File:Heredity and sex (1913) (14757695666).jpg

Identifier: hereditysex1913morg (find matches)
Title: Heredity and sex
Year: 1913 (1910s)
Authors: Morgan, Thomas Hunt, 1866-1945
Subjects: Heredity Sex Heredity
Publisher: New York, Columbia University Press
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

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Fig. 58. — Wilsons phalarope, female (in center), male (to right andbehind). A bird in winter plumage is at the left. (From Eaton, Birds ofNew York.) cases where differences between the sexes exist, weget a one-sided impression of the development ofornamentation and color differences in animals. Wemust not forget that in many cases males and femalesare both highly colored and exactly alike. We forgetthe parrots, the cockatoos, the kingfishers, the crownedpigeons, toucans, lories, and some of the starlings;the ^brilliant todies and the ^^sluggish jacamarswhose brilliant metallic golden-green breasts rival SECONDARY SEXUAL CHARACTERS 111 those of the humming-birds; we forget the zebras,the leopards; the iridescent interiors of the shells ofmany mollusks; the bright reds and purples of starfish,worms, corals, sea anemones, the red, yellow, and greensponges, and the kaleidoscopic effect of the microscopicradiolarians ; — a brilliant array of color.
Text Appearing After Image:
Fig. 59. — (A), female of a copepod, Calocalanus plumosus.of Calocalanus parvus. (C) male of last. (B), a female In the egret both males and females have remark-able nuptial plumes, which, had they been present inone sex alone, would have been classified as secondarysexual characters. It does not appear that selectionhad anything to do with their creation. Our common screech owl exists in two colored typessharply separated. No one is likely to ascribe thesedifferences to sexual selection, yet if one sex had been 112 HEREDITY AND SEX red and the other gray, the difference would have beenput down to such selection. There are also cases likethe phalarope, shown in Fig. 58, where the female ismore highly ornamented than the male. In fact, forthese cases, Darwin supposed that the males selectthe females; and in support of this view he points outthat the females are more active, while the male con-cerns himself with the brooding of the eggs. In someof the marine copepods female ornamentat

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