Comments on the great extent of variations and on the acknowledgment of the new idea of greater female variety.

Expresses belief that the glacial period did affect the tropics, though HWB’s arguments have confounded him.

Poses a series of questions concerning sexual selection.

CD urges HWB to write on his travels;

asks for facts on domestic variations;

is pleased by HWB’s acceptance of the theory of sexual selection.

He still believes in migration from north to south during glacial age.

Hopes Bates will publish a paper on mimicry.

Recommends publisher for HWB; admires J. van Voorst but suggests Murray.

In reply to HWB’s letter [missing], comments on neuters and mimicry.

Thanks HWB for information on Volucella, although he does not know when he will use it.

Is glad HWB is beginning his book.

CD is beginning work on his orchid book.

Thanks HWB for references.

Praises his paper ["Contributions to an insect fauna of the Amazon valley", read before Linnean Society, 21 Nov 1861, Trans. Linn. Soc. Lond. 23 (1862) : 495–566] which solves "one of the most perplexing problems which could be given to solve".

Discusses the difficulties of writing and expresses disappointment at Wallace’s book [Travels on the Amazon (1861)].

Praises MS of first chapter of HWB’s book [The naturalist on the river Amazons (1863)]. Suggests he give common names and make comparisons to familiar English species to help readers. Suggests a few changes. Will speak strongly to Murray about publishing whenever HWB is ready.