THE COURTSHIP OF INSECTS 259 



conspicuous — i.e. warning colours. That this distinction 

 actually obtains in nature is emphasized by Professor 

 Poulton. " If an artist " (he writes), " entirely ignorant of 

 natural history, were asked to arrange all the brightly 

 coloured butterflies and moths in England in two divi- 

 sions, the one containing all the beautiful patterns and 

 combinations of colour, the other including the staring, 

 strongly contrasted colours, and crude patterns, we should 

 find that the latter would contain, with hardly an excep- 

 tion, the species in which independent evidence has shown, 

 or is likely to show, the existence of some unpleasant 

 quality. The former division would contain the colours 

 displayed in courtship and when the insect is on the alert, 

 concealed at other times." 



Beetles often present very remarkable sex-differences, 

 notably the great horns which are carried by many of the 

 males. That these are frequently more ornamental than 

 useful seems likely ; but in some instances they are 

 employed in love-warfare between rival suitors. Several 

 males of the common stag-beetle (Lucanus cervus) at 

 times pay court to the same female, and engage in fierce 

 conflict for her possession. Another beetle, mentioned 

 by Darwin, dwells in pairs in the same burrow during 

 the breeding season, and when two insects have once 

 set up housekeeping, woe betide the rival who may 

 attempt to force an entrance. Not only does the male 

 attack him fiercely, but the female stands on guard at 

 the mouth of the burrow, and encourages her lord in his 

 defence by pushing him from behind. Wallace, again, 

 describes a conflict between two male beetles that were 

 paying court to the same female, " who stood close by 

 busy at her boring. They pushed each other with their 

 rostra, and clawed and thumped, apparently in the greatest 

 rage." Eventually the smaller beetle acknowledged his 



