Fig. 3
From: Discrete or indiscrete? Redefining the colour polymorphism of the land snail Cepaea nemoralis
Interquartile ranges of the average normalised reflectance spectra for the principal component axes shown in Fig. 2. These plots confirm that variation on PC1 mainly represents differences in saturation between shells; PC2 represents relatively higher stimulation of L cones and lesser stimulation of M and S cones; PC3 represents relatively high stimulation of the M cones compared to lesser stimulation of the S and L cones
