From Robert Caspary 17 December 1876
Koenigsberg am Rh
17.12. 1876
Dear Sir,
I feel very much obliged to you for your kind present: The effects of cross & self fertilisation, which I certainly shall read with the greatest interest1
What a curious thing it is, that your son Francis found nectaries on Pteris aquilina, certainly it is out of question that in this case they have the destination of alluring insects for fertilisation.2
I shall wright to Dr Hooker on account of the repeated introduction of Euryale, of which nothing is known. as also on the case, which he asserts, that the same stock of Victoria bears 2 flowers at the same time.3 I heard only once of this from Mr Linden, the famous gardener at Brussels, who told me that at Brussels once the Victoria in the Zoological garden had two flowers at a time, one going off the other opening, but I thought no more of it, than I though of that figure of the Victoria regia in Chatsworth once published in the London illustrated news as also in Flora des terres (there even by Planchon), on which three flowers, all opened, are represented as flowering at the same time at the same stock.4 That is fancy. But even if Mr Linden was right, as regards the crossing of one flower by the pollen of the other, two flowers open at the same time have no effect, because the one, the younger is perfectly closed, no insects ever will be able, at least not ours, to carry the pollen from the older flower, which certainly will also have the anthers covered with the parastamens,5 to the younger, or rather to its stigmatic disc, which is as yet not accessible, but will be so only the next night after.
With Euryale it is the same thing. I have seen as of Victoria hundreds of flowers of it, but all single. Only in Autumn if all possibility of bringing seed is over, because the necessary warmth is gone, from the beginning of September in this country, two, three or even 4 flower may be seen over water on the same plant, and even partly opened at the same time, but this has nothing to do with the question on hand.
I am sorry to say I got this year no seed from both stocks of Euryale which I had, not because I believe your theory right, but because in spring all seedlings perished repeatedly by a fungus (a Saprolegnia6 probably), so I got only towards the middle of May two good seedlings, these began to flower towards the end of August, but then it was too late in the year, for bearing seed here. Last year I had the largest plants of Euryale, I ever saw; the leaves had 4 feet in diameter. I have still seed of 1875, but these are not quite safe for procuring plants in 1877 and I shall probably be obliged to get seed from some other garden.
Believe me, dear Sir, yours most truly and faithfully | Rob. Caspary
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 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.
Jackson, Benjamin Daydon. 1900. A glossary of botanic terms: with their description and accent. London: Duckworth & Co. Philadelphia: J. B. Lippencott Company.
Summary
Thanks for copy of Cross and self-fertilisation.
Francis Darwin’s observation of nectaries in Pteris is most curious.
Doubts cross-fertilisation in the rare cases of two flowers on the same stalk in Victoria and Euryale.
Letter details
- Letter no.
- DCP-LETT-10726
- From
- Johann Xaver Robert (Robert) Caspary
- To
- Charles Robert Darwin
- Sent from
- Königsberg
- Source of text
- DAR 161: 123
- Physical description
- ALS 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 10726,” accessed on 28 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-10726.xml
Also published in The Correspondence of Charles Darwin, vol. 24