POLISH SWAN. 133 



it had been preserved by Mr. Leadbeater. It was one of 

 four, shot on the Medway, near Snodland Church, Avhere a 

 flock of thirty, and several smaller flocks were seen. 



The circumstance of these flocks being seen, without any 

 observable difl^erence in the specimens obtained, all of which 

 were distinct from our Mute Swan ; the fact, also, that the 

 cygnets, as far as observed, were of a pure white colour, like 

 the parent birds, and did not assume, at any age, the grey 

 colour borne for the greater part of the first two years by the 

 young of the other species of Swans ; and an anatomical dis- 

 tinction in the form of the cranium, to be hereafter noticed, 

 which was described by Mr. Pelerin, in the Magazine of 

 Natural History, induced me to consider this Swan entitled 

 to rank as a distinct species, and, in reference to the un- 

 changeable colour of the plumage, I proposed for it the name 

 of Oygyius immutahilis. 



I have very recently been favoured with a letter from the 

 Earl of Derby, who some years since purchased a pair of 

 Polish Swans in London, and sent them to Knowsley. The 

 female in this instance also, unfortunately, died. The male 

 paired with a Mute Swan, and a brood was produced ; but the 

 hybrids, though now old enough, have neither paired among 

 themselves nor with any of the Mute Swans on the same 

 water. 



I have heard of one Polish Swan shot in Cambridgeshire, 

 and now preserved in the Wisbeach Museum ; and another 

 was shot in the winter of 1840-41. This species, however, 

 does not appear to have been distinguished elsewhere from 

 the Mute Swan, and I am therefore unable to name any 

 foreign geographical localities as producing it, beyond the 

 probability of its inhabiting those countries in the vicinity 

 of the Baltic. 



In the adult bird the beak is reddish-orange ; the nail, 

 lateral margins, nostrils, and base of the upper mandible 



