52 BIRDS or NOEFOLK. 



of the stream, with its many shallows and rank growth 

 of weeds and grasses, has special attractions, and though 

 during severe frosts the shoally margins are covered 

 with ice and snow, it is rarely indeed that the current 

 ceases to flow in mid-channel. In like manner, they 

 are attracted by the shallow weed- choked waters of the 

 smaller broads,* both on the Bure and the Yare, as well 

 as by the presence of tame swans upon our inland pools 

 and lakes, some of which, never having been pinioned, 

 are not unfrequently shot during sharp winters in mis- 

 take for wild ones. Two whoopers were shot on the 

 small ponds at Hempstead, near Holt, on the 9th of 

 January, 1868. 



The distribution of colour on the bill in this species 

 forms the most marked external distinction between it ' 

 and the mute or tame swan (Cygnus olor), in the for- i 

 mer the base of the bill being yellow and the extremity ] 

 black ; in the latter, the base black and the extremity i 

 flesh-coloured, or reddish orange, according to age. The 

 internal differences exhibited by the whooper in the 

 convolutions of the trachea are also very marked, as 

 shown by Yarrell in his anatomical illustrations, but 

 that these had not escaped the observation of Sir 

 Thomas Browne is shown by his remark (when writing 

 of the " elks" or wild swans), that in them, " and not 

 in common swans, is remarkable that strange recurva- / 

 tion of the wind pipe through the sternum, and the ^ 

 same is also noticeable in the crane." The rufous ' 

 tinge on the head and cheeks, in the wild swan as 



* St. John, in tlie work before quoted, thus describes the habits 

 of wild swans in Scotland — " While they remain with us they fre- 

 quent and feed in shallow pieces of water like Lochlee, and Loch 

 Spynie, &c., where the water is of so small a depth that in many 

 places they can reach the bottom with their long necks, and pick 

 up the water grasses on which they feed." 



