Chap. XIII. 
YOCAL MUSIC, 
59 
The head-crest and neck-appendage are rudimentary 
in the female.^"* 
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 
Fig. 40. Tile Umbrella- Bird or Cephalopterus ornatus (male, from Brehm). 
‘I convoluted, like a Frencli horn, and is deeply embedded 
I in the sternum. In the wild swan {Cygnus ferus) it is 
'! 
I Bates, ‘ The Naturalist on the Amazons,’ 1863, vol. ii. p. 281 
! Wallace, in ‘Proc. Zool. Soc.’ 1850, p. 206. A new species, with a still 
larger neck-appendage (0. 'penduliger), has lately been discovered, see 
‘ Ibis,’ vol. i. p. 457. 
1 
