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Show 376 SEXUAL SELECTION. PART II. that when a boy he often put the males together to see them fight, and he noticed that they were much bolder and fiercer than the females, as is well known to be the case with the higher animals. The males would seize hold of his finger, if held in front, but not so the females. vVith many of the Lucanidrn, as ,,ell as with the abovementioned Leptorhynchus, the males are larger and more po·werful insects than the females. The two sexes of Leth?'US cephalotes (one of the Lamellicorns) inhabit the same burrow ; and the male has larger mandibles than the female. If~ during the breeding-season, a strange male attempts to enter the burrow, he is attacked; the female does not remain passive, but closes the mouth of the burrow, and encourages her mate by continually pushing him on from behind. The action does not cease until the aggressor is killed or runs away.m; The two sexes of another lamellicorn beetle, the Ateuchus cicatricosus live in pairs, and seem much attached to each other; the male excites the female to roll the balls of dung in which the ova are deposited; and if she is removed, he becomes much agitated. If the male is removed, the female ceases all work, and as M. Brulerie 66 believes, would remain on the spot until she died. The great mandibles of the male Lucanidrn are extremely variable both in size and structure, and in this respect resemble the horns on the head and thorax of many male Lamellicorns and Staphylinidrn. A perfect series can be foi·mecl from the best-provided to the worst-provided or degenerate males. Although the mandibles of the common stag-beetle, and probaLly of 65 Quoted from Fischer, in' Diet. Clnss. d'Hist. Nat.' tom. x. p. 324. 66 • Ann. Soc. Entomolog. France,' 18G6, as quoted in 'Journal of Tmvel,' by A. Mmray, 1868, p. 135. C JIAP. X. COLEOPTERA. 377 many other species, are used as efficient weapons for fighting, it is doubtful whether their great size can thus be accounted for. vVe have seen that with the L~tcanus ela; phus of N. America they are used ior seizing the female. As they are so conspicuous and so elegantly branched, the suspicion has sometimes crossed my mind that they may be serviceable to the males as an ornament, in the .same manner as the horns on the head and thorax of the various .above described species. The male Chiasognathus grantii of S . .Chile-a splendid beetle belonging to the same family-bas enormously- developed mandibles (fig. 23) ; he is bold and pugnacious ; when threatened on any side be faces round, opening his great jaws, and at the same time stridulating loudly ; but the mandibles were not strong enough to pineh my finger so as to cause actual pain. Sexual selection, which implies the possession of considerable per ·Ceptive powers and of strong passions, seems to have been more -effective with the Lamellicorns Fig. 23. Cbiasognathus grantii, than with any other family of the reduced. Upper figure, male; Coleoptera or beetles. With some lower fignn·, female. -species the males are provided with weapons for fiahting; some live in pairs and show mutual affection |