Identifier: descentofmansele02darw (find matches)
Title: The descent of man, and selection in relation to sex
Year: 1871 (1870s)
Authors: Darwin, Charles, 1809-1882
Subjects: Evolution Natural selection Heredity Human beings -- Origin Evolution
Publisher: London, J. Murray
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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like blue feathers. It pro-bably serves in part as an ornament, but likewise as aresounding apparatus, for Mr. Bates found that it isconnected with an unusual development of the trachea and vocal organs. It is dilated when the bird uttersits singularly deep, loud, and long-sustained fluty note. ^^ Eichardson, Faiina Bor. Americana: Birds, 1831, p. 359. Au-dubon, ibid. vol. iv. p. 507. 3 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 excellentfigure is given of the male Australian Bustard in full display with thesack distended. Chap. XIII. VOCAL MUSIC. 59 The lieacl-crest and neck-appendage are rudimentaryin tlie female.^ The vocal organs of various web-footed and wadingbirds are extraordinarily complex, and differ to a certainextent in the two sexes. In some cases the trachea is
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Fig. 40. The Umbrella-Bird or Cephalopterus ornatus (male, from Brebm). convoluted, like a French horn, and is deeply embeddedin the sternum. In the wild swan (Cygnus ferns) it is 4-* Bates, * The Naturalist on the Amazons, 1863, vol. ii. p. 284 ;Wallace, in Proc. Zool. Soc. 1850, p. 206. A new species, with a stilllarger neck-appendage (C penduliger), has lately been discovered, see Ibis, vol. i. p. 457. 60 SEXUAL SELECTION : BIRDS. Part IL more deej)ly embedded in the adult male than in thefemale or young male. In the male Merganser theenlarged portion of the trachea is furnished with anadditional pair of muscles^^ But the meaning of thesedifferences between the sexes of many Anatidae is notat all understood ; for the male is not always the morevociferous ; thus with the common duck, the male hisses,whilst the female utters a loud quack.^ In both sexes ofone of the cranes (Grus virgo) the trachea penetratesthe sternum, but presents certain sexual modifications.In the male of the bla

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