VOCAL ORGANS* 233 



thin membrane stretched over the opening, the whole 

 resembling in figure and texture the split reed of 

 those musical instruments, commonly called trom- 

 bones, so much esteemed in church service, and which 

 are widest at the lower end, with a similar fissure. 

 Eelow this the windpipe divaricates into two branches, 

 both of which enlarge towards the middle, or are 

 directly ramified through the lungs*. Dr. Latham's 

 description is, that " the windpipe in the wild swan 

 passes down the neck the whole of its length, after 

 which it enters the keel of the sternum [breast-bone], 

 passing backwards therein nearly the whole of its 

 length, when it bends upwards and forwards, and 

 then enters the cavity of the breast to communicate 

 with the lungs f." 



As this curious structure is not found in the tame 

 swan (Cygnus mansuetus, RAY), Willughby very 

 justly remarks, that " Aldrovand doth not rightly 

 infer that Aristotle never dissected this fowl, because 

 he makes no mention of this ingress, and of the 

 strange figure of the windpipe." He adds, " of 

 tame swans, we have anatomized many, and in all 

 have observed the windpipe to descend straight down 

 into the lungs, without any-such digression or de- 

 flection J." Ruffon, however, in conformity to the 

 theory which vitiates so many of his details, main- 

 tains that this difference of structure " is insufficient 

 to constitute two distinct species, for the variation 

 exceeds not the sum of the impressions, both internal 

 and external, which the domestic habits may in time 

 produce ." 



Recently, Mr. Wingate has discovered that there 

 are two species of wild swan, differing remarkably in 



* Aldrovandi OrrHhologia, iii. f> edit. Francf. 



f Linn. Trans, iv. 106. 



J Willughby, Ornith.by Ray, p. 356. 



Oiseaux, Art. Le Cygne. 



