Cole and Long, Visual Discrimination in Raccoons. 663 



Group 1^. 



{Decenibcr 26, 1901.) 



Ilering's Gray Paper No. 15 = 15 per cent white. 



Orange 1 



Red-orange shade 1 1 



Violet 1 



Green-bine shade 1 2 



Orange-red 2 



Group 20. 



{Deconhcr 27, 1007.) 



Ilering's Gray Paper No. 20 = 11.25 per cent white. 



Violet shade 1 



P>lue-violet shade 1 



Bine 



Violet-blue •. 1 



Red-orange shade 2 1 



Red-violet shade 1 2 



Group 25. 



(June 2S, 1907.) 



Hering's Gray Paper No. 25 = 9.S per cent white. 



Blue-violet shade 2 



Violet-blue shade 1 



Blue shade 1 



Red-orange shade 2 0'^ 



Violet shade 1 0^^ 



Group 30. 



(December 27, 1907.) 



Ilering's Gray Paper No. 30 = 7.75 per cent white. 



Violet-red shade 2 



Green-blue shade 2 1 



Orange-red shade 2 1 



Red-violet shade 2 2 



After we had secured a series of colors of equal brightness, as deter- 

 mined by the flicker method, we covered each of five ordinary drinking- 

 glasses, or tumblers, with one of the colored papers of the series, and 

 a sixth with the gray equal in brightness to the colors. These six 

 glasses, thus covered, with differently colored papers, were to be 



"Faded by December 2()th almost to match gray No. 20. 



