Colour -Vision Corrv- e 



Froc Boy. Soc. Vol 51. PI 3. 



2 3 4 5 



I I 



Color Blindness. 



Ila. 



6 7 



II 



8 9 



II 



Red Blindness. Green Blindness. 



lib. 



10 11 



II 



12 13 



II 



Red Blindness. Green Blindness. 



W. GRIGGS, LITH 



