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.

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

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.

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.

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.

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.

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.