Thanks CdeC for his Mémoire sur la famille de Piperacées [1866]. Regrets he has not sufficient knowledge of botany to understand all the points discussed.

Sorry his health prevented his attending [Botanical] Congress and meeting CdeC’s father.

Has not seen K. E. von Baer’s paper ["Über Papuas und Alfuren", Mem. Acad. Imp. Sci. St.-Pétersbourg (Sci. Nat.) 8 (1859): 269–346], but has read extract.

Knew of case of hairy and toothless family through John Crawfurd, Journal of an embassy from the Governor-General of India [2d ed. (1834)].

Working on causes of variability.

Has read abstract of JL’s paper ["On the present state of archaeological science", Athenæum 21 July 1866, pp. 79–82] and praises it.

Answers JDH’s questions on connection of SE. England and continent,

on the effect of breaking the Isthmus of Panama,

and on Madeira flora as remnant of Tertiary flora.

Cautionary remarks for JDH on his "Insular floras" speech, designed to strengthen case of "occasional migration" theory.

Comments on pigeon and poultry woodcuts.

Observations and queries on poultry.

Thanks for AG’s trouble about new edition of Origin.

Will be printing his new book [Variation] at the end of the year.

[Forwarded by AG, with covering note, to Mr Fields of Ticknor & Fields.]

CD defends his view of land birds on St Helena.

Explains why he would not expect American plants on the Azores.

It makes him miserable that he and JDH look at everything so differently.

Admits that occasional transport is not a well-established hypothesis but believes it more probable than continental extension as an explanation for the stocking of islands.

Thanks WBT for help with woodcuts [for Variation].

Has returned WBT’s curious feathers.

Asks readers to examine the flowers of Oxalis bowei to observe where the summits of the branching stigmas stand with respect to the two sets of anthers. In CD’s plants the stigmas stand beneath the lower anthers, but he believes two other forms exist: long-styled and mid-styled. Would be grateful for flowers of these types so he can fertilise them and obtain seed.

Describes the difficulties of crossing papilionaceous flowers. Believes the lack of success is a consequence of the need for early castration and successive applications of pollen on the stigma. Gives details of a method he has used to cross such flowers successfully.

Will be glad to see JDH at Down.

Comments on sheet of EH’s Generelle Morphologie [1866]. In emphasising divergence of character EH shows his clear understanding of CD’s views. It was years before CD saw necessity of divergence.

Interested in Carl Claus [Copepodenfauna von Nizza (1866)].

On various subjects: Dana’s misquotations,

H. J. Clark’s book Mind in nature [1865],

BDW’s Cynips experiments, galls,

Balbiani’s paper on aphids ["Sur la reproduction et l’embryogénie des pucerons", C. R. Hebd. Acad. Sci. 62 (1866): 1231–4, 1285–9, 1390–4].

Claus and other Germans testing CD’s views of variability in common lower animals.

Thanks for observations on orchids.

FM’s paper on climbing plants [see 5146]; CD has received proofs.

Carl Claus’s pamphlet on copepods [Die Copepodenfauna von Nizza (1866)].

Family news. Describes [final] illness of Susan Darwin [d. 3 Oct 1866]. CD’s health better.

Making rapid progress on Variation.

Has heard of hybrids between moths mentioned by WDF.

Work on [4th] edition of Origin has delayed Variation.

Pleased by JDH’s success. JDH gives argument for occasional transport with perfect fairness.

W. R. Grove’s address [see 5201] good, but is disappointed that species part was so general.