418 MUTE SWAN. 
in considerable numbers in Central and Southern Russia, and on 
the Lower Danube; sparingly on some of the lakes in Greece ; 
more abundantly in the vicinity of the Black and Caspian Seas, and 
in Turkestan. In winter the Mute Swan occurs on the waters of the 
greater part of Europe, and is a regular visitor to the lakes of Algeria 
and Egypt; it can also be traced through Asia to Mongolia, and to 
North-west India. 
According to the late Mr. H. Stevenson, Swans pair for life, and 
build a fresh nest each season ; this is generally on a small island or 
peninsula, and is a large struicture of reeds or coarse herbage. The 
females do not lay until their second year—some not till the third 
or fourth—and commence with 3-5 eggs, but later the clutch some- 
times consists of 10-12, which are dull greenish-white, averaging 
4 in. by 2°9 in. With wild birds incubation begins in May, but it is 
earlier in a state of semi-domestication. The young are hatched in 
about 36 days and are carefully tended by their mother, who 
frequently carries them on her back, to which she sometimes raises 
them with her foot, at the same time sinking her body low in the 
water. The food consists of water-plants (such as Chara), aquatic 
insects &c., also of grain, and bread. The note of the wild bird in 
pairing-time is loud and trumpet-like, but it is fainter in tame 
individuals. 
The adult male has the greater part of the bill reddish-orange, 
nail, nostrils, lores and the basal tubercle or “ berry” black ; plumage 
white ; legs and feet black. Length 56-60 in.; wing 27 in. The 
female is smaller and has far less tubercle. The cygnet is sooty- 
grey above, and paler below, with lead-coloured bill and legs. 
In the so-called “ Polish” Swan, C. zmmutadbilis of Yarrell, the 
cygnets are white, while the adult is said to have a less developed 
tubercle and ash-grey legs and feet; but neither the late Mr. A. D. 
Bartlett nor I could find these distinctions in old birds in the 
Zoological Gardens which had been white as cygnets. With the 
exception of a bird obtained in Holland in December 1840, few—if 
any—specimens of the “ Polish” Swan are known to have occurred 
outside the British Islands; and it is now generally considered by 
ornithologists to be a mere variety as regards the colour of the young. 
As pointed out by Prof. Newton, white cygnets were noticed on the 
Trent 200 years ago, while in 1885, 1886, and 1887 a pair of Swans 
at Cambridge produced broods in which some of the young were 
abnormally white (Zool. 1887, p. 463 ; 1888, p. 470); and Count 
Salvadori states that ‘“‘none of the characters attributed to 
C. immutabilis are constant” (Cat. B. Brit. Mus. xxvii. p. 38). 
