. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings. Chap. X. Insects. w. unique as far as known to Mr. Wollaston, of the head of the female being much broader and larger, though in a variable degree, than that of the male. Any number of such cases could be given. They abound in the Lepidoptera: one of the most extra- ordinary is that certain male butterflies have their fore-legs more or less atrophied, with the tibiae and tarsi reduced to mere ru- dimentary knobs. The wings, also, in the two sexes often differ in neuration,10 and some-


. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings. Chap. X. Insects. w. unique as far as known to Mr. Wollaston, of the head of the female being much broader and larger, though in a variable degree, than that of the male. Any number of such cases could be given. They abound in the Lepidoptera: one of the most extra- ordinary is that certain male butterflies have their fore-legs more or less atrophied, with the tibiae and tarsi reduced to mere ru- dimentary knobs. The wings, also, in the two sexes often differ in neuration,10 and some- times considerably in outline, as in the Ari- coris epitus, which was shewn to me in the British Museum by Mr. A. Butler. The males of certain South American butterflies have tufts of hair on the margins of the wings, and horny excrescences on the discs of the posterior In several British butter- flies, as shewn by Mr. Wonfor, the males alone are in parts clothed with peculiar scales. The use of the bright light of the female glow-worm has been subject to much discus- sion. The male is feebly luminous, as are the larvae and even the eggs. It has been sup- posed by some authors that the light serves to frighten away enemies, and by others to guide the male to the female. At last, Mr. Belt12 appears to have solved the difficulty: he finds that all the Lampyridse which he has tried are highly distasteful to insectivorous mammals and birds. Hence it is in accordance with Mr. Bates' view, hereafter to be explained, that many insects mimic the Lampyridse closely, in order to be mistaken for them, and thus to escape destruction. He further be- lieves that the luminous species profit by being at once recognised as unpalatable. It is probable that the same explanation may be extended to the 74. Mr. Wonfor's observations are quoted in * Popular Science Eeview,' 1868, p. 343. 12 ' The Naturalist in Nicaragua? 1874, pp. 316-320. On the phos- phorescence of the eggs, see * Annals an


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Keywords: ., bookcentury1800, bookdecade1890, booksubjecthumanbeings, bookyear