Sends MS of his paper, "On the coloration of flowers and fruits", filling a gap in CD’s theory relating to these structures, and asks for CD’s comments.

Plans a book on colour sense.

Thanks for comments on paper and references to related works. Clarifies points on colour distinction between energy-absorbing (green) and energy-expending (bright-hued) portions of plants and on the influence of flower colour in modifying the insect organism.