282 NATATORES. CYGNUS. SWAN. 



(harsh as it may be individually), when heard at a distance, 

 has been compared to the enlivening cry of a pack of hounds. 

 To the known effect produced by the association of ideas 

 must doubtless be attributed the great pleasure which the 

 Icelanders display upon hearing the cries of the Swan, which 

 they compare to the notes of a violin ; but as a writer justly 

 observes, this is not to be wondered at, for they hear them 

 at the termination of a long and dreary winter, when the re- 

 turn of this bird to their shores is the earliest harbinger of 

 spring, foretelling a speedy thaw and release from a tedious 

 confinement. In dimensions and weight the present species 

 is commonly less than Cygnus Olor, in its tame or semi-do- 

 mesticated state, though adult males are sometimes met with 

 that equal the average size of the latter. It may, however, 

 always be distinguished from it externally by the different 

 form and colour of the bill, the position of the legs, differ- 

 ence of carriage, along with other peculiarities ; and inter- 

 nally, the conformation of the trachea exhibits a remarkable 

 difference. This part, instead of being a strait and simple 

 tube, as in Cyg. Olor, is prolonged, and enters a large cavity 

 hollowed out of the keel of the sternum, generally to the 

 depth of three and a-half or four inches, where it is doubled 

 back upon itself like a trumpet ; and which inflection is al- 

 ways vertical, never forming a loop or horizontal bend, as in 

 Cygnus Bewickii. After its egress from this cavity, the 

 tube is again turned upwards, and then, undergoing a con- 

 siderable diminution in diameter, terminates exactly upon 

 the ridge of the sternum in a compressed bony lower larynx, 

 or bone of divarication, shaped like the mouth-piece of a bas- 

 soon, and to which the bronchi, measuring upwards of three 

 inches in length, are attached. The flight of the Swan is 

 usually at a great elevation, and in a straight line ; and as 

 its wings are long and ample, its progress, with a favouring 

 breeze, is astonishingly rapid, and has been reckoned to ex- 

 ceed sometimes 100 miles in an hour. This velocity renders 

 it a difficult bird to shoot on wing, where so much allowance 



