File:The descent of man, and selection in relation to sex (1871) (14779944601).jpg

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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thus exposed the females soon begin their loud purring call, which can be heard a long way off, and any females within ear-shot run rapidly to the spot, and commence fighting with the caged bird.In this way from twelve to twenty birds, all breeding-females, may be caught in the course of a singleday. The natives assert that the females after layingtheir eixas associate in flocks, and leave the males tosit on them. There is no reason to doubt the truthof this assertion, which is supported by some observa- ^^ For the Australian tpecies, see Goulds Handbook, &c., vol. ii. p.178, 180, 18G. and 188. In the British IMuseum specimens of theAustralian Plain-wanderer (Pecliononnis torquatus) may be seen, show-ino- similar sexual diflerences. 202 SEXUAL selection: bikds. Part II. tions male in China by Mr. Swinhoe.^^ Mr. Blythbelieves, that the young of both sexes resemble theadult male. The females of the three species of Painted Snipes(Rhvnohoea) are not only larger, but much more richly
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Fig. GO, Ehynchaea capensis (from Biebni). coloured than the males. ^^ With all other birds, inwhich the trachea differs in structure in the t\Ao sexes 5 Jerdon, Birds of Indin, vol. iii. p. 506. Mr. Swiiihoe, in Ibis,1865, p. 542; 1866, p. 131, 405. ^^ Jerdon, Birds of India, vol. iii. p. 677. Chap. XVL THE YOUXG LIKE THE AUULT MALES. 203 it is more developed and complex in the male than inthe female; but in the Bhynehsea Australis it is simplein the male, whilst in the female it makes four distinctconyolntions before entering the lungs.^^ The femaletherefore of this species has acquired an eminentlymasculine character. Mr. Blyth ascertained, by exa-mining many specimens, that the trachea is not con-voluted in either sex of Fi. Beiigalensis, which speciesso closely resembles B,. Australis that it can hardly bedistiliguislied except by its shorter toes. This fact isanother striking instance of the law that secondarysexual characters are often widely different in closely-allied forms ;

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