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 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)].