Has just finished Origin. CD has demonstrated a true cause for the production of species.

CD has loaded himself with unnecessary difficulty in adopting natura non facit saltum.

Murray has sold out Origin; wants a new edition immediately.

Asks THH to check whether Geoffroy de St Hilaire is correct [form of name].

Would be grateful for THH’s impressions on the truth of natural selection.

THH’s letter about the Origin makes CD feel like a Catholic who has received extreme unction. Can now sing nunc dimittis. Had determined to abide by judgment of Lyell, Hooker, and THH.

Problem of how variations arise at all troubles him also.

Rejoices over THH’s lecture ["On species and races, and their origin", 10 Feb 1860, Not. Proc. R. Inst. G. B. 3 (1858–62): 195–200] to be given at Royal Institution. Offers pigeon illustrations.

Adam Sedgwick has sent a "slashing" letter [2548] about Origin.

Sends references for materials useful for THH’s lecture.

Breeding and crossing. Pigeon fanciers.

Responses to Origin: A. C. Ramsay, Charles Kingsley, Quatrefages de Bréau.