Color in the Visible and Invisible World 277 



there are correspondences of tone, color, and Prin- 

 ciple which, however they may vary individually, 

 are best comprehended by assuming a normal or- 

 der. 



If we hold in mind the fact that all evolu- 

 tion, all progression, is cyclic, or spiral, it will 

 help to a clearer comprehension of some puzzling 

 statements; for degree and number must depend 

 upon the grade the height on the spiral of 

 the color and key. 



