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Darwin Correspondence Project

To J. D. Hooker   4 December [1854]

Down Farnborough Kent

Dec. 4th

My dear Hooker

I solemnly vow I will not write again for an enormous age,—not even if you were to say that you had nothing to do, & liked answering never-ending, nowhere-going questions.— But I want you “twice awfully” (as Lenny says)1 to ask Mr. Bentham (whom I fancy you see often) whether he excluded from his list of aberrant genera, genera simply because they contained many species; for I am staggered at the fewness of the species; & cannot but fear that he has done so.2

I see that he has taken indifferently genera single in their orders, & genera when there are are many. This, I believe, for my object is the best & only plan; viz to take a form, (& leaving it indifferent whether to call such form a generic, or Family or order type)3 & see whether on this form there are as many species, as on an average there in genera; for if in these aberrant groups, there are fewer species than in average of the ordinary genera, then will a fortiori be far fewer than on an average in the Families orders &c.;—there being in each Family an average of some hundred species. Do you agree with this way of putting my point? I very much fear that Mr. Bentham must have excluded genera, merely from containing many species; if he excluded any, because he thought that such groups of species ought to be broken into many genera, the case will be different.— Please see what you can find out, for as it now is, I darenot trust at all to list.

With respect to your speculation on effect of splitting Australia; I agree very far with you; but I think that you somewhat underrate the effect on all the species of such a movement or irruption as you suggest.

Will you tell me, (have patience, for I really will be merciful to you for a good long time) whether you have anywhere published or intend publishing (& where?) your belief that all Aquilegias’ are one species. Do you feel pretty confident, or was it mere passing remark? I feel interest on account of great fertility of the forms together.

I shd be very glad to hear that you had worked & published your opinion on this genus.—4

I have just read your fine tribute to the character of poor Forbes in Gardeners’ Chronicle.5

I hope that you are comfortably settled in your new House; & I will answer for it that Mrs. Hooker has done wonders in arranging everything to perfection.

Ever yours | C. Darwin

Here is a bore, I doubt whether we shall be able to come in to London for 2 or 3 weeks this winter from extreme difficulty, as 3 House-Agents assured me, in getting Houses for very short periods.—6


Leonard Darwin, who was 4 years old (see Correspondence vol. 4, Appendix III).
George Bentham had sent CD a list of eighty ‘anomalous genera’ (see letter from J. D. Hooker, [15 November 1854]).
See CD’s memorandum attached to letter from J. D. Hooker, [15 November 1854], n. 4.
Gardeners’ Chronicle and Agricultural Gazette, no. 48, 2 December 1854, pp. 771–2: ‘[Forbes] was beloved and admired beyond any natural historian of his day.’ (p. 771).
In the event, the Darwins did obtain a house at 27 York Place, off Baker Street, from 18 January to 15 February 1855 (‘Journal’; Correspondence vol. 5, Appendix I).


Is Bentham’s list of aberrant genera biased by exclusion of genera with many species?

JDH’s belief that Aquilegia varieties are one species is consistent with their great interfertility.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 114: 159
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1610,” accessed on 22 April 2018,

Also published in The Correspondence of Charles Darwin, vol. 5