IN DEFENSIVE COLORATION 379 



IV. EPIGAMIC COLOURS. 



Epigamic Colours are the bright tints and patterns dis- 

 played during courtship. As in other classes of colours 

 the same effects may be produced by the use of foreign 

 objects {Allepigamic). Examples of this latter are found 

 in the various beautiful or curious objects collected by 

 bower-birds for the decoration of their bowers. Especially 

 interesting in this respect is \he. Amdlyoj^ms inornata'^ of 

 New Guinea. Although, strictly speaking, the subject 

 does not fall into the sphere defined by the title of this 

 Essay, the Epigamic is so closely related to the other 

 bionomic uses of animal colours that some brief account 

 appears to be necessary. 



The interpretation of these Secondary Sexual Characters 

 was first suggested by Darwin in the joint memoir con- 

 tributed by him and Wallace to the Linnean Society of 

 London, July i, 1858. It was further expounded in the 

 Origin of Species,^ and published in a complete form in 

 1871.^ The rivalry between males for the possession of 

 the female was, Darwin believed, decided by the prefer- 

 ence of the latter for those individuals with especially 

 bright colours, highly developed plumes, beautiful 

 song, &c. Wallace does not accept this theory, but 

 believes that the direct or indirect action of Natural 

 Selection accounts for all the facts. Probably the 

 majority of naturalists follow Darwin in this respect. 



The subject is most difficult, and the interpretation of 

 a great proportion of the examples in a high degree 

 uncertain, so that a very brief account is here expedient. 

 That selection of some kind has been operative is indi- 

 cated by the diversity of the elements into which the 

 effects can be analysed. 



The most complete set of observations on Epigamic 



excellent account of the flower-like Mantis, Hyvienopus, and an allied 

 species, in the living state. R. Shelford has shown that the newly- 

 hatched larvae of Hymenopus hicornis mimic a Reduviid bug ; see Proc, 

 Zool. Soc, Lond., 1902, vol. ii, pp. 231-2, pi. xix, figs. 16-19. 



^ London, 1859, pp. 87-90. 



^ Part II of The Descent of Man, and Selection in Relation to Sex. 



