that they meet over the crown of the head. See his drawing, Fig. 39.)
The male of another kind of grouse (Tetrao urophasianus), whilst
courting the female, has his bare yellow oesophagus inflated to a
prodigious size, fully half as large as the body ; and he then utters
various grating, deep, hollow tones. With his neck-feathers 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. (42.
Richardson, Fauna Bor. Americana: Birds, 1831, p. 359. Audubon, ibid.
vol. iv. p. 507.)
[Fig. 40. The Umbrella-bird or Cephalopterus ornatus, male (from
Brehm).]
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 oak. (43. The following papers have been lately written on
this subject: Prof. A. Newton, in the Ibis, 1862, p. 107; Dr. Cullen,
ibid. 1865, p. 145; Mr. Flower, in Proc. 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.) A crow-like bird
inhabiting South America (see Cephalopterus ornatus, Fig. 40) is called
the umbrella-bird, from its immense top knot, formed of 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 it is connected with an unusual
development of the trachea and vocal organs. It is dilated when the
bird utters its singularly deep, loud and long sustained fluty note.
The head-crest and neck-appendage are rudimentary in the female. (44.
Bates, The Naturalist on the Amazons, 1863, vol. ii. p. 284; Wallace,
in Proceedings, Zoological Society, 1850, p. 206. A new species, with
a still larger neck-appendage (C. penduliger), has lately been
discovered, see Ibis, vol. i. p. 457.)
399