LIGHT OF DIFFERENT WAVE-LENGTHS BY FISH 



39 



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Fig. 15 



The per-cent of correct choices of 20 successive trials for each of three sunfish 

 Dotted lines indicate rapid changes in width of slit. 

 Abscissae indicate successive slit widths in millimeters. 

 Ordinates percentages of correct choices at the given widths. 

 The numbers on the graphs indicate the successive groups of 20 trials from which 

 the percentages were calculated. 



