More Letters of Charles Darwin Volume I [36]
(these terms used topographically, not geologically) having been acquired by migration over continuous land (the glacial or alpine flora I except for the present--as ice-carriage might have played a great part in its introduction)--I considered it most probable, and maintained, that the introduction of that Irish flora was also effected by the same means. I held also that the character of this flora was more southern and more ancient than that of any of the others, and that its fragmentary and limited state was probably due to the plants composing it having (from their comparative hardiness--heaths, saxifrages, etc.) survived the destroying influence of the glacial epoch.
My geological argument now is as follows: half the Mediterranean islands, or more, are partly--in some cases (as Malta) wholly--composed of the upheaved bed of the Miocene sea; so is a great part of the south of France from Bordeaux to Montpellier; so is the west of Portugal; and we find the corresponding beds with the same fossils (Pecten latissimus, etc.) in the Azores. So general an upheaval seems to me to indicate the former existence of a great post-Miocene land [in] the region of what is usually called the Mediterranean flora. (Everywhere these Miocene islands, etc., bear a flora of true type.) If this land existed, it did not extend to America, for the fossils of the Miocene of America are representative and not identical. Where, then, was the edge or coast-line of it, Atlantic- wards? Look at the form and constancy of the great fucus-bank, and consider that it is a Sargassum bank, and that the Sargassum there is in an abnormal condition, and that the species of this genus of fuci are essentially ground-growers, and then see the probability of this bank having originated on a line of ancient coast.
Now, having thus argued independently, first on my flora and second on the geological evidences of land in the quarter required, I put the two together to bear up my Irish case.
I cannot admit the Sargassum case to be parallel with that of Confervae or Oscillatoria.
I think I have evidence from the fossils of the boulder formations in Ireland that if such Miocene land existed it must have been broken up or partially broken up at the epoch of the glacial or boulder period.
All objections thankfully received.
Ever most sincerely,
EDWARD FORBES.
LETTER 21. TO L. JENYNS (BLOMEFIELD). Down. [1846].
I am much obliged for your note and kind intended present of your volume. (21/1. No doubt the late Mr. Blomefield's "Observations in Natural History." See "Life and Letters," II., page 31.) I feel sure I shall like it, for all discussions and observations on what the world would call trifling points in Natural History always appear to me very interesting. In such foreign periodicals as I have seen, there are no such papers as White, or Waterton, or some few other naturalists in Loudon's and Charlesworth's Journal, would have written; and a great loss it has always appeared to me. I should have much liked to have met you in London, but I cannot leave home, as my wife is recovering from a rather sharp fever attack, and I am myself slaving to finish my S. American Geology (21/2. "Geological Observations in South America" (London), 1846.), of which, thanks to all Plutonic powers, two-thirds are through the press, and then I shall feel a comparatively free man. Have you any thoughts of Southampton? (21/3. The British Association met at Southampton in 1846.) I have some vague idea of going there, and should much enjoy meeting you.
LETTER 22. TO J.D. HOOKER. Shrewsbury [end of February 1846].
I came here on account of my father's health, which has been sadly failing of late, but to my great joy he has got surprisingly better...I had not heard of your botanical appointment (22/1. Sir Joseph was appointed Botanist to the Geological Survey in 1846.), and am very glad of it, more especially as it will make you travel and give you change of work and relaxation. Will you some time have to examine the Chalk and its junction
My geological argument now is as follows: half the Mediterranean islands, or more, are partly--in some cases (as Malta) wholly--composed of the upheaved bed of the Miocene sea; so is a great part of the south of France from Bordeaux to Montpellier; so is the west of Portugal; and we find the corresponding beds with the same fossils (Pecten latissimus, etc.) in the Azores. So general an upheaval seems to me to indicate the former existence of a great post-Miocene land [in] the region of what is usually called the Mediterranean flora. (Everywhere these Miocene islands, etc., bear a flora of true type.) If this land existed, it did not extend to America, for the fossils of the Miocene of America are representative and not identical. Where, then, was the edge or coast-line of it, Atlantic- wards? Look at the form and constancy of the great fucus-bank, and consider that it is a Sargassum bank, and that the Sargassum there is in an abnormal condition, and that the species of this genus of fuci are essentially ground-growers, and then see the probability of this bank having originated on a line of ancient coast.
Now, having thus argued independently, first on my flora and second on the geological evidences of land in the quarter required, I put the two together to bear up my Irish case.
I cannot admit the Sargassum case to be parallel with that of Confervae or Oscillatoria.
I think I have evidence from the fossils of the boulder formations in Ireland that if such Miocene land existed it must have been broken up or partially broken up at the epoch of the glacial or boulder period.
All objections thankfully received.
Ever most sincerely,
EDWARD FORBES.
LETTER 21. TO L. JENYNS (BLOMEFIELD). Down. [1846].
I am much obliged for your note and kind intended present of your volume. (21/1. No doubt the late Mr. Blomefield's "Observations in Natural History." See "Life and Letters," II., page 31.) I feel sure I shall like it, for all discussions and observations on what the world would call trifling points in Natural History always appear to me very interesting. In such foreign periodicals as I have seen, there are no such papers as White, or Waterton, or some few other naturalists in Loudon's and Charlesworth's Journal, would have written; and a great loss it has always appeared to me. I should have much liked to have met you in London, but I cannot leave home, as my wife is recovering from a rather sharp fever attack, and I am myself slaving to finish my S. American Geology (21/2. "Geological Observations in South America" (London), 1846.), of which, thanks to all Plutonic powers, two-thirds are through the press, and then I shall feel a comparatively free man. Have you any thoughts of Southampton? (21/3. The British Association met at Southampton in 1846.) I have some vague idea of going there, and should much enjoy meeting you.
LETTER 22. TO J.D. HOOKER. Shrewsbury [end of February 1846].
I came here on account of my father's health, which has been sadly failing of late, but to my great joy he has got surprisingly better...I had not heard of your botanical appointment (22/1. Sir Joseph was appointed Botanist to the Geological Survey in 1846.), and am very glad of it, more especially as it will make you travel and give you change of work and relaxation. Will you some time have to examine the Chalk and its junction