Comments on SB’s book [The fair haven (1873)]. CD is struck by SB’s dramatic power – thinks he could write "a really good novel". Surprised at strength of case SB makes that Jesus did not die on the cross. SB’s identity will soon be universally known: Leslie Stephen knows he is the author.

The impossibility of conceiving that the universe arose through chance is the chief argument for the existence of God, but CD has never been able to decide whether this is an argument of real value. Safest to believe that the subject is beyond man’s intellect, "but man can do his duty".

Comments on article ["Perception and instinct in lower animals", Nature 7 (1871): 377–8].

Explains his contention that "many of the most wonderful instincts have been acquired, independently of habit, through the preservation of useful variations of pre-existing instincts". Cites examples: sterile workers of several species of social insects have acquired different instincts; movements of tumbler pigeons. Speculates that "many instincts have originated from modification or variations in the brain".

"The following fact with respect to the habits of ants, which I believe to be quite new, has been sent to me by a distinguished geologist, Mr J. D. Hague [see 8788]; and it appears well worth publishing."

Anxious to have GHD come home because of his poor health. Recommends Huxley’s physician (Andrew Clark) – an advocate of milk diet.

Has sent JDH’s letter to Nature ["Perception in ants", Nature 7 (1873): 443–4].

Sons recall kindness received from JDH and others in America.

Thanks for present of

Wants to discuss raising a testimonial fund for Huxley and whether Huxley would stand this.

Thanks TD for catalogue of his Cretacean fossils.

Regrets he cannot visit Brighton.

Discusses the arrangements being made to present a gift to Huxley [see 8872].

CD will write to William Spottiswoode about the fund for Huxley. CD is raising his subscription to £300. "We have done a good day’s work … [it] gives me a higher opinion of human nature than I had before, though I am not one of those who think lowly of mankind."

Hopes that Charles Lyell has enjoyed his excursion.

Sends JT the list and amounts subscribed for Huxley. It will probably amount to £1800. He will write to Huxley and use every argument he can to make him accept.

CD did not bring any tortoises back from the Galapagos. There may be specimens at the Military Institution in Whitehall.

Sorry AG was unable to lunch with the Darwins during their stay in London.

Thanks AWM for "Comus" and an abusive New Orleans Mardi Gras newspaper editorial; he cannot tell from the "wonderful mistakes" whether the writer is "witty, ignorant, or blunders for the sake of fun".

Sends to Pantlludw [North Wales] bottle of formic acid. FD and Amy [Darwin] can search for spawn. If found, keep in two basins and add 6 drops of acid to one and look for differences.

Discusses error in CD’s calculation of natural increase of elephants.

Includes extract from Origin.

"Try only 1 or 2 drops of Formic A[cid]."

Thanks LB for his essay on local biology.

CD with much care and discomfort is now able to work a few hours almost every day.

Photographs sent by JC-B show great power of acting.

David Ferrier’s researches sound wonderful. Does he believe that he excites an idea and this leads to the movement, or that he acts directly on the motor nerves?