Heredity and sex . Fig. 13. — Great bird of Paradise, male and female.(After Elliot.) In birds ther€ are many cases in which the sexes differin color (Figs. 13 and 14). The male is often morebrilliantly colored than the female and in other casesthe nuptial plumage of the male is quite different fromthe plumage of the female. For example, the blackand yellow colors of the male bobolink are in strikingcontrast with the brown-streaked female (Fig. 15).The male scarlet tanager has a fiery red plumage withblack wings, while the female is olive green. The male 28 HEREDITY AND SEX of the mallard duck
Heredity and sex . Fig. 13. — Great bird of Paradise, male and female.(After Elliot.) In birds ther€ are many cases in which the sexes differin color (Figs. 13 and 14). The male is often morebrilliantly colored than the female and in other casesthe nuptial plumage of the male is quite different fromthe plumage of the female. For example, the blackand yellow colors of the male bobolink are in strikingcontrast with the brown-streaked female (Fig. 15).The male scarlet tanager has a fiery red plumage withblack wings, while the female is olive green. The male 28 HEREDITY AND SEX of the mallard duck has a green head and a reddishbreast (Fig. 16), while the female is streaked with insects the males of some species of beetles havehorns on the head that are lacking in the female (). The males of many species of butterflies are col-ored differently from the Fig. 14. — White-booted humming bird, two malesand one female. (After Gould.) The phosphorescent organ of our common firefly,Photinus pyralis, is a beautiful illustration of a second-ary sexual character. On the under surface of the malethere are two bands and of the female there is a singleband that can be illuminated (Fig. 18). At night themales leave their concealment and fly about. A littlelater the females ascend to the tops of blades of grass THE EVOLUTION OF SEX 29
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Keywords: ., boo, bookcentury1900, bookdecade1910, booksubjectsex, bookyear1913
