SUPERIOR LONGEVITY. 125 



them under. In 1796 the Marquis put two pair of 

 swans on the water. They completely cleared away 

 the weeds the first year, and none have since appeared, 

 as the swans eat them before they rise to the surface. 

 In the Low Countries, swans are kept for the same 

 purpose. 



The antiquity of this delicate and stately bird, the 

 silent swan, is conspicuous in the pages of history and 

 of poetry. The prototype of the domesticated breed 

 has been probably lost in the lapse of time, since the 

 wild swans of all countries differ essentially both in 

 plumage and organic structure, from the tame. The 

 longevity of the swan seems to equal, if not exceed, 

 that of any other animal, as it is said to live three 

 centuries, a fact, which it seems strange, and is to be 

 regretted, has not been correctly ascertained in some 

 of our great families of old, so extremely attached to 

 this noble bird. Hence I beg leave to recommend 

 to the keepers and amateurs of the swan, to open a 

 stud-book, wherein a sufficient number of individuals 

 may be named and marked ; and even that extracts 

 may be introduced into the wills of present and suc- 

 ceeding proprietors, that our posterity may be better 

 informed on this branch of natural history than our- 

 selves. They are chiefly to be found upon the 

 Thames, and probably also, as in former days, on the 

 inlet of the sea near Abbotsbury, Dorset, and in the 

 river Trent. Upon the Avon, in Warwickshire, how- 

 ever, as I am informed by a late sojourner in that 

 vicinity, wild swans are frequently seen ; they are in 

 colour white and grey, and in size smaller than the 



