NATURAL HISTORY SOCIETY OF GLASGOW. 109 



Mr. John M. Campbell exhibited a specimen of a Swan, on 

 which he remarked as follows: — 



On the 8th February last I purchased, at a poultry shop in 

 Glasgow, a Swan which had been killed about 10 miles from 

 Bamelton, County Donegal, Ireland. At first sight 1 thought the 

 bird was a large specimen of Bewick's Swan, Oygntis beitrickii, but 

 subsequent examination led me to doubt whether it was really the 

 bird described under that name by Yarrell. The chief point of 

 difference from the bird described by him is that the loop-like form 

 of the trachea, which lies in the cavity of the sternum, is, in this 

 specimen, absent. As the bird, although slightly larger than the 

 dimensions given by Yarrell, agrees in other respects with his C. 

 bewickii, this alteration in the character of the trachea might have 

 been an individual divergence from the normal type. But similar 

 sterna of reputed C. bewiefdi, examined by me, all exhibit the same 

 abnormal form, and on communicating with Prof. A. Newton on 

 the subject, he gave his opinion that the loop-like form -of the 

 trachea is not constant. What, then, is the true specific distinction 

 of Yarrell's C. bewickii? That distinguished ornithologist states 

 that "the principal and most obvious difference is in the trachea," 

 and he very fully explains its structure* as a point of great specific 

 value. If, then, in the specimens of C. bewickii, whose sterna L 

 have examined, and in the specimen now under consideration, 

 which Prof. Newton states is the largest he has ever seen or heard 

 of, we find the characters, on which Yarrell founded his species, 

 absent, may we not be led to suppose that it is much more rare 

 than is generally believed, and that a closely allied form is con- 

 founded with it 1 The doubt, if any, can only be thoroughly cleared 

 up by an examination of a good series of British species in the flesh, 

 and of different ages. 1 therefore wish to draw the attention of 

 the members of the Society to the question with that end in view. 



The specimen under notice, which is now in the Kelvingrove 

 Museum, was a male in rather poor condition, the stomach being 

 entirely empty. It weighed 12|- lbs., and measured as follows: — 

 Length, 52"; girth, 30^"; stretch of wing, 79"; length of wing, 38 J"; 

 length of wing from carpal joint, 22"; length of leg (tarso metatarsus), 

 4\"; foot, 6V; beak, measured along eulmen, -t"; greatest width of 

 beak, 1J"; length of tail from vent, SV ; length of sternum from 

 keel to apex, 7§". 

 * " History of British Birds by W. Yarrell," 3rd ed., 1856, vol. hi., p. 205. 



