vi ORIGIN OF THE COLOUR-SENSE 415 



appearance ; and this seems quite in accordance with the vari- 

 ous facts set forth by Mr. Gladstone and the other writers 

 referred to. The fact that colour-blindness is so prevalent 

 even now is, however, an indication that the fully-developed 

 colour-sense is not of primary importance to man. If it had 

 been so, natural selection would long ago have eliminated the 

 disease itself, and its tendency to recur would hardly be so 

 strong as it appears to be. 



Concluding Remarks on the Colour-sense 

 The preceding considerations enable us to comprehend 

 both why a perception of difference of colour has become 

 developed in the higher animals, and also why colours require 

 to be presented or combined in varying proportions in order 

 to be agreeable to us. But they hardly seem to afford a 

 sufficient explanation either of the wonderful contrasts and 

 total unlikeness of the sensations produced in us by the chief 

 primary colours, or of the exquisite charm and pleasure we 

 derive from colour itself, as distinguished from variously- 

 coloured objects, in the case of which association of ideas 

 comes into play. It is hardly conceivable that the material 

 uses of colour to animals and to ourselves required such very 

 distinct and powerfully-contrasted sensations ; and it is still 

 less conceivable that a sense of delight in colour per se should 

 have been necessary for our utilisation of it. 



The emotions excited by colour and by music alike seem 

 to rise above the level of a world developed on purely utili- 

 tarian principles. 



