Swan, also, in St. James’s Park (which was purchased as the parent 
of the female, with which it appears likely to breed this season, and therefore 
cannot be much under that age, as Srvans do not reproduce before they are two 
years old), is tinged on the head and neck with rust-colour. I could cite addi¬ 
tional instances if necessary. 
The Polish Swan ( Cy.gn.us immutabilis ) is an accession made this winter to 
the British fauna; and considering the numbers which have been killed along 
the range of the eastern counties, from Aberdeenshire to Kent, I have been 
surprised that none have been sent to the London market. Mr. Leadreater 
had several sent to him for stuffing, and one, out of four that had been shot from 
a flock near Maidstone, was lent by him to Mr. Yarrell, for the purpose of 
exhibition before the Zoological Society, when the species was characterized. 
This bird scarcely differs from the ordinary Mute species, all the characters of 
which it presents in an inferior degree of development; but it is smaller, and 
pure white at all ages, even in its first downy covering. As a distinct race, it 
has long been recognized by several of the dealers, who have designated it—I 
know not for what reason—the Polish Swan. The Ornithological Society pur¬ 
chased an adult pair, with a young one, of which the old female soon died, early in 
last year. At first, I am told, all three were equally remarkable for the very pale 
colour, almost whiteness, of the legs and feet, by which only they were obviously 
distinguishable from the common tame Swan; but at present, although this 
pallid hue still continues to distinguish conspicuously the young female, the male 
has the feet as dark as any specimen of C. olor. Assuredly, however, the com¬ 
mon tame Swan has dark-coloured feet at every age and season. 
It is probable that the opinions of naturalists will continue to be divided 
respecting the validity of C. immutabilis to be considered a species. In its 
anatomy it does not differ from C. olor; but I should not on this account infer 
their specifical identity—that is, their descent from the same aboriginal parentage 
—as many obviously distinct species, wherever the arbitrary line of demarcation 
may be drawn, resemble each other so closely that it becomes impossible to 
assign the limits of approximation; and we do not know why there should, of 
necessity, be any difference whatever between the most nearly-allied of all. 
though aboriginally separate, races. At any rate, the occurrence of C. immuta¬ 
bilis in large flocks, in a true state of Mature, would seem to point it out as a 
genuine species; and let it be remembered, that so close a similitude exists in 
