on warning colours and mimicry



CHAPTER X

COLOURS AND ORNAMENTS CHARACTERISTIC OF SEX


Sex colours in the mollusca and crustacea--In insects--In
butterflies and moths--Probable causes of these colours--Sexual
selection as a supposed cause--Sexual coloration of birds--Cause
of dull colours of female birds--Relation of sex colour to
nesting habits--Sexual colours of other vertebrates--Sexual
selection by the struggles of males--Sexual characters due to
natural selection--Decorative plumage of males and its effect on
the females--Display of decorative plumage by the males--A
theory of animal coloration--The origin of accessory
plumes--Development of accessory plumes and their display--The
effect of female preference will be neutralised by natural
selection--General laws of animal coloration--Concluding remarks



CHAPTER XI

THE SPECIAL COLOURS OF PLANTS: THEIR ORIGIN AND PURPOSE


The general colour relations of plants--Colours of fruits--The