VOCAL, MUSIC. 



369 



The vocal organs of various web-footed and wading birds are 

 extraordinarily complex, and differ to a certain extent in the two 

 sexes. In some cases the trachea is convoluted, like a French 

 horn, and is deeply embedded in the sternum. In the wild swan 



Fig. 40. The Umbrella-bird or Cephalopterus ornatus (male, from 



Brehm). 



(Cygnus ferns) it is more deeply embedded in the adult male, 

 than in the adult female or young male. In the male Merganser 

 the enlarged portion of the trachea is furnished with an additional 

 pair of muscles.** In one of the ducks, however, namely Anas 

 punctata, the bony enlargement is only a little more developed 

 in the male than in the female.*" But the meaning of these dif- 

 ferences in the trachea of the two sexes of the Anatidse Is not 



lace, in 'Proc. Zool. Soc' 1850, p. 206. A new species, with a still larger 

 neck-appendage (C. penduliger), has lately been discovered, see 'Ibis,' 

 vol. i. p. 457. 



*^ Bishop, in Todd's Cyclop, of Anat. and Phys.' vol. iv. p. 1499. 



*> Prof. Newton, 'Proc. Zoolcg, Soc.' 1871, p. 651 



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