Is glad MTM is going to experiment on Passiflora.

Is grieved to hear that John Scott has been inaccurate but cannot think he recorded, in his paper, experiments that he never made [see 4485].

He has finished MEW’s work on hybrid willows [Die Bastardbefruchtung im Planzenreich (1865)] and sends his thanks. The extreme frequency of hybrid willows is new to CD, and he finds the explanation of their numbers in certain locations ingenious.

Comments on the criticism of Gärtner’s view of reversion

and the differences between MEW and Naudin.

CD now has doubts regarding his own view that hybrids are sterile from not being perfectly accommodated to their conditions of life.

Requests all parts of Transactions due him.

Inquires about body of Porto Santo rabbit which has not arrived.

Falconer’s death haunts him. Personal annihilation not so horrifying to him as sun cooling some day and human race ending.

His health has been wretched.

Masters has written his agreement with CD’s "Climbing plants".

CD sends thanks for feather of the Gallus.

The rabbit arrived safely, but unfortunately the entrails had been removed; if ADB catches the other one, CD would like it sent unmutilated.

Darwin compliments ARW's papers published in the Proceedings of the Zoological Society of London and in the Journal of the Royal Geographical Society on geographical distribution in the Malay Archipelago.

Hildebrand has sent copy of his paper on Pulmonaria in Botanische Zeitung.

How much should CD contribute to Falconer’s bust?

Oswald Heer on alpine and Arctic floras.

A. R. Wallace on geographical distribution in Malay Archipelago.

Lyell’s new edition of Elements. Wishes someone would do a book like it on botany.

Belated thanks to CL for copy of Elements. Praises CL’s work. Notes especially Atlantic continents, the Weald, the Purbeck beds, glacial action, and the formation of lake-basins.

Also mentions account of Heer’s work

and CD’s disagreement with J. D. Forbes.

Suggests that CL have Murray print a two-volume edition [of the Elements].

Wants his fowl MS.

Will shortly return WBT’s skulls.

Asks for return of page about pigeon crossing.

Asks for WBT’s help in arranging for woodcuts to illustrate pigeon chapters of Variation.

Is pleased to hear of Dr Heine’s interest in Origin. Questions whether Dr Heine’s law of inheritance can be demonstrated.

Thanks for Thomson’s and JDH’s views on Scott’s paper. Will send it back with advice and explanations.

Has heard from Mr Pennell, and written to say too ill to see him. Would like to hear about skin between toes of otter hounds in comparison with other hounds.

Interested by HD’s information on aperea; CD had concluded that it was not the progenitor of domestic guinea-pigs.

Is unsure what HD means by "stock-dove"; properly this is Columba oenas and the domestic pigeon is C. livia.

Suggests that the Zoological Society might arrange for some specimens [unspecified] to be supplied from the Gardens.

Mentions Miss Buckley’s information on roosting in trees [see Variation 1: 181 n.].

Refers to Duke [of Argyll] and his Lamarckian view of change.

Roosting habits and behaviour of pigeons in Egypt.

Criticises Herbert Spencer’s works.

Has finished Elements; comments on Laurentian stages.

Remarks on his health

and forthcoming work [Variation].

Thanks for fact about the buffalo diving.

Asks whether the animal was a Bos or a Bubalus.

Comments on BDW’s papers ["On certain entomological speculations of the New England school of naturalists", Proc. Entomol. Soc. Philadelphia 3 (1864): 207–49; "On insects inhabiting the galls of certain species of willow", ibid. 3 (1864): 543–644]; much is new to CD.

Asks about wide-ranging insect genera,

Rocky Mt. wingless insects,

willow hybrids,

galls,

and other subjects.

Arrangements for woodcuts for Variation.

WBT’s excellent article on crossing.