368 THE DESCENT OF MAN. 



proved that the sound was intimately connected with tliis appa- 

 ratus (which reminds us of the air-sacks on each side of the mouth 

 cf certain male frogs), for he found that the sound was miich 

 diminished when one of the sacks of a tame bird was prickeO., 

 and when both were, pricked it was altogether stopped. The 

 female has "a somewhat similar, though smaller naked space of 

 "■5kin on the neck; but this is not capable of inflation."" The 

 male of another kind of grouse (Tetrao urophasianus), whilst 

 courting the female, has his "bare yellow (Esophagus inflated to a 

 'prodigious size, fully half as large as the body;" and he then 

 uLters various grating, deep, hollow tones. "With his neck-feath- 

 ers erect, his wings lowered, and buzzing on the ground, and 

 his long pointed tail spread out like a fan, he displays a variety 

 of grotesque attitudes. The oesophagus of the female is not in 

 any way remarkable.'" 



It seems now well made out that the great throat pouch of 

 the European male bustard (Otis tarda), and of at least four 

 other species, does not, as was formerly supposed, serve to hold 

 water, but is connected with the utterance during the breeding- 

 season of a peculiar sound resembling "ock."'" A crow-like bird 

 inhabiting South America (Cephalopterus ornatus, fxg. 40) is 

 called the umbrella-bird, from its imniense top-knot, formed ot 

 bare white quills surmounted by dark blue plumes, which it can 

 elevate into a great dome no less than five inches in diameter, 

 covering the whole head. This bird has on its neck a long, thin, 

 cylindrical fleshy appendage, which is thickly clothed with scale- 

 like blue feathers. It probably serves in part as an ornament, 

 but likewise as a resounding apparatus; for Mr. Bates found 

 that ii is connected "with an unusual development of the trachea 

 "and vocal organs." It is dilated when the bird utters its singu- 

 larly deep, loud and long sustained fluty note. The head-crest 

 and neck-appendage are rudimentary in the female.'" 



" 'The Sportsman and Naturalist in Canada,' by Major W. Ross 

 King, 1866, pp. 144-146. Mr. T. W. ■^ATood g.ves in the 'Student' (April, 

 1870, p. 116) an excellent account of the attitude and habits of this 

 bird during its courtship. He states that the ear-tufts or neck-plumes 

 are erected, so that they meet over the crown of the head. See his 

 drawing, flg. 39. 



■'- Richardson, 'Fauna Bor. American: Birds,' 1S31, p. 359. Audubon 

 ibid. vol. iv. p. 507. " 



''= The following papers have been lately written on this subject: 

 Prof. A. Newton, in the 'Ibis,' 1S62, p. 107; Dr. CuUen, ibid. 1865, p. 145; 

 Mr. Flower, in 'Prcc. Zool. Soc' 1865, p. 747; and Dr. Murie, in 'Proc. 

 Zool. Soc' 1868, p. 471. In this latter paper an excellent figure is given 

 of the male Australian Bustard in full display with the sack distended. 

 It is a singular fact that the sack is not developed in all the males of 

 the same species. 



'" Bates, 'The Naturalist on the Amazons,' 1863, vol. ii. p. 284: Wal- 



