Podostemaceae flowering under water.

Sends JDH part of MS for chapter 3 of Natural selection ["Possibility of all organic beings crossing"] to be corrected and returned.

JDH’s report of Podostemon flowering cleistogamously under water in Bengal.

[Copious revision by JDH.]

His observations on Subularia: has never seen it in flower in the air.

Questions JDH on separation of sexes in trees in New Zealand flora.

Cites cases of leguminous plants whose cleistogamic flowers produce more seed than perfect flowers. [See Forms of flowers, p. 326.]

Thanks GB for information on apetalous flowers. "The whole order [Leguminosae] will remain my detestable enemies."

Is glad WBT is willing to describe the poultry CD can acquire. Sir James Brooke promises Borneo fowls.

CD is collecting all the evidence he can on natural crossing of varieties of plants. Asks readers of Gardeners’ Chronicle to give evidence "showing either that Leguminous crops, when grown close together do sometimes cross or on the other hand that they may invariably be grown close together without any chance of deterioration".

He is steadily and very hard at work on "Variation" [Natural selection] and finds the whole subject "deeply interesting but horribly perplexed".

Has done New Zealand flora calculations. Results support CD’s theory of necessity of crossing. Trees tend to have separate sexes.

Agassiz has informed him that the mice and rats of Mammoth Cave are American in type.

Alludes to CD’s doubt of the principle that "progress of life on the globe is parallel with the development in different tribes". Outlines his own ideas on the "unfolding of the type-idea" and its "parallelism with the law of development in the embryo".

Thanks her for kindness. Announces, "We have now half-a-dozen Boys" [Charles Waring Darwin, born 6 Dec].

Grateful for Siebold’s wonderful facts [C. T. E. von Siebold, On a true parthenogenesis in moths and bees (1856), trans. by W. S. Dallas (1857)].

Vitality of spermatozoa.

Hybridisation of bees. Bees are in one respect his greatest theoretical difficulty.

CD still convinced about the relation of cement receptacles and ovarian tubes [in Crustacea].

Birth of C. W. Darwin.

Writes of arrangements for the end of the school-term.

Condition of Emma and the new baby [C. W. Darwin].

CD is convinced of relation between separation of sexes and tree-habit.

Recent hard blows against crossing theory.

CD long tormented by land molluscs on oceanic islands; found transport possible experimentally.

Informs CD that the "dishonest mollusks" were collected in May 1855 in Porto Santo. Describes some Madeira species. Though believing in "species" more and more, these may be "mere insular modifications".

Pleased by what THH says on cement glands and organs in higher Crustacea. Content to be moderately right.

Hopes THH will dissect the Conchoderma.

Asks for cases of organs in which there is no apparent transition from other organs or in which transition can be shown in an unexpected way and for instances of odd and inexplicable connections between parts, such that if one part varies the other varies also.

Informs CD that in his experience with peas he has never found the seed to deteriorate.

Thanks for sending paper on geological development (Dana 1856). Discusses infertility of species. Discusses first part of Asa Gray’s paper (A. Gray 1856–7). Thanks for note on the Cave Rat. Discusses a new species of fossil cirripede, in the genus Chthamalus. Explains his interest in pigeon breeding.

Asks TD about variation among brachiopods.