. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings -- Origin. 366 SEXUAL SELECTION. [Part II. with any other family of the Coleoptera or beetles. With some species the males are provided with weapons for lighting; some live in pairs and show mutual affection; many have the power of stridulating when excited; many are furnished with the most extraordinary horns, apparently for the sake of ornament; some which are diurnal in their hab- its are gorgeously colored; and, last- ly, sever
. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings -- Origin. 366 SEXUAL SELECTION. [Part II. with any other family of the Coleoptera or beetles. With some species the males are provided with weapons for lighting; some live in pairs and show mutual affection; many have the power of stridulating when excited; many are furnished with the most extraordinary horns, apparently for the sake of ornament; some which are diurnal in their hab- its are gorgeously colored; and, last- ly, several of the largest beetles in the world belong to this family, which was placed by Linnaeus and Fabri- cius at the head of the Order of the Coleoptera.'. 67 Stridulating organs. — Beetles belonging to many and widely-dis- tinct families possess these organs. The sound can sometimes be heard at the distance of several feet or even yards,68 but is not comparable with that produced by the Orthoptera. The part which may be called the rasp generally consists of a narrow slightly-raised surface, crossed by very fine, parallel ribs, sometimes so fine as to cause iridescent colors, and having a very elegant appearance under the microscope. In some cases, SantS" for instance, with Typhceus, it could female male;1°werfigure' be plainly seen that extremely mi- 67 Westwood, 'Modern Class.' vol. i. p. 184. 68 Wollaston, On certain musical Curculionidae, ' Annals and Mag. of Nat. Hist.' vol. vi. 18G0, p. 14. Fig. 23. — Chiasocrnathus. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Darwin, Charles, 1809-1882. New York, D. Appleton and company
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectevoluti, bookyear1872
