44 ORNAMENTAL WATERFOWL. 
but have not since continued to do so regularly. Respecting 
Cygnus nigricollis 1 have a note to the following effect from 
the pen of Mr. Edwin H. Banks, of Wigton, in Cumberland. 
He states that his Black-necked Swans went blind during the 
winter, which apparently was too severe for these tropical 
birds, while the Black Swan bred freely, nesting both in the 
spring and autumn. It would probably be found necessary 
to keep the Black-necked Swan in a sheltered enclosure, with 
a warmed sleeping house, on its first arrival in this country, 
and to pay special attention during the first moult, which often 
proves fatal to newly-imported birds. The species is, however, 
now so firmly established in Europe, that it would be easier 
to procure hardy home-bred specimens than recent importa- 
tions; the value of this Swan being generally about £20 to 
425 the pair. 
Male.—Body pure white; head and neck glossy black, 
with a white line round the eye; bill gray, with a patch of red 
on the upper side; feet dark pink. 
Female.—Similar. 
Young.—White when hatched, acquiring the black neck 
at the first feathering. 
Egg.—Greenish-grey ; six to seven in number. May— 
June. Incubation, thirty-four to thirty-six days. 
COMMON OR MUTE SWAN. 
(Cygnus olor). 
This variety is the best known of all the Swans, a pair being 
found upon almost every piece of ornamental water of sufficient 
size ; they may be said to exist in a state of semi-domestication, 
being undoubtedly the descendants of the Wild Swan, which 
