Read GA’s book [The colour-sense] with "great interest". Makes criticisms and suggestions.

Cannot believe in GA’s theory of the origin of pleasure and pain.

Is glad he defends sexual selection;

CD finds A. R. Wallace’s explanations "mere empty words" and for many years he has "quite doubted [ARW’s] scientific judgment".

Considers the possible effect of environmental colour on the colour tastes of animals.

Thanks for criticisms of Colour-sense.

Clarifies his views that actions desirable for species result in development of nervous organs capable of pleasurable stimulation.

Believes that all "tastes" occurring in nature are explicable with reference to ancestral habits and that none is purely arbitrary.