en at much
more considerable height. "), you will find a brief allusion, on
authority of Mr. D. Forbes, on the former much lower extension of
glaciers in the equatorial Cordillera. Pray also look at page 407 at
what I say on the nature of tropical vegetation (which I could now much
improve) during the Glacial period. (363/4. "During this, the coldest
period, the lowlands under the Equator must have been clothed with a
mingled tropical and temperate vegetation..." ("Origin," Edition VI.,
1882, page 338).)

I feel a strong conviction that soon every one will believe that the
whole world was cooler during the Glacial period. Remember Hooker's
wonderful case recently discovered of the identity of so many temperate
plants on the summit of Fernando Po, and on the mountains of Abyssinia.
(363/5. "Dr. Hooker has also lately shown that several of the plants
living in the upper parts of the lofty island of Fernando Po, and in
the neighbouring Cameroon Mountains, in the Gulf of Guinea, are closely
related to those on the mountains of Abyssinia, and likewise to those of
temperate Europe" (loc. cit., page 337).) I look at [it] as certain that
these plants crossed the whole of Africa from east to west during the
same period. I wish I had published a long chapter written in full, and
almost ready for the press, on this subject, which I wrote ten years
ago. It was impossible in the "Origin" to give a fair abstract.

My health is considerably improved, so that I am able to work nearly two
hours a day, and so make some little progress with my everlasting book
on domestic varieties. You will have heard of my sister Catherine's easy
death last Friday morning. (363/6. Catherine Darwin died in February
1866.) She suffered much, and we all look at her death as a blessing,
for there was much fear of prolonged and greater suffering. We are
uneasy about Susan, but she has hitherto borne it better than we could
have hoped. (363/7. Susan Darwin died in October 1866.)

Remember glacial action of Lebanon when you speak of no glacial action
in S. on Himalaya, and in S.E. Australia.

P.S.--I have been very glad to see Sir C. Bunbury's letter. (363/8. The
letter from Bunbury to Lyell, already quoted on this subject. Bunbury
writes: "There is nothing in the least NORTHERN, nothing that is not
characteristically Brazilian, in the flora of the Organ Mountains.") If
the genera which I name from Gardner (363/9. "Travels in the Interior
of Brazil," by G.