Sorry that his health prevents him attending a meeting to honour Adam Sedgwick.

CD has discovered correspondent intends to present a petition to the House of Commons on which CD’s is the sole signature. Asks that his name be erased unless other signatures are added.

Does not understand TM’s views on sex and vitality.

Agrees no real "essences" in genera, only broken groups of species.

Thanks WP for his accounts of sagacity of dogs. "I can believe almost anything about them."

Responds to AN’s observations on sense of smell in cats and dogs.

Sends £10 subscription for James Murie.

Thanks RM for note on ocelli.

Thanks for Indian [Medical] Gazette. Comments on article.

Reports that he has not received JSBS’s book on histology and physiology [Sanderson ed., Handbook for the physiological laboratory (1873)], which Edward Emmanuel Klein told CD’s son was to be sent. He asks for information so that he may thank Dr Klein. [Klein and Michael Foster were co-authors with JSBS.]

He has returned the Gazette to Dr T. L. Brunton. [See 8825.]

Advertising a testimonial for James Murie.

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".

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.

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.

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.

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."

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