Chap. X. COLEOPTERA. 375 



Professor Westwood states, " in which the central horn 

 '* of the thorax is very largp, but the horns of the head 

 " quite rudimental ; and others, in which the thoracic 

 " horn is much shorter, whilst the protuberances on 

 " the head are long." 62 Here, then, we apparently 

 have an instance of compensation of growth, which 

 throws light on the curious case just given of the loss of 

 the upper horns by the males of Onitis furcifer. 



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

 fitted for fighting, nevertheless engage in conflicts for 

 the possession of the females. Mr. Wallace 63 saw two 

 males of Leptorliynchus angustatus, a linear beetle with 

 a much elongated 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, acknowledging himself van- 

 " quished." In some few cases the males are well 

 adapted for fighting, by possessing great toothed man- 

 dibles, 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 period 

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

 Davis 64 enclosed 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 



02 ' Modern Classification of Insects,' vol. i. p. 172. On the same 

 page there is an account of Siagouium. In the British Museum I 

 noticed one male specimen of Siagonium in an intermediate condition, 

 so that the dimorphism is not strict. 



63 ' The Malay Archipelago,' vol. ii. 1869, p. 27G. 



64 ' Entomological Magazine,' vol. i. 1833, p. 82. See also on the 

 conflicts of tliis species, Kirby and Spence, ibid. vol. iii. p. 311; and 

 Westwood, ibid. vol. i. p. 187. 



