. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings. "nnd obviously for the same ; In male dragon-flics, "the appendages at the tip of the tail are modified in an almost infinite variety of curious patterns to enable them to embrace the neck of the ; Lastly, in the males of many in- sects, the legs are furnished with peculiar spines, knobs, or spurs; or the whole leg is bowed or thickened, but this is by no means invariably a sexual character; or one p
. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings. "nnd obviously for the same ; In male dragon-flics, "the appendages at the tip of the tail are modified in an almost infinite variety of curious patterns to enable them to embrace the neck of the ; Lastly, in the males of many in- sects, the legs are furnished with peculiar spines, knobs, or spurs; or the whole leg is bowed or thickened, but this is by no means invariably a sexual character; or one pair, or all three pairs are elongated, sometimes to an extravagant ; In all the orders, the sexes of many species present difierences, of which the meaning is not understood. One curious case is that of a beetle (fig. 9), the male of which has the left mandible much enlarged; so that the mouth is greatly distorted. In another Carabidous beetle, the Eurygna- thus,' we have tlie unique case, 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 extraordinary is that cer- tain male butterflies have their fore-legs Fi 9 â Taphro- "^^rc or Icss atrophied, with the tibioD and deres (listortus tarsi reduced to mere rudimentary knobs. (much enlarged). â¢' Uppur ligiirc. ^hc wincTS, also, in the two sexes often differ male; lower flg- b â > i ure, female. jji ncuratiou,'" and sometimes considerably about Pcnthe, and others in inverted commas, are taken from Mr. Walsh, ' Practical Entomologist,' Philadelphia, vol. ii. p. 88. * Kirby and Spence, ' Introduct.' etc., vol. iii. pp. 332-336. ' 'Insecta Maderensia,' 1854, p. 20. " E. Doubleday, 'Annals and Mag. of Nat. Ilist.' vol. i. 1848, p. Please note that these images are extracted from scanned page images that may have been
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Keywords: ., bookcentury1800, bookdecade1870, booksubj, booksubjecthumanbeings
