Sends CD another piebald potato and a spray of holly, from Mr Fish, discussed in Gardeners’ Chronicle of 22 Jan [1869, p. 83].

On development of horns in merino sheep. Encloses reports from herdsmen he has approached.

Is trying to determine conditions governing whether or not a salmon will rise for a fly.

Is assembling apparatus of lenses and reflector to observe flower from opening to first shedding of pollen, and to determine whether fertilisation is by night- or day-feeders.

Will also examine reasons for absence of nectar in Polygala linaria.

Sends a paper on reproductive modes of Leptodera ["Organisation und Fortpflanzen von Leptodera", Schr. Ges. Beförd. Naturw. Marburg (1869)].

Criticises Ernst Haeckel’s work as too unripe and enthusiastic.

Asks CD for some specimens of cirripedes in pupal stage for a work in progress.

Answer to CD’s query as to whether horns on deer are for use or ornament. [See Descent 2: 252–3.]

Does not fact that characters important in systematics are often of no use, corroborate CD’s view that such characters, if not detrimental, may persist ad infinitum?

Social news.

On development of horns in fawns of fallow deer.

Believes Portuguese habit of removing tails of pointers is responsible for birth of some tailless dogs.

DF’s opinion of Gustav Jenzsch’s book [Mikroskopische Flora und Fauna (1868)]. Encloses extract of a letter from Ferdinand Zirkel also mentioning Jenzsch’s work.

Argues that [general variability] of species, not single variations or sports, is basis for modification and adaptation to new conditions.

No summary available.

Requests authorisation to translate Journal of researches into French.

A case of fighting in crabs (Portunus puber against Carcinus maenas) [see Descent 1: 332].

Corrects T. M. Brewer’s statement, cited in the Origin, that the American cuckoo never uses other birds’ nests. [See Origin, 5th ed., p. 266.]

Sends translation of Mr Steiger’s letter responding to question CD had asked about growth of horns of merino rams.

Lyell says CD is revising what he says about the Weald in the Origin. Asks CD to look at his subaerial denudation views in his book [Physical geology and geography of Great Britain, 2d ed. (1864)].

Gives consent, which is unnecessary because term of protection has expired, for French translation of Journal of researches.

Is at a loss to know how many copies of F. Müller’s Facts and arguments for Darwin to print.

The printer is ready for copy for a new "edition" of Variation. [Presumably another issue. 2d edition did not appear until 1875.]

Argues for great age of earth before the Cambrian period. Opposes measuring age from secular cooling. Opposes Sir William Thomson. Lyell’s error on secular cooling.

Thanks for Moseley citation ["On the mechanical possibility of the descent of glaciers", Proc. R. Soc. Lond. 17 (1869): 202–8].

In Edinburgh he feels out of touch with latest developments.

Believes that species or genus may have originated more than once from separate ancestors, i.e., polyphyletically.

Discusses relation of CD’s theory to religion. Has written popular account of CD’s theory in Dutch [Darwin en de Godsdienst (1869)].