Birds. 1177 



swan has a soft and rather plaintive note ; in fact, from the re- 

 markable formation of their windpipes, Nature seems to have rendered 

 that most improbable. The hooper's voice is perhaps the most melo- 

 dious, although that is only hoarse, and fully answers to Virgil's de- 

 scription : — 



" Dant sonitum rauci per stagna loquacia cygni.'' 



Hence, singing swans, kokvci aoidoi, must still be accounted as fabulous. 



Bewick's Swan, Cygnus Beivickii. The eye in this swan is pla- 

 ced higher in the head and nearer to the crown than in the hooper ; 

 its bill also differs in being somewhat thicker at the base, and a little 

 less flat about the middle. It is smaller and rarer than the preceding. 

 An individual was shot in the winter of 1836-7, near Seaton : it was 

 opened and its trachea well examined. For the distinctions present- 

 ed by the windpipes, or tracheae, of the different swans, see the figures 

 in Yarrell's 'Brit. Birds,' vol. iii. at pp. 103, 111 and 12 i ; and the 

 * Linnean Transactions,' vol. iv. tab. 1*2, and vol. xvi. tab. 24 and 25. 

 In physical conformation the swan is one of the most highly organiz- 

 ed of birds, for it possesses the greatest number of cervical vertebrae 

 as well as of ribs ; namely, 23 of the former and 10 pairs of the latter : 

 also the muscles attached to the breast-bone are immensely strong ; 

 the sternum itself is deep and much lengthened, and so well protects 

 the intestines ; and the coracoid and furcula bones are large and pow- 

 erful. Hence, we find the effect of such an organization to be, that 

 the bird is able to sustain a long and steady flight, to swim admirably, 

 and to walk with considerable firmness and ease. The great number 

 of the vertebrae in the neck, which are so articulated as to permit its 

 being turned and curved in all directions, gives it a snake-like shape, 

 and renders it quite serpentine in its movements. But the neck of 

 the Plotus appears still more like a snake, and is longer in proportion 

 to the body than that of the swan ; although I do not know whether it 

 contains more than twenty-three vertebrae or not. 



Canada Swan, Cravat Swan, Anser Canadensis. I would place 

 this bird, which, from its long neck, most resembles a swan, in the 

 genus Cygnus. Mr. Jenyns has done the same, see ' Brit. Vertebrate 

 Animals,' p. 227. And the Baron Cuvier (Regne Animal, torn. i. p. 

 529. edit. 1817) adds in a note, — "me parait aussi uu vrai cygne." 

 Mr. Yarrell relates (Brit. Birds, vol. iii. p. 93) that Bewick says, 

 " great numbers of these Canadian geese were driven from their haunts 

 during the severe snow-storms of January and February, 1814; they 

 iii 4 (r 



