Swan. NATATORES. CYGNUS. 283 
is necessary to be made, according to the supposed distance 
of the object. When caught alive, it soon becomes very 
tame, as seen in the instance mentioned by Monracu ; and 
I have also, in several cases, known it survive for a long 
time, and thrive well, when provided with plenty of water ; 
it refuses, however, to associate with the common or mute 
species.—The food of the Swan consists of the roots, leaves, 
and stems of aquatic plants, in obtaining the former of which 
its length of neck is of essential service, which it has also the 
power of keeping submerged for a long time ; but as this is 
done by the mute species perhaps in an equal degree, it can- 
not be attributed to the peculiar form of the trachea, an idea 
that has been suggested by different ornithologists. In the 
present species, the elastic process or joint, in the upper man- 
dible, which enables it to be opened to a considerable extent, 
is very prominent, and more easily distinguished than in 
many others of the Anatide, in whom it is hidden by the 
knob, or by the feathers of the brow. When swimming, the 
neck is borne erect, at a right angle with the body, and. sel- 
dom arched, as is the custom of the Common Swan; but in 
walking (which is performed in a heavy and awkward man- 
ner), the head is lowered, and the neck reclines over the 
back, in order to preserve the equipoise of the body. 
Prats 47. Represents this bird in scarcely one-third of the 
natural size. 
Average length five feet; breadth from seven to eight. 
Bill four inches long from the tip to the brow, black, 
and having the basal part covered with a lemon-yellow- 
coloured cere, that, extending backwards, encircles the 
eyes. Head and nape of the neck generally speckled 
with pale orange-yellow ; the rest of the plumage in 
adults being pure white. Legs black. 
The young birds are of an uniform pale grey, with the 
cere and naked skin around the eyes pale flesh-red. 
Legs reddish-grey. 
Food. 
General 
descrip- 
tion. 
Adult. 
Young. 
