CD forgets an author [CD himself in Coral reefs] "who, by means of atolls, contrived to submerge archipelagoes (or continents?), the mountains of which must originally have differed from each other in height 8,000 (or 10,000?) feet".
CL begins to think that all continents and oceans are chiefly post-Eocene, but he admits that it is questionable how far one is at liberty to call up continents "to convey a Helix from the United States to Europe in Miocene or Pliocene periods".
Will CD explain why the land and marine shells of Porto Santo and Madeira differ while the plants so nearly agree?
53 Harley St., Lond.,
June 17, 1856.
My dear Darwin
I wonder you did not also mention D. Sharpe's paper just published by which the Alps were submerged as far as 9000 ft. of their present elevation above the sea in the Glacial Period and then since uplifted again. Without admitting this you would probably convey the Alpine boulders to the Jura by marine currents and if so make the Alps and Jura islands in the Glacial Sea. And would not the Glacial theory as now very generally understood immerse as much of Europe as I did in my original Map of Europe when I simply expressed all the area which at some time or other had been under water since the commencement of the Eocene Period. I almost suspect the glacial submergence would exceed it.
But would not this be a measure of the movement in every other area northern (arctic) antarctic or tropical during an equal period—oceanic or continental for the conversion of sea into land would always equal the turning of much land into sea.
But all this would be done in a fraction of the Pliocene Period— The Glacial shells are barely 1 per cent extinct species?
Multiply this by the older Pliocene and Miocene epochs.
You also forget an author who by means of Attols contrived to submerge archipelagos (or
continents?) the mountains of which must originally have differed from each other in
height 8000 (or 10000?) feet, so that they all just rose to the surface at one level, or
their sites are marked by buoys of coral. I could never feel
sure whether he meant this tremendous catastrophe, all brought about by what
Sedgwick called “Lyell's niggling
operations” to have been effected during the era of existing species
of corals. Perhaps you can tell me for I am really curious to know. At all events he did
not I suspect go back as far as the faluns of Tourain for the commencement of the era of
the Coral Building spec
Now altho' there is nothing in my works to warrant the building up of continents in the Atlantic and Pacific even since the Eocene period yet as some of the rocks in the central Alps are in part Eocene I begin to think that all Continents and Oceans may be chiefly if not all post-Eocene and Dana's “Atlantic Ocean” of the Lower Silurian is childish (see the Anniversary Address, 1856). But how far you are at liberty to call up continents from “the vasty deep” as often as you want to convey a helix from the U.S. to Europe in Miocene or Pliocene periods is a question; for the Ocean is getting deeper of late, and Haughton says the mean depth is 11 miles! by his late paper on tides. I shall be surprised if this turns out true by soundings.
I thought your mind was expanding so much in regard to time that you would have been going ahead in regard to the possibility of mountain chains being created in a fraction of the period required to convert a swan into a goose or vice versâ. Nine feet did the Rimutaka chain of N. Zealand gain in height in Jan. 1855 and a great earthquake has occurred in N. Zealand every 7 years for half a century nearly. The Washingtonia (Californian conifer) lately exhibited was 4000 years old, so that one individual might see a chain of hills rise, and rise with it, much less a species—and those islands which J. Hooker describes as covered with N. Zealand plants 300? miles to the N.E.? of N.Z. may have been separated from the mainland 2 or 3 or 4 generations of Washingtonias ago.?
If the identity of the land shells of all the hundreds of British Isles be owing to their having been united since the Glacial Period and the discordance almost total of the shells of Porto Santo and Madeira be owing to their having been separated all the newer and possibly older pliocene periods, then it gives us a conception of Time which will aid you much in your conversion of species, if immensity of Time will do all you require for the glacial period is thus shown as we might have anticipated to be contemptible in duration or in distance from us, as compared to the older Pliocene, let alone the Miocene when our contemporary species were tho' in a minority, already beginning to flourish.
The littoral shells according to Macandrew imply that Madeira and the Canaries
were once joined to the main land of Europe or Africa but that those isles were
disjoined so long ago that most of the species came in since.
In short the marine shells tell the same story as the land shells. Why do the plants of
Sincerely yours | C. Lyell
- f1 1905.f1Sharpe 1856, which had been read on 5 December 1855. Daniel Sharpe had died on 31 May 1856.
- f2 1905.f2Sharpe 1856, pp. 118–23.
- f3 1905.f3The map given in the second volume of C. Lyell 1830–3, facing p. 304, entitled ‘Map shewing the extent of surface in Europe which has been covered by water since the commencement of the deposition of the older Tertiary strata (strata of the Paris and London basins &c &c.)’.
- f4 1905.f4An allusion to CD's theory that coral reefs originated by the gradual growth of corals as the floor of the ocean subsided (Coral reefs (1842)).
- f5 1905.f5Adam Sedgwick.
- f6 1905.f6The faluns of Touraine was identified by Lyell as a Miocene deposit, similar to but older than the coralline Crag of Suffolk (C. Lyell 1855, pp. 176–9). Nearly all the corals identified in the faluns were different from living forms, so that if the subsidence in the Pacific had taken place during the era of existing coral species, it must have occurred after the deposition of the faluns beds.
- f7 1905.f7An address given by James Dwight Dana as president of the American Association for the Advancement of Science in August 1855 (Dana 1855). Dana had suggested that during the Silurian period the United States was entirely covered by shallow seas.
- f8 1905.f8Haughton 1856, pp. 137–9, read on 24 April 1854. Samuel Haughton also presented his results in a short preliminary notice published earlier (Haughton 1853–4).
- f9 1905.f9Lyell refers to the first specimen of the giant sequoia tree, sometimes known as Washingtonia, to have been seen in England. It was brought to London in 1853 by William Lobb, who collected plants in California and Oregon from 1849 to 1857 for the Veitch nursery (R. Desmond 1977, p. 391). Now known as Sequoia gigantea, this specimen was first given the name Wellingtonia by John Lindley (EB).
- f10 1905.f10It is not clear whether Lyell is referring to Chatham Island, the flora of which Joseph Dalton Hooker described as the same as that of New Zealand in J. D. Hooker 1853–5, 1: vii, or to Raoul Island, in the Kermadec group, which also possesses a New Zealand flora but is some 600 miles from New Zealand. Hooker wrote a paper on the botany of Raoul Island in 1857 (J. D. Hooker 1857). CD's reply indicates that he thought Lyell referred to Raoul Island (see letter to Charles Lyell, 25 June ).
- f11 1905.f11McAndrew 1854. CD had corresponded with Robert McAndrew about the meaning of his results in 1855 (see Correspondence vol. 5, letter to Robert McAndrew, 6 October 1855).
- f12 1905.f12See letter to Charles Lyell, 25 June . Lyell evidently considered his questions to be important for he made a rough abstract of the main points in his scientific journal (see Wilson ed. 1970, pp. 104–5).