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SEXUAL SELECTION. 
Part II> 
that when a boy he often put the males together to see 
them fight, and lie 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. 
With many of the Lucanidae, as well as with the above- 
mentioned Leptorhynchns, the males are larger and 
more powerful insects than the females. The two sexes 
of Lethrus cephalotes (one of the Lamellicoms) inhabit the 
same burrow ; and the male has larger mandibles than 
the female. If, during the breeding-season, a strung® 
male attempts to enter the burrow, he is attacked; the 
female does not remain passive, but closes the mouth ot 
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 awav . 65 The 
two sexes of another lamellicorn beetle, the Ateuch ** 
cicatrieosus 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 d 
she is removed, he becomes much agitated. If the 
male is removed, the female ceases all work, and a® 
M. Brulerie 06 believes, would remain on the spot until 
she died. 
The great mandibles of the male Lucanidae are ex- 
tremely variable both in size and structure, and in tlii g 
respect resemble the horns or the head and thorax 
of many male Lamellicorns and Stapliylinidre. A per- 
fect series can be formed from the best-provided to the 
worst-provided or degenerate males. Although the 
mandibles of the common stag-beetle, and probably of 
03 Quoted from Fiselier, in ‘ Diet. Class. d’Hist. Nat.’ tom. x. p. 324- 
60 ‘Ann. Soc. Eutomolog. France,’ 1866, as quoted in ‘Journal 
Travel,’ by A. Murray, 1868, p. 135. 
