File:Heredity and sex (1913) (14578200138).jpg

Identifier: hereditysex00morg (find matches)
Title: Heredity and sex
Year: 1913 (1910s)
Authors: Morgan, Thomas Hunt, 1866-1945
Subjects: Heredity Sex
Publisher: New York, N.Y. : Columbia University Press
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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Text Appearing Before Image:
Fig. 57. — Six-shafted bird of paradise.(After Elliot.) ornaments that occur in no other birds. In the kingbird of paradise there are^ remarkable fans at thesides of the body of the male that can be expanded.The feathers of the fan are emerald-tipped. Thetwo middle feathers of the tail are drawn out intowires with a green web at one side of the tip. In mammals, secondary sexual differences are very no HEREDITY AND SEX common, although starthng differences in color arerather rare. In the male the coat of fur is often darkerthan that of the female. In many deer the antlers are present in the malealone. In Stellers sea-lion the male is much largerand stronger than the female. In a race of the Asiaticelephant the male has tusks much larger than thoseof the female. If we fix our attention exclusively on these remarkable
Text Appearing After Image:
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 ^brilhant 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.

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