Summary

Thanks AG for 2d part of "Statistics [of the flora of the northern U. S.", Am. J. Sci. 2d ser. 22 (1856): 204–32; 2d ser. 23 (1857): 62–84, 369–403].

Is glad AG concludes species of large genera are wide-ranging, but is "riled" that he thinks the line of connection of alpine plants is through Greenland. Mentions comparisons of ranges worth investigating.

Believes trees show a tendency toward separation of the sexes and wonders if U. S. species bear this out. Asks which genera are protean in U. S.

Summary

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.

Summary

Variability of naturalised plants.

Distribution of Arctic/alpine plant species.

Limits to the northern range of plants.

Summary

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

Summary

Troubled by JDH’s connection between Antarctic island flora and Fuegia, which CD sees as part of a general relation to southern circumpolar flora. Encloses list [not found] of plants from Tristan d’Acunha.

Summary

Delighted to hear that JD’s research is continuing. CD has heard that JD’s paper will at last be published. He is flattered by the form [as a letter addressed to CD] of communication. [See 1651a and 1819a, published in Phil. Trans. R. S. 146 (1856): 21–9 and Proc. R. S. London 8 (1856–7): 27–33.]

Summary

CD is unsure about JDH’s recommendation that he publish a separate "Preliminary Essay". It is unphilosophical to publish without full details.

CD will work for Huxley’s admission to Athenaeum.

Summary

Asks whether Allegheny Mountains are sufficiently continuous so that plants could travel from north to south along them.

Hopes AG’s work on geographical distribution is progressing, as he has questions on plants common to Europe which do not range up to Arctic.

Are intermediate varieties less numerous in individuals than the varieties they connect?

Summary

On the variety of species definitions prevalent among naturalists.

Summary

CD encloses letter from Asa Gray, although it is critical of JDH.

Role of struggle in forming species in retreat from advancing glaciers.

Summary

Asks whether the blind cave animals described by B. Silliman Jr [Am. J. Sci. 2d ser. 11 (1851): 332–9] belong to genera found only on the American continent.

On geographical distribution of Crustacea, CD asks whether northern genera sent species to the Southern Hemisphere or did southern genera send species north?

Does he know of any author who has described fossil trees in South Shetland Islands?

Summary

Arrangements for visit of Huxleys to Down on 26 Apr.

Summary

The responses to his queries on domestic variations are coming in from all over; believes he will make an interesting collection. At present concerned with rabbits and ducks.

Has told Lyell of his views on species and CL urges CD to publish a preliminary essay. Has begun to work on it, with fear and trembling at its inadequacies.

Summary

CD returns a letter from Wollaston.

Although opposed to the Forbesian doctrine [of continental extension] as a general rule, CD would have no objection to its being proved in some cases. Does not think Wollaston has proved it; nor can anyone until more is known about the means of distribution of insects – but the identity of the two faunas is certainly interesting.

His health is very poor and his "everlasting species-Book" quite overwhelms him with work. It is beyond his powers, but he hopes to live to finish it.

Summary

On geographical dispersal of plants. Would be interested in CJFB’s views on representative species and on his hypothesis of a mundane cold period, which CD cannot prove geologically, but thinks, if it explains many facts of geographical distribution, may be admitted as probable. Hooker and Alphonse de Candolle do not agree with him.

Summary

Will forward the Scandaroons.

Is crossing all his pigeons to see which are fertile.

Hopes WBT’s work on fowls’ skulls is not forestalled by T. C. Eyton who also has a grand collection of skeletons.

Summary

Thanks AG for the first part of his "Statistics [of the flora of the northern U. S.", Am. J. Sci. 2d ser. 22 (1856): 204–32; 2d ser. 23 (1857): 62–84, 369–403]

and for information on social and varying plants.

Would like to know number of genera of introduced plants in U. S.

Is surprised at some affinities of northern U. S. flora and asks for any climatic explanations.

Asks what proportion of genera common to U. S. and Europe are mundane.

Is glad AG will work out the northern ranges of the European species and the ranges of species with regard to size of genera.

Summary

Everything in Wallace’s sketch also appears in CD’s sketch of 1844. A year ago CD sent a short sketch of his views to Asa Gray. Can CD honourably publish his sketch now that Wallace has sent outline of his views? "I would far rather burn my whole book than that he or any man shd. think that I had behaved in a paltry spirit." Does not believe Wallace originated his views from anything CD wrote to him.

Summary

Rarity of intermediate varieties.

Variability of introduced plants.

Ranges of plants common to Europe and U. S.

Summary

Requests observations on pigeons.

Knew LE’s son [Thomas] and deplores his fate [accidental death in 1846].