Asks CD to send W. R. Grove titles and place of publication of the Müller [Für Darwin (1864)] and Walsh (Walsh 1864–5) papers he referred to in his address [BAAS lecture at Nottingham, see 5135].

Thanks JBEB for Papaver seeds. Has long wished to see some of the closely allied subspecies and hopes to make some crossing experiments with them.

William asks what to do about a complication in settling Aunt Catherine’s estate.

Wishes to consult Fritz Müller on pharmacological matters.

Sends proof sheet on the mathematics of representation. Intends to print in full JH's letter to Mrs. Drummond. Has not yet received information regarding the measuring bars as T. A. Larcom is busy.

Thanks CL for copy of his "grand book" [Principles of geology, 10th ed., vol. 1 (1867)]. Congratulates him on additions.

Mentions visit to E. A. Darwin.

Encloses note for Mr Corbet.

Gives observations on orchid ovules ripening long after blooming.

Infertility with own pollen sometimes does and sometimes does not indicate dimorphism; gives observations on Ximenia, Eschscholtzia and Oncidium flexuosum.

Describes some striking seeds eaten by birds,

and some new dimorphic species.

Variation in Thillia.

Confirms CD’s suspicion that the lancet-fish [Amphioxus] lives in competition with invertebrates: it shares its habitat with a similar-looking Ophelia, which is quite unlike other annelids, just as the lancet-fish is unlike other fishes.

Informs JH that his comments against sending a major telescope to India were decisive [see JH's 1866-8-11 & 1866-9-4]; biggest cost impediment was salary of observer.

Supports G. W. Kitchin's request that JH write treatise on inductive logic for benefit of Oxford students.

Lyell’s volume [Principles, 10th ed.] received.

"We must now keep him straight anent origin and development."

Some of Spencer’s new part is interesting but much is dull and ponderous.

Huxley’s Elementary physiology [1866].

Has finished his New Zealand manual [Handbook of New Zealand flora (1864–7)]. New Zealand flora [and past geological conditions] suggest islands were once connected.

Speculates on the total amount of living organised matter on the globe, and whether it varies.

Balfour Stewart on sunspots.

Appreciates the receipt of volume one of the tenth edition of CL's Principles of Geology.

Is tempted to cite Mr Zurhorst’s case.

Hopes to send pigeon and fowl MS [of Variation] to press in a fortnight.

Is sending some plants and seeds to JDH.

Thanks Mrs Hooker for telling him of a life of his grandfather [Erasmus Darwin] of which he had not heard.

No summary available.

Maintains that a first class refractor is not needed at Masouri in India [see ES's 1866-9-4]. No special characteristics there justify the great expense of such a project.

Discusses current debate over placement of telescope in India. Discusses various possibilities for telescope.

Clarendon Press plans to publish series on logic. Invites JH to write treatise on inductive logic. Expect letters on this from John Phillips and Bartholomew Price.

Acknowledges receipt by R.A.S. of papers relating to William Herschel's observations of double stars.

Sends his autograph.