Raises two points on CD’s view, in Descent [2: 229], on how aquatic birds acquire white plumage.

Also remarks on effect of will in certain human modifications,

on colour-blindness in his children,

and on ability to move his ears.

Thanks BvC for the present of his book, Sittlichkeit und Darwinismus.

Comments on Descent.

Reports a case of protective coloration of bugs on Tilia

and observations on frogs fighting [see Descent, 2d ed., pp. 281, 350].

Encloses drawings of chicken feet.

Has had Hinrich Nitsche’s pointed ear photographed. Nitsche also has photographed the ear of a foetal orang. [See Descent 1: 21–3.]

Gratified that CD approves his analysis of CD’s views of moral sense. Does not think there is a fundamental difference between J. S. Mill (Utilitarianism [1863], p. 45) and CD.

His view of those who object to CD’s "new doctrine of the moral sense".

On Hottentots’ blushing.

Gives case of a baboon’s revenge. [See Descent, 2d ed. (1874), p. 69.]

Man’s spiritual life separates him from other animals.

Why are moths attracted, often fatally, to lights?

Thanks for copy of Descent.