489 



THE MUTE SWAN. 



CYGNUS OLOR. 



Wliole plumage pure white ; bill red ; edges of the mandibles, nail, lore, orifice 

 of the nostrils, and large tubercle at the base of the beak, black ; irides brown ; 

 feet black. Young Urcls ash-bro^\Ti ; bill and legs dusky grey. Length five 

 feet. Eggs dull greenish white. 



This is the half- domesticated Swan of our rivers and 

 ornamental waters ; a native of many of the countries of 

 Europe and Asia, and, at one time, perhaps, found wild in 

 Britain. 



Popular works on natural history contain so many anec- 

 dotes of the Swan, and. the bird is so completely within 

 the reach of every one interested in the subject, that it is 

 thought unnecessary to give a detailed account of it in 

 this volume. I may observe only that in this species the 

 structure of the windpipe is far less complicated than in 

 the Hooper and Bewick's Swan, and that, though not 

 absolutely voiceless, its note, which is soft and low, is 

 not often uttered. 



THE POLISH SWAN. 



CYGNUS IMMUTABILIS. 



Resembling the last, except that the tubercle is smaller ; the elongated openings 

 of the nostrils do not reach the black at the base of the bill ; feet slate-grey 

 Young birds white. Length four feet eleven inches. 



This Swan, called " immutable " from the fact that there 

 is no difference between the colour of the plumage of the 

 cygnet and the adult, was constituted into a distinct species 

 by ]\Ir. YarreU. In structure it approaches the Mute 

 Swan, but is distinguished not only by the above characters, 

 but by anatomical features, for a full account of which the 

 reader is referred to "Yarrell's British Birds." Several 

 specimens have been obtained in this country, but nothing 

 peculiar has as yet been observed in its habits. 



