Thanks for new part of "Statistics".
Interested in disjoined species; do they tend to belong to large or small genera, and are they generally members of small families?
Is glad AG will tackle introduced plants; has noticed that the proportion of a particular family to the whole flora tends to be similar in introduced and indigenous plants.
Down Bromley Kent
My dear Dr
I must thank you for your new part of Statistics: if feeling
the most lively interest in reading it can make me worthy of receiving it, assuredly I
am worthy. I will not trouble you by specifying the many points which have particularly
struck me; but the note at p. 387 I must allude to, as I want to ask a
question which I think it cannot take 5 minutes to answer, namely to how many
genera the 49 species belong: as there are six species of Carex there cannot be
more than 44: I tried to go through list, but I
Your list of the Trees made my mouth rather water to know what proportion had sexes in some degree separated,—on which subject I wrote you a ridiculously long letter some weeks ago.
I am so glad that you are going to attack your introduced plants in the next
number: I may mention that two or three years ago I compared
the proportions of the British introduced species, to the native Flora & it was
in several cases ridiculously close: I then took your first Edition & did the same, but the proportions here were very different; but I
think this point wd
I have just looked at my old useless notes, & I see I made out in your Manual 206 introduced plants & of these Compositæ form 18 & so do (as I thought) your indigenous compositæ.—
In Britain from H. Watson's Cybele
I happened to stumble on these results first, & was inclined to think
something of them; but I suppose all was chance or errors. The standard proportion ought
to be, I shd think, that for world in same latitude, & not the
standard of the individual country. Though why I
With my sincere thanks & good wishes.—
Believe me | Your's most sincerely | Ch. Darwin
- f1 2089.f1The year is given by CD's acknowledgment of the receipt of the third part of A. Gray 1856–7 (see n. 2, below).
- f2 2089.f2The third and final part of A. Gray 1856–7 was published in the May 1857 issue of the American Journal of Science and Arts. CD's copy is in DAR 135 (3).
- f3 2089.f3Discussing species ‘of widely sundered habitation’, or the so-called ‘disjoined’ species of Alphonse de Candolle, Gray enumerated those species that ‘re-appear in Japan, the Himalaya, or some part of North Asia, but are not European’ (A. Gray 1856–7, p. 387). Dividing this group into two subclasses, the first being those common to north-west America and Japan and the second being those common to the Himalayas, Europe, and North America, Gray added the following note (A. Gray 1856–7, p. 387 n.), to which CD refers:
Out of 49 species belonging to these first and second heads, as many as 10 belong to monotypic genera, and 21 to genera of less than ten good species;—six of the species belong to the vast genus Carex;—on the whole rather militating against the idea that the geographical extension of species bears some proportion to the size of the genus they belong to.Part of CD's confusion is a result of an error Gray made in his note (see letter from Asa Gray, 1 June 1857).
- f4 2089.f4CD explained why he expected species with disjoined ranges to be found in small genera in letter to Asa Gray, 18 June .
- f5 2089.f5A. Gray 1856–7, p. 400. See letter to Asa Gray, [after 15 March 1857], and letter from Asa Gray, 1 June 1857.
- f6 2089.f6In the event, Gray was not able to prepare this paper. See letter from Asa Gray, 1 June 1857.
- f7 2089.f7A. Gray 1848.
- f8 2089.f8These notes are in DAR 46.2 (ser. 2): 38–41. CD discussed the naturalised plants of North America in Natural selection, p. 232 and n. 3, and in Origin, p. 115, but having retabulated his results using the second edition of Gray's Manual (A. Gray 1856a).
- f9 2089.f9Watson 1847–59. The calculations are in DAR 46.2 (ser. 2): 42–58. See Correspondence vol. 5, letter to J. D. Hooker, 13 April , for CD's earlier comments on these statistics.