Invites CD to join the Association of Liberal Thinkers and encloses information on its constitution. Huxley and Tyndall are co-operating.

Discusses colour variations in the geometer moth, Gnophos obscurata. Concludes that the increasing proportion of the darker form is related to the effect of smoke that is blackening the chalk slopes on which they live.

Invites RM to luncheon.

Glad to join Association of Liberal Thinkers and to pay usual subscription. Refuses any office and does not allow his name to be used to promote the association because neither his health nor his mental habits will allow him to take an active part.

THN, a medium with a gift to cure occult diseases, outlines a course of treatment to remedy CD’s ailments.

CD will visit tomorrow.

Invites [WKP] to lunch.

Thanks CD for his encouraging letter. Replies to CD’s points. Thinks more attention should be given to the origin and growth of sexual shame.

CD hopes his book [Movement in plants] will be worth the effort WTT-D has put into getting plants for him; fears he has achieved little.

Instructs FD to make some observations on movement in Trifolium and Impatiens. Sends some seeds to be sown.

Horse chestnut roots have not acted at all well.

Suggests experiment to detect salts deposited on surface of leaves.

Wants FD to have another go at horse-chestnut radicles.

Asks whether he may call to discuss a chemico-physiological point.

Many thnks for the pelargonium letter.

CD sends his preface [to RM’s translation of August Weismann, Studies in the theory of descent (1882); Collected papers 2: 280–1].

Thanks for preface. When RM’s translation is complete, would like CD to expand it slightly to refer to overlap between Weismann’s observations and CD’s theories.

Regrets he cannot compare his work with Weismann’s in his preface as he feels “an author is never a fit judge of his own work”. [Appended note explains that RM wished CD’s work to be fully acknowledged, which was frequently not the case in continental writings.]

Discusses views of Moritz Wagner on modification of species. Two different cases: one in which a species is modified in the same country and cases in which a species splits. Glad CGS is taking up subject.

Sends revises [of his Notes by a naturalist on the "Challenger", 1872–6 (1879)] and asks permission to dedicate it to CD.

Thanks for HNM’s offer to dedicate book [Notes by a naturalist on the "Challenger" (1879)].