Fig. 6. (A-C) Colour picture and the patterns of the degree and angle of polarization of Epipremnum aureum (Aracea) - illuminated by light from a full clear sky from above through the glass panes of a greenhouse - measured by video polarimetry at a wavelength of 450 nm (blue). In part C, the regions are represented in black where <10%. Number of pixels = 560x736=412160. (D) Colours (M_R, M_G and M_B) of E. aureum perceived by a polarization-blind retina, with P_B=P_G=P_R=1, and ß_R, ß_G, ß_B = arbitrary (a), and by a polarization-sensitive retina, with P_B=P_G=P_R=2, =0°, ß_B=0° as a function of the microvillar directions ß_G and ß_R of the green and red receptors (b-m). Every microvilli situation is designated by a letter ranging from a to m. The corresponding spectral loci (designated by letters a-m) of two details of the picture, one on a leaf blade (white) and one on the spathe (black) marked by rectangular windows in patterns A-C, are plotted within the equilateral R-G-B colour triangle, the colourless centre of which is represented by +.