To J. D. Hooker 28 February [1868]1
Down
Feb 28
My dear Hooker
I have been deeply interested by yr letter, & we had a good laugh over Huxleys remark which was so deuced clever that you cd not recollect it.2 I cannot quite follow yr train of thought, for in the last page you admit all that I wish, having apparently denied all, or thought all mere words, in the previous pages of yr note; but it may be my muddle. I see clearly that any satisfaction which Pan. may give will depend on the constitution of each man’s mind.3 If you have arrived already at any similar conclusion the whole will of course appear stale to you. I heard yesterday from Wallace, who says (excuse horrid vanity) “I can hardly tell you how much I admire the Chap. on Pan. It is a positive comfort to me to have any feasible explanation of a difficulty that has always been haunting me,—& I shall never be able to give it up till a better one supplies its place, & that I think hardly possible.” &c &c4 Now his foregoing double dashed words expresse my sentiments exactly & fully; tho’ perhaps I feel the relief extra-strongly from having during many years vainly attempted to form some hypothesis. When you or Huxley say that a single cell of a plant or the stump of an amputated limb, have the “potentiality” of reproducing the whole—or “diffuses an influence”5—these words give me no positive idea; but when it is said that the cells of a plant or stump include atoms derived from every other cell of the whole organism & capable of developement, I gain a distinct idea. But this idea wd not be worth a rush, if it applied to one case alone; but it seems to me to apply to all the forms of reproduction—inheritance—metamorphosis—to the abnormal transposition of organs—to the direct action of the male element on the mother-plant &c &c. Therefore I fully believe that each cell does actually throw off an atom or gemmule of its contents; but whether or not, this hypothesis serves as a useful connecting link for various grand classes of phyziological facts, which at present stand absolutely isolated.—
I have touched on the doubtful point (alluded to by Huxley) how far atoms derived from the same cell may become developed into different structure accordingly as they are differently nourished; I advanced as illustrations galls & polypoid excrescences.6
I have numbered, answered, & corrected yr queries as well as I can.7
It is a real pleasure to me to write to you on this subject, & I shd be delighted if we can understand each other; but you must not let yr good nature lead you on. Remember we always fight tooth & nail.
We go to London on Tuesday, first for a week to Q. Anne St, & afterwards to Miss Wds. in Regent’s Pk & stay the whole month, which as my gardener truly says is a “terrible thing” for my experiments.8
Newton told George at Cam. that Berthold Seemann wrote the Rev. in the Ath.9 & that he heard from Kingsley that Lewis did not write that in the Pall Mall—10
yours very affectionately | Ch. Darwin
[Enclosure]
Q. 1 I have altered this according to my view.11
Q. 2. I do not quite understand; I shd say “every reproductive cell contains atoms (gemmules) derived from every cell of the parent-organism; & these atoms after multiplying by self-division become diffused into every cell of the organism which is developed from the above reproductive cell.” (on Back)
Q. 3. I shd write “Any organism may develope any character from any ancestor however remote, but as explained in my Chap. there must be a limit to the number of atoms or gemmules which can be nourished in any being, so that there will be a limit to inheritance from ancestors very remote”
Q. 4 I see no reason to believe in this.
Q. 5. I thought a bud primarily consisted of a single cell; & this cell on my view will contain as many atoms or gemmules, derived from all the cells of the parent-organism, as are contained in the ovule together with a certain number of pollen-grains.
You shd observe that a single atom derived from any cell is not sufficient to develope this cell,— see my argument from the number of pollen-grains or spermatozoa requisite for fertilization I did not know that the superficial cells of Begonia & crytogams yielded buds more easily than deep-seated cells; this is very curious for most anatomists (ask Huxley if this is not so?) believe that the cells which form the spermatozoa are epithelial, & therefore homologically superficial.—12
Footnotes
Bibliography
Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.
Summary
Does not understand JDH on Pangenesis: on last page he appears to admit all that he regards as mere words on previous pages.
Wallace admires chapter on Pangenesis.
Pangenesis is a comfort. CD gains no idea from words like "potentiality" or "diffusing an influence"; atoms and cells give a distinct idea.
A. Newton told George that Berthold Seemann wrote the Athenæum review
and that Lewis [Lewes] did not write the Pall Mall Gazette review [see 5874].
Letter details
- Letter no.
- DCP-LETT-5951
- From
- Charles Robert Darwin
- To
- Joseph Dalton Hooker
- Sent from
- Down
- Source of text
- DAR 94: 55–7c
- Physical description
- LS(A) 5pp, encl 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 5951,” accessed on 10 October 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-5951.xml
Also published in The Correspondence of Charles Darwin, vol. 16