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).