414 WHOOPER SWAN. 
sionally wanders to South Greenland, where it used to nest up to 
Godthaab, 64° N., until exterminated by the natives. In Norway it 
js seldom known to breed below the Arctic circle, but in Sweden, 
Finland, and Northern Russia it is found in summer down to 
lat. 62° N., while, up to 67°, at which Dr. Theel found it on the 
Yenesei, it can be traced across Siberia to Kamchatka and the 
Commander Islands. On migration it visits the estuaries and 
inland waters of Europe, as far south as the Mediterranean, Black 
and Caspian Seas, while in severe winters it reaches the lakes of 
Algeria, Lower Egypt, and Palestine ; it has once been obtained in 
Nepal, and occurs in Japan, Corea and China during the cold 
season. 
The nest is a large structure of coarse herbage, and is generally 
placed on an island in a lake, concealed in willow- or other scrub 
where such covert is available. The eggs, up to 7 in number, are 
pale yellowish-white: measurements 4°5 by 2°9 in. Incubation 
often begins in the latter part of May; and Dr. Palmén states that 
the young grow so slowly as to be unable to fly until the end of 
August, or even later. The food consists of the roots and stems 
of aquatic weeds, and of grass. The note is a loud and trumpet- 
like whoop, whoop-whoop, whoop, and, when uttered during flight, 
often forms a rhythmical accompaniment to the strokes of the pinions. 
The adult has the entire plumage white, with occasionally an 
adventitious ochreous tint on the feathers of the head; legs, toes 
and their webs black. The anterior part of the beak is depressed 
and black, while the basal portion is quadrangular and yellow; this 
latter colour extending forward beyond the openings of the black 
nostrils. Whole length of a male 60 in. (bill 4:2); wing 25°5 in. ; 
weight 22lbs. The female is smaller. The young bird has the 
beak of a dull flesh-colour, tipped and margined with black; the 
upper plumage ash-brown ; and the under parts paler as far as the 
flesh-coloured legs, the vent being white. Fairly adult plumage is 
attained by the second winter, but the shafts of the feathers on the 
back are dusky until the next moult. 
The Whooper (like all the other species of the genus found in the 
northern hemisphere—except the Mute or Tame Swan), has a 
remarkable cavity in the keel of the sternum into which the tube 
of the trachea passes and forms a parallel loop. In the Mute Swan 
the keel is single and unprovided with a cavity. Some further 
remarks will be found at the end of the next article. 
