CHAPTER II 

 COLOUR PERCEPTION IN FISH 



(Re-written from "Land and Water," November 6, 1897) 



MANY interesting problems constantly 

 come before the fisherman, but certainly 

 one of the most interesting which has 

 recently attracted his attention is Sir 

 Herbert Maxwell's theory on the power 

 of fish to discriminate between various 

 colours. 



His theory is, that though fish can un- 

 doubtedly discriminate between different 

 shades of light and dark, they cannot dis- 

 tinguish one colour from another. The 

 only conclusion that can be drawn from 

 this theory is the conclusion at which Sir 

 Herbert Maxwell has apparently arrived. 

 This is, that if the same relations of light 

 and shade be maintained in the artificial 



