300 The Descent of Man. Pabt 11 



engage in fierce conflicts. When Mr. A. H. Davis*' enclosed 

 two males with one female in a box, the larger male severely 

 pinched the smaller eoe, until he resigned his pretensions. A 

 friend informs me 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 with the higher animals. 

 The males would seize hold of his finger, if held in front of 

 them, but not so the females, although they have stronger 

 jaws. The males of many of the Lucanidce, as well as of the 

 above-mentioned Leptorhynchus, are larger and more powerful 

 insects than the females. The two sexes of Lelhrus cepha'ofes 

 (one of the Lamellicorns) inhabit the same burrow; and the 

 male has largtsr 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 con- 

 tinually pushing him on from behind ; and the battle lasts until 

 the aggressor is killed or runs away.'" 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" believes, 

 would remain on the same spot until she died. 



The great mandibles of the male Lucanidse 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 StaphylinidsB. A perfect series can be formed from the 

 best-provided to the worst-provided or degenerate males. Al- 

 though the mandibles of the common stag-beetle, and probably 

 of many other species, are used as efllcient weapons for fighting, 

 it is doubtful whether their great size can thus be accounted 

 for. We have seen that they are used hy i\xo Lumnus elaphus 

 of N. America for seizing the female. As they are so con- 

 spicuous and so elegantly branched, and as owing to their great 

 length they are not well adapted for pinching, the suspicion 

 has crossed my mind that they may in addition serve as an 

 ornament, like the horns on the head and thorax of the various 

 species above described. The male Ohiamgnathus Grant ii of 

 S. Chile — a splendid beetle belonging to the same family — has 



'° 'Entomological Magazine,' vol. " Quoted from Fischer, in 'Diet. 



■. 1833, p. 82. See also on tht Class. d'Hist. Nat.' tom. x. p. 324. 



conflicts of this species, Kirby ano " 'Ann. Soc. Entomolog. France,' 



Spenoe, ibid. vol. iii. p. .Si4-; and 1866, as quoted in 'Journal of 



ft'estwoud, ibid. vo.. i. p. 187. Tri.?el,' by A. Murray, 1868, p. 135. 



