26 THE WAY OF A TROUT WITH A FLY 



as suggesting an opinion that trout are blind to any one or 

 two of the primary colours. That is not the suggestion at 

 all. Nature is not so simple as that. But it is quite 

 another matter to say that, because man has a highly- 

 developed sense of colour, therefore trout, if capable of 

 colour-sense at all, must see colour as man sees it. There 

 are degrees of colour-consciousness in man, and it would 

 surely not be a great stretch of imagination to conceive 

 that trout's sensitiveness to different colours may well be 

 different from that of man. He may be more or less 

 sensitive to some colours, and relatively less or more 

 sensitive to others — possibly extremely insensitive to some; 

 and he may be sensitive to some beyond man's colour 

 scale. 



If this be conceded, merely as a basis for argument, 

 it would certainly be found to result in trout seeing like- 

 nesses of colour where man sees differences, and perhaps 

 differences of colour where man sees likenesses. 



In a previous chapter I have, I think, made it fairly 

 clear that trout do see likenesses where man sees differences, 

 and differences where man sees likenesses. Is it too big 

 a jump in reasoning to infer that there may be some 

 variation in degree of sensitiveness to different colours 

 between the eye of the trout and the eye of man ? 



But can it be doubted that if the fly dresser knew 

 exactly the degree of the trout's sensitiveness and insensi- 

 tiveness to different colours, and also knew the combina- 

 tions of colour producing any particular shade for the 

 trout, he would have gone a very long way towards solving 

 the secrets of fatally successful trout-fly dressing ? 



It is, I think, beyond dispute that trout are extremely 

 sensitive to red and are greatly attracted by it. Witness 

 the value of a Red Tag to a fly. Living as so many do among 

 surroundings of green weed with a diet of insects in so 



