Sends CD ch. 2 of his book [The naturalist on the river Amazons] for suggestions, having accepted CD’s recommendations concerning ch. 1.

Effects of climate on dress in ch. 1 similar to, but independent of, notions expressed by CD in his Journal of researches [p. 381].

On geology, book deals with distribution and theory of deltas of the Amazon.

Grieved to hear of CD’s illness; begs him not to give moment’s thought to his MS until health has returned.

Plans to exhibit mimetic butterflies at Linnean Society.

Has been in bad health and has just read HWB’s MS in the last two days. Praises the book; assured it will be successful. Offers to write to Murray. Hooker interested in conclusions on colour.

Thanks CD for returned MS and letter with its good opinion. Asks CD to write to Murray.

Encloses note from Murray, hoping it will be satisfactory. Murray is ready to see as much of MS as possible. Murray is considered honest but may be cautious, since HWB’s name is unknown to the public.

Writes that [Murray’s] terms are very favourable; has never heard of such terms offered for a first work. HWB can depend on fact that Murray is pleased with it [The naturalist on the river Amazons].

Thanks for information on domestic animals of Indians.

Glad Murray thinks well of MS of The naturalist on the river Amazons.

CD working on proofs of Orchids.

Invitation to visit; Hooker will be present. Gives directions to Down. Also plans to invite John Lubbock over for an evening.

Accepts CD’s invitation.

Discusses insects of south temperate S. America and New Zealand, especially with respect to the distribution and origin of Chilean Carabi, and has sent for a German monograph to learn about the eleven species he has found.

He refers to Chilean poverty in butterflies; scanty New Zealand insect fauna.

An analysis of south temperate insects is desirable, but the small English collections make him afraid to undertake it.

Thanks for letter and "valuable" extracts.

If S. American Carabi differ more from other species than do those from other distant locations (e.g., Siberia, Europe, etc.), CD agrees that difference would be too great to have occurred in the recent glacial age; CD also rejects independent origin. Plants seem to migrate more readily than animals. HWB should not underrate length of glacial period; CD also believes they will be driven to an older glacial period.

Sorry about news of British Museum – hopeless to contend against anyone supported by Owen.

CD dearly wishes HWB could find a situation in which he could give time to science.

Referring to conversation with Lyell, CD is certain that there was a Miocene glacial period.

Compliments HWB on the mimetic display at the British Museum. Those at the Museum readily accepted HWB’s "doctrine".

Was shown genital organs of closely allied Chrysomelidae.

Albert Günther is candidate for position at Museum.

Miocene glacial period a remarkable discovery; if it is true, enlargement of Tertiary period necessary.

Received German monograph on Chilean Carabi that does not answer where isolated species came from.

HWB finds genital modifications of Chrysomela strong support for the theory.

Thanks for copy of Orchids.

Encloses a question [missing] concerning language [from Hensleigh Wedgwood].

Sends answer to Wedgwood’s query

and is sorry to hear CD is again unwell.

His book is progressing very slowly.

Asks that CD not make use of any of the facts about generative organs in beetles for he finds "such a chaos of statements" that facts are not to be depended upon.

Asks for news of HWB and his book.

There has been sickness in CD’s family; one of the boys [and Emma] had scarlet fever.

Has had a letter from Edwin Brown of Burton who is working on classification of Carabi.

Still working on book and has completed 620 out of 700 pages.

Rewrote memoir [on mimicry in Amazon Lepidoptera] for Trans. Linn. Soc. Lond. [23 (1862): 495–566].

Edwin Brown, HWB’s earliest naturalist friend, will have a hard time classifying Carabi as he is unable to travel.

Thanks for last note. Assures HWB that all writers have problems similar to his.

Plans to inquire at Linnean Society for HWB’s paper.

His family, including Mrs Darwin and Leonard, are now well.

Just finished HWB’s paper ["Contributions to an insect fauna of the Amazon valley", Trans. Linn. Soc. Lond. 23 (1862): 495–566], one of the most remarkable he has ever read. Found mimetic cases and connection of facts marvellous. Finds equally important the facts on variation and segregation of complete and semi-complete species. Questions whether insect mimicry is not due to small size and defencelessness. Criticises title of paper. Mentions that Wallace will appreciate it.

Gratified by CD’s approval of paper which was also praised by Hooker and Wallace. Only cares for one other opinion, that of C. Felder of Vienna. He finds ordinary entomologists are not scientific men. Asks for more criticisms; desires to publish paper in a widely circulating journal to advertise his book.