POLISH SWAN. 
Cygnus immutabilis, YARRELL. 
Cygnus—A Swan. Immutabilis—Unchangeable. 
SEvERAL flocks of these birds were observed in this country 
in the beginning of the year 1838, during the severe weather 
of that period. Of a flight of thirty, seen near Snodland, 
on the Medway, in Kent, four were shot. One was procured 
in Cambridgeshire, in the winter of 1840-41. In the summer 
of the year 1844, Arthur Strickland, Esq. saw a flock off 
Burlington Harbour. They were all white, and one of them 
being obtained, and proving to be a young bird, its identity 
with the changeless Swan is at once apparent. 
One was shot in the marshes near Horning, Norfolk, Mr. 
M. C. Cooke informs me, on the 29th. of January, 1854. 
Thirteen were seen a Ingoldisthorpe, near Lynn, and one of 
them was shot, in December, 1851. Three are recorded in 
the ‘Naturalist,’ vol. ii, page 132, as having been killed out 
of a flock of nine, at the same place about the same time. 
I conclude that they formed part of the same flock—All 
‘Polish Refugees,’ and probably from Russia, the severity of 
whose climate has been only in keeping with her customs 
heretofore. 
This species is also tameable, and in confinement has bee 
known to pair with the Mute Swan. 
Male; length, four feet nine inches. The knob at the base 
of the bill is small; the beak itself is reddish orange, except 
the base and the edges, which are black; the tooth also 
is black; iris, brown. Head, crown, neck, nape, chin, throat, 
breast, and back, pure white. 
The wings have the second quill feather the longest. Greater 
and lesser wing coverts, primaries, secondaries, tertiaries, greater 
