Archive image from page 357 of The descent of man . The descent of man : and selection in relation to sex descentofmanseledarw Year: 1874 344 THE DESCENT OF MAN. many insects and spiders, sound-producing instruments have, at least in some cases, been developed through sexual selection, as a means for bringing the sexes together. AMPHIBIANS. Urodela. —I will begin with the tailed amphibians. The sexes of salamanders or newts often differ much both in color and structure. In some species prehensile claws are developed on the fore-legs of the males during the breeding-season: and at this season
Archive image from page 357 of The descent of man . The descent of man : and selection in relation to sex descentofmanseledarw Year: 1874 344 THE DESCENT OF MAN. many insects and spiders, sound-producing instruments have, at least in some cases, been developed through sexual selection, as a means for bringing the sexes together. AMPHIBIANS. Urodela. —I will begin with the tailed amphibians. The sexes of salamanders or newts often differ much both in color and structure. In some species prehensile claws are developed on the fore-legs of the males during the breeding-season: and at this season in the male Triton palmipes the hind-feet are pro- vided with a swimming-web, which is almost completely absorbed during the winter; so that their feet then resemble those of the Fig. 32. Triton cristatus (half natural size, from Bell's 'British Rep- tiles'). Upper figure, male during tlie breeding-season; lower fig- ure, female. female. This structure no doubt aids the male in his eager search and pursuit of the female. Whilst courting her he rapidly vibrates the end of his tail. With our common newts (Triton punctatus and cristatus) a deep, much Indented crest is developed along the back and tail of the male during the breeding-season, which disappears during the winter. Mr. St. George Mivart in- forms me that it is not furnished with muscles, and thererore can- not be used for locomotion. As during the season of courtship it becomes edged with bright colors, there can hardly be a doubt that it is a masculine ornament. In many species the body presents strongly contrasted, though lurid tints, and these become more vivid during the breeding-season. The male, for instance, of our 3Bell, 'History of British Reptiles,' 2nd edit. 1849, pp. 156-159.
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