Survey of tlie Colour Vision of 1000 Students. 197 

 " Fig-. 8. 



40 



ZO 



BLACK TEST 

 WOMEN 

 P = -40 



n 



r^^' 



/ 



7 



\ 



10 



20 



Fiff. 9. 



20 



RED-GREEN TEST 

 WOMEN 

 P=-75 



£ZL 



J=M^ 



_L_ 



l\ 



\ 



10 



20 



Fiar. 10. 



20 



10 



BLUE-GREEN TEST _ 

 WOMEN 

 P-74 



Abscissae represent distance from focus in millimetres, 

 ordinates number of observers. 



