From Charles Lyell 17 June 1856
53 Harley St., Lond.,
June 17, 1856.
My dear Darwin
I wonder you did not also mention D. Sharpe’s paper just published1 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.2 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.3 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.4 I could never feel sure whether he meant this tremendous catastrophe, all brought about by what Sedgwick5 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 specs of Atolls now growing6
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).7 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.8 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,9 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.?10
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.11 In short the marine shells tell the same story as the land shells. Why do the plants of Po So and Madeira agree so nearly? And why do the shells which are the same as European or African species remain quite unaltered like the Crag species which returned unchanged to the British seas after being expelled from them by Glacial cold, when 2 millions? of years had elapsed, and after such migration to milder seas. Be so good as to explain all this in your next letter.12
Sincerely yours | C. Lyell
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?
Please cite as
Darwin Correspondence Project, “Letter no. 1905,” accessed on 25 March 2017, http://www.darwinproject.ac.uk/DCP-LETT-1905