Encloses a testimonial for GWC [see 6162]. Feels himself poorly qualified to give a testimonial for a botanist and apologises for his brevity.

Asks about the ratio of male to female Lepidoptera.

Encloses grass from locust dung sent from Natal. Asks for name of grass.

Thanks for information on sex ratios of Lepidoptera.

Agrees that entomologists have best means of proving derivation of species.

JDH too severe on Duke of Argyll.

Pities JDH on [BAAS] address [see 6099]; Huxley feels JDH will do well and will not pity him.

Thinks Huxley will give an excellent and original lecture on geographical distribution of birds.

Has been working hard on sexual selection and correspondence about it.

Mignonette is sterile with its own pollen but any two distinct plants are fertile together. It is utterly mysterious and not even Pangenesis will explain it.

On Lyell’s book [Principles, 10th ed.].

Wallace’s wonderful cleverness, but he is not cautious enough. CD differs from Wallace on birds’ nests and protection.

A. Murray’s miserable criticism of Wallace [J. Travel & Nat. Hist. 1 (1868): 137–45].

Cannot judge GWC’s fitness for the Botanical Chair at Oxford. But CD appreciates his work, particularly that on spontaneous generation [Proc. R. Soc. Lond. 13 (1863–4): 313; 14 (1865): 178].

Did not know of complex change of plumage. From WBT’s letter, CD thinks six weeks to two months old is the best period. Sends details of breeds and other particulars.

Sends some questions on secondary sexual differences of fishes [missing], which he hopes AG will look over.

Invites AG to come to Down.

Encloses queries on sexual differences and nest-building habits of fish.