To J. D. Hooker 5 July 1
My dear Hooker
I wrote this morning in tribulation about Tristan d’Acunha. The more I reflect on your antarctic Flora, the more I am astounded. You give all the facts so clearly & fully, that it is impossible to help speculating on the subject; but it drives me to despair, for I cannot gulp down your continent;2 & not being able to do so gives in my eyes the multiple creationists an awful triumph. It is a wondrous case,3 & how strange that A. Decandolle should have ignored it,4 which he certainly has, as it seems to me.
I wrote Lyell a long geological letter about continents,5 & I have had a very long & interesting answer;6 but I cannot in the least gather his opinion about all you continental extensionists; & I have written again beseeching a verdict.7
I asked him to send to you my letter,8 for as it was well copied it would not be troublesome to read; but whether worth reading I really do not know: I have given in it the reasons which make me strongly opposed to continental extensions.
I was very glad to get your note some days ago:9 I wish you would think it worth while, as you intend to have the Laburnum case translated, to write to “Wien” (that unknown place) & find out how the Laburnum has been behaving since that year: it really ought to be known.—10
The Entada is a beast;11 I have never differed from you about the growth of a plant in a new island being far harder trial than transportal, though certainly that seems hard enough. Indeed I suspect I go even further than you in this respect; but it is too long a story.—
Thanks you for the Aristolochia & Viscum cases: what species were they? I ask, because oddly these two very genera I have seen advanced as instances (I forget at present by whom, but by good man) in which the agency of insects was absolutely necessary for impregnation. In our British diœcious viscum, I suppose it must be necessary. Was there anything to show that the stigma was ready for pollen in these two cases? for it seems that there are many cases in which pollen is shed long before stigma is ready.
As in one Viscum insects carry sufficiently regularly for impregnation pollen from flower to flower; I shd. think that there must be occasional crosses even in an hermaphrodite Viscum. I have never heard of Bees & Butterflies, only Moths producing fertile eggs without copulation.—12
What a case of Aldrovanda!
I remember Decandolle, (the father) quotes it as wonderful case even in two rivers of Europe.13
With respect to Ray Soc. I profited so enormously by its publishing my Cirripedia, that I cannot quite agree with you on confining it to translations; I know not how else I could possibly have published.—
I have just sent in my name for £20 to Linn. Soc;14 but I must confess I have done it with heavy groans, whereas I daresay you gave your £20 like a light-hearted gentleman.
My dear Hooker | Ever yours | C. Darwin
Wollaston speaks strongly about the intermediate grade between two varieties in insects & mollusca, being often rarer than the two varieties themselves.15 This is obviously very important for me, & not easy to explain. I believe I have had cases from you. But, if you believe in this, I wish you would give me a sentence to quote from you on this head. There must, I think, be a good deal of truth in it; otherwise there could hardly be nearly distinct varieties under any species, for we should have instead a blending series as in Brambles. & Willows.—
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.
Please cite as
Darwin Correspondence Project, “Letter no. 1919,” accessed on 31 August 2016, http://www.darwinproject.ac.uk/DCP-LETT-1919