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Darwin Correspondence Project

From Thomas Meehan   1 July 1877

St Clare, Ryde, I. of Wight

July 1st. 1877

Charles Darwin Esqre

My Dear Sir,

I beg to send you with this a copy of a review of your works, which appeared in the Penn Monthly since I left America, and which has just been mailed to me.1 I should have sent it to you with more pleasure had I been able wholly to agree with you,—for I do not know that I am indebted to anything so much as your works for the pleasure I have derived in the life studies of plants.

There is however one thing which has much pleased me in a perusal of your last work. It is of course known to you, that much of the work on “Self fertilization and cross fertilization”, which has been done in America, though not nominally, yet has been really prompted by my own,—that is has been the work of friends who thought I was extreme in my views as regards those which you hold. I see now why you thought my Detroit paper extravagent in its presentation of views I was opposing—2 You did not know how much further your friends had advanced than yourself. It is now clear that I am much more in accord with you than with some of your friends. One whom I am proud to call my friend also, Prof. Asa Gray, with that generous candor which I have always found in him when thoroughly convinced, has written to me that he is now satisfied that there is far more self fertilization among flowers than he had supposed until your book appeared. There is no difference between us now except as to the proper interpretation of the facts of cross fertilization.3

I was interested in noting here, where Yucca gloriosa is flowering freely, that it is visited by Honey bees, and more abundantly by other insects which come out of the flowers when the plant is jarred,—but are too far away from the eye for identification. It does not mature seed here,— it seems as if only the Pronuba Yuccasella can fertilize the Yucca, but, as you are no doubt aware, the Pronuba fertilizes the flower with its own pollen,—and it seems to me a great mystery why the plant should not be arranged to use any itself, and not be necessitated to have insect aid in the use of its own pollen.4

I leave England again for America by the Indiana from Liverpool for Philadelphia 18th. of July,—but shall be in London (care of Editor of Garden)5 during the week 6th–13th. In my arrangements I should have planned a brief call on you, but feel how much you must be impeded in your labors by visitors and correspondents, as I am when at home,—and so I have brought myself to be satisfied with the infliction of this review and accompanying letter on you.

Very truly Yours | Thomas Meehan


There is an offprint of Meehan’s review of Cross and self fertilisation (‘Darwin on the fertilization of flowers’; Meehan 1877), from the June 1877 issue of Penn Monthly, in the Darwin Pamphlet Collection–CUL.
Meehan had read a paper, ‘Are insects any material aid to plants in fertilization?’ (Meehan 1875), at the 1875 meeting of the American Association for the Advancement of Science in Detroit. In this paper, Meehan argued that insects played a limited role in plant fertilisation and that self-fertilised plants were as vigorous as and more productive than those dependent on insect aid. CD had feared that Meehan had travestied the views of Hermann Müller and John Lubbock (see Correspondence vol. 23, letter to Thomas Meehan, 3 October 1875; see also ibid., letter from Hermann Müller, 23 October 1875).
Meehan argued that cross-fertilisation was not an adaptation that increased the vigour and reproductive success of plants, but a precursor to extinction (Meehan 1877). Gray reviewed Cross and self fertilisation in the American Journal of Science and Arts (A. Gray 1877c), drawing attention to self-fertilisation as a back-up strategy even in cross-fertilised species.
Yucca gloriosa, the moundlily yucca, is native to the south-eastern US. Pronuba yuccasella is a synonym of Tegeticula yuccasella, the yucca moth. On pollination and mutualism in the yucca moth, see Pellmyr et al. 1996.
The Garden, a horticultural magazine published in London, was edited by William Robinson.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Cross and self fertilisation: The effects of cross and self fertilisation in the vegetable kingdom. By Charles Darwin. London: John Murray. 1876.

Meehan, Thomas. 1875. Are insects any material aid to plants in fertilization? Proceedings of the American Association for the Advancement of Science 24: 243–51.

Meehan, Thomas. 1877. Darwin on the fertilization of flowers. Penn Monthly, June 1877, pp. 463–71.


Credits himself with stimulating most of the American work on plant cross-fertilisation. Sends his review of Cross and self-fertilisation [in Penn Monthly (June 1877)]. Suggests CD, A. Gray, and TM now agree on the extent of self-fertilisation in nature.

Letter details

Letter no.
Thomas Meehan
Charles Robert Darwin
Sent from
Source of text
DAR 171: 112
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 11028,” accessed on 23 January 2022,