892 TEE DESCENT OF MAN 



large, but the horns of the head quite rudimental; and 

 others, in which the thoracic horn is much shorter, while 

 the protuberances on the head are long. ' ' " Here we ap- 

 parently have a case of compensation, which throws light 

 on that just given of the supposed loss of the upper horns 

 by the males of OniUs. 



Law of Battle. — Some male beetles, which seem ill-fitted 

 for fighting, nevertheless engage in conflicts for the pos- 

 session of the females. Mr. Wallace" saw two males of 

 Leptorhynchus angustatus, a linear beetle with a much elon- 

 gated rostrum, "fighting for a female, who stood close by 

 busy at her boring. They pushed at each other with their 

 rostra, and clawed and thumped, apparently in the greatest 

 rage." The smaller male, however, "soon ran away, ac- 

 knowledging himself vanquished." In some few cases male 

 beetles are well adapted for fighting, by possessing great 

 toothed mandibles, much larger than those of the females. 

 This is the case with the common stag-beetle {Lucanus 

 cervus), the males of which emerge from the pupal state 

 about a week before the other sex, so that several may 

 often be seen pursuing the same female. At this season 

 they engage in fierce conflicts. When Mr. A. H. Davis" 

 inclosed two males with one female in a box, the larger 

 male severely pinched the smaller one, 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 Lucanidse, as well as of the above- 



" "Modern Classification of Insects," vol. i. p. 172: Siagonium, p. 172. 

 In the British Museum I noticed one male specimen of Siagonium in an inter- 

 mediate condition, so that the dimorphism is not st 'ict. 



«8 "The Malay Archipelago," vol. ii., 1869, p. 276. Riley, Sixth "Report 

 on Insects of Missouri," 1874, p. 115. 



'* "Entomological Magazine," vol. i., 1833, p. 82. See also, on the conflicts 

 of this species, Kirby and Spence, ibid., vol. iii. p. 814; and Westwood, ibid., 

 vol. i. p. 187. 



