e former only I
urged at Cambridge; the latter I have not yet publicly maintained.

My Cambridge argument (20/2. "On the Distribution of Endemic Plants,"
by E. Forbes, "Brit. Assoc. Rep." 1845 (Cambridge), page 67.) was this:
That no known currents, whether of water or air, or ordinary means of
transport (20/3. Darwin's note on transportation (found with Forbes'
letter): "Forbes' arguments, from several Spanish plants in Ireland not
being transported, not sound, because sea-currents and air ditto and
migration of birds in SAME LINES. I have thought not-transportation
the greatest difficulty. Now we see how many seeds every plant and tree
requires to be regularly propagated in its own country, for we cannot
think the great number of seeds superfluous, and therefore how small is
the chance of here and there a solitary seedling being preserved in a
well-stocked country."), would account for the little group of Asturian
plants--few as to species, but playing a conspicuous part in the
vegetation--giving a peculiar botanical character to the south of
Ireland; that, as I had produced evidence of the other floras of our
islands, i.e. the Germanic, the Cretaceous, and the Devonian (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 fl