258 
II. 
OH THE POLISH SWAN, Cygnus immuiabiliz, (Yarrell.) 
By T. Southwell, Hon. Secretary. 
Read 26 th Sept., 1876. 
Since Mr. Stevenson’s excellent monograph which I have just 
read (“ The Polish Swan,” printed for private circulation), was 
written, I have had several additional opportunities of examining 
Norfolk killed specimens of the Polish Swan ; and other important 
evidence has been accumulated, which tends greatly to strengthen 
my previous opinion, that the so-called Cygnus immutabilis is 
really a true species. The Polish Swan has actually been bred in 
confinement by Lord Lilfoid, producing white cygnets ; and from 
these white cygnets his lordship has again bred another generation 
of white cygnets. Lord Lilford does not appear to have recorded 
this, and it was only in the course of conversation that it came to 
light. Upon being applied to by Mr. Stevenson, however, his 
lordship kindly wrote him full particulars of the occurrence, and 
at the same time expressed his decided opinion, that the species is 
a good one. Before, however, this was known, the Council of the 
Zoological Society, finding that the pair in their possession men- 
tioned by Mr. Stevenson did not breed in their confined home in 
the gardens, determined to intrust them to Mr. J. H. Gurney, 
hoping that more liberty and a change of quarters might induce 
them to breed. In the spring of the present year they were, 
accordingly, sent to Northrepps, where they at once settled, and 
in due time made a nest, and out of six eggs, produced five 
young ones, three on the 21st, and two on the 22nd of May; 
these were a delicate buff colour Avhen hatched, which gradually 
faded to pure white. When I first saw them on June 2nd, the buff 
tinge was hardly perceptible except on the back, which appeared 
of a rich creamy buff, with the under parts nearly pure white. O11 
the 16th of June the largest cygnet was killed by a rat and nearly 
destroyed; and on the 27th July, Mr. Gurney wrote me, that the 
cygnets were beginning to show some feathers, which were “ dull 
cinnamon brown, much like the first down.” About the 10th of 
