From Charles Lyell [before 20 November 1860]1
was ever returned.
I suspect that the Scandinavian flora was the first, then the Germanic & that the other subfloras got in by various geographical opportunities after the era of submergence or floating ice & when the larger part or the whole area within the 100 fathom line was land dry—
If you refer to DelaBeche’s map Geological Researches p. 1902 or Trimmer Quart. Journ. G. S. p. 293 vol. 9.3 see maps you will see that a low plain of land skirting the bay of Biscay & France & joining Ireland would when all within the 100 fathom line was dry land allow the Asturian plants to reach Ireland & if this happened when the emeral isle was nearly or quite separated from England it might explain why said southern species never got into England.4
Have you read Jamieson of Ellon in our last Quarterly Journal. 1860 p 349 &c.5 His 5 periods at p 370 can be made to square pretty well with Trimmers sketch maps above referred to.6 I shall give I think DelaBeches 100 fathom map, & Trimmer’s submergence map— But I am not prepared to give a third map but shall say that things were nearly restored to the status quo ante glacier after which came minor oscillations of level.7 What immense periods these within the glacial episode so brief a portion of the pleiocene!
Has Hooker or any one ever criticized E. Forbes’ Botanical migrations of his 5 floras in British Isles?8 I have not heard whether J. Hooker is returned from Syria.9
Phillips does not appear to me in glancing at his chapters to have taken hold strongly of any subject such as the age of the Amiens man or Natural Selection.10 He gives Sedgwick & others as authorities.11 In regard to progressive development he seems more cautious than formerly. Has he discovered that that theory tends in favour of transmutation!
Discusses the possibility of a land-bridge connecting Biscay with Ireland and the consequent occurrence in southern Ireland of Asturian plants which are absent from England.
Asks if Hooker or anyone has criticised Edward Forbes’ botanical migration of five floras in the British Isles ["On the connexion between the distribution of existing fauna and flora of the British Isles, and the geological changes which have affected their area", Mem. Geol. Surv. G. B. 1 (1846): 336–432].
Please cite as
Darwin Correspondence Project, “Letter no. 2902,” accessed on 17 January 2017, http://www.darwinproject.ac.uk/DCP-LETT-2902