348 THE WOKLD OF LIFE 



render it more probable that the infinitely complex arrange- 

 ments by which such structures are produced and transmitted 

 unfailingly to offspring, should have been brought about for 

 this purpose alone, when thousands of other species arrive 

 at the same end by far simpler means. 



E"ow if there was a difficulty in the view that all the wealth 

 of colour and beauty in birds has been developed solely on 

 account of its utility to themselves, that difficulty becomes 

 greatly increased in the case of these insects. The described 

 butterflies alone are already far more numerous than birds, 

 and there are certainly more to be discovered of the former 

 than of the latter. Bates well observed that the expanded 

 wings of butterflies seemed to have been used by nature to 

 write thereon the story of the origin of species. To this we 

 may, I think, add that she has also used them, like the pages 

 of some old illuminated missal, to exhibit all her powers in 

 the production, on a miniature scale, of the utmost possibili- 

 ties of colour-decoration, of colour-variety, and of colour- 

 beauty ; and has done this by a method which appears to us 

 unnecessarily complex and supremely difficult, in order per- 

 haps to lead us to recognise some guiding power, some supreme 

 mind, directing and organising the blind forces of nature in 

 the production of this marvellous development of life and 

 loveliness. 



It must always be remembered that what is produced on 

 the flow^er, the insect, or the bird, is not colour, but a surface 

 so constituted in its chemical nature or mechanical texture 

 as to reflect light of certain w^ave-lengths while absorbing or 

 neutralising all others. Colour is the effect produced on our 

 consciousness by light of these special wave-lengths. To claim 

 that the lower animals, especially the mammals, perceive all 

 the shades and intensities, the contrasts and the harmonies of 

 colours as we perceive them, and that they are affected as we 

 are with their unequalled beauty is a wholly unjustified 

 hypothesis. The evidence that such sensations of colour exist 

 in their case is wholly wanting. All wc really know is, that 



