XI THE SPECIAL COLOURS OF PLANTS 335 



colour sense on the animal integuments.^ He argues that the 

 colours of insects and birds reproduce generally the colours of 

 the flowers they frequent or the fruits they eat, and he 

 adduces numerous cases in which flower-haunting insects and 

 fruit-eating birds are gaily coloured. This he supposes to be 

 due to the colour -taste, developed by the constant presence 

 of bright flowers and fruits, being applied to the selection of 

 each variation towards brilliancy in their mates ; thus in time 

 producing the gorgeous and varied hues they now possess. 

 Mr. Allen maintains that "insects are bright Avhere bright 

 flowers exist in numbers, and dull where flowers are rare or 

 inconspicuous ; " and he urges that " we can hardly explain this 

 ■wide coincidence otherwise than by supposing that a taste 

 for colour is produced through the constant search for food 

 among entomophilous blossoms, and that this taste has reacted 

 upon its possessors through the action of unconscious sexual 

 selection." 



The examples Mr. Allen quotes of bright insects being 

 associated with bright flowers seem very forcible, but are 

 really deceptive or erroneous ; and quite as many cases could 

 be quoted which prove the very opposite. For example, in 

 the dense equatorial forests flowers are exceedingly scarce, 

 and there is no comparison with the amount of floral colour 

 to be met with in our temperate meadows, woods, and hill- 

 sides. The forests about Para in the lower Amazon are 

 typical in this respect, yet they abound with the most 

 gorgeously coloured butterflies, almost all of which frequent 

 the forest depths, keeping near the ground, where there is the 

 greatest deficiency of brilliant flowers. In contrast with this 

 let us take the Cape of Good Hope — the most flowery region 

 probably that exists upon the globe, — where the country 

 is a complete flower-garden of heaths, pelargoniums, mesembry- 

 anthemus, exquisite iridaceous and other bulbs, and numerous 

 flowering shrubs and trees ; yet the Cape butterflies are hardly 

 equal, either in number or variety, to those of any country 

 in South Europe, and are utterly insignificant when compared 

 with those of the comparatively flowerless forest-depths of 

 the Amazon or of New Guinea. Neither is there any relation 

 between the colours of other insects and their haunts. Few 



^ The Colour Sense, chap. ix. 



