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

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.]

Is glad book progresses; answers translation query.

Francis Darwin does not have time to lecture.

Sends the Fritz Müller article from Kosmos.

Wishes to subscribe to RM’s translation of Weismann.

Has seen Scudder’s article.

A. R. Wallace’s article ["Animals and their native countries", Nineteenth Century 5 (1879): 247–59] is excellent.

Suggests he write to Ernst Krause about publication of translation of Fritz Müller’s paper. FM’s view of mutual protection is quite new to CD.

Shares RM’s misgivings about Fritz Müller’s mutually protecting mimics. Would expect bird’s response to distasteful caterpillars to be instinctive. Believes J. J. Weir or Thomas Belt may have investigated the point.

Would like to subscribe to English edition of Weismann.

Thanks RM for information on case of hexadactyly [see RM’s paper, "Hexadactylism", Land and Water, 11 March 1871, p. 179.

Mentions the difficulties in explaining the separation of sexes and Carl Nägeli’s view that the sexes of plants were primordially distinct.

Has been experimenting for five or six years to demonstrate that the benefits of crossing are the same as those derived from a slight change of conditions.

Discusses the problems of mimicry as related to natural selection; the general variability of colour as a character; and the conditions necessary for natural selection to fix firmly a character.

Encloses a Fritz Müller letter speculating that organisms respond to certain colours because of the prevalence of those colours in their environment.

Invites RM to keep some specimens as long as he wishes.

Recalls vaguely the mention of a butterfly species in which the male alone is mimetic.

Feels it would be worth while but difficult to investigate mimicked and mimicking forms for structural similarities that would indicate a closer alliance in the past.

Thanks RM for note on ocelli.

Thanks RM for his paper on mimicry.

Cannot answer RM’s query because he believes it impossible to define large variations.

Believes monstrosities are generally injurious and are not often, if ever, taken advantage of in nature.

Has reread copy of Fritz Müller’s letter that CD sent some time ago and would like to publish the entomological observations in it.

Encloses Fritz Müller’s letter.

Is exhibiting butterflies in which variations in the female show a finely graded series. Believes dimorphism can be explained by the selection of the extremes of such a series and the consequent extinction of the intermediates.

Would like to see the Kosmos article.

Is considering producing a translation of August Weismann’s essays.

Comments on Wallace’s paper on the colours of animals and plants [Macmillan’s Magazine 36 (1877): 384–408, 464–71].

Wishes to borrow third part of Fritz Müller’s article on sexual selection in butterflies [Kosmos 2 (1877–8): 218–24].

Is forwarding material on stridulation, including Prof. Wood-Mason’s paper ["Note on Mygale stridulans", Trans. R. Entomol. Soc. Lond. (1877): 281–2], which should interest CD.

Returns Kosmos.

Thanks CD for permission to use Fritz Müller’s last letter, which contains new observations.