el, 1840.); as for his inferences and reasoning on
the valley of the Amazon that is quite another question, nor can he have
seen all the regions to which Mrs. A. alludes. (363/2. A letter from
Mrs. Agassiz to Lady Lyell, which had been forwarded to Mr. Darwin. The
same letter was sent also to Sir Charles Bunbury, who, in writing to
Lyell on February 3rd, 1866, criticises some of the statements. He
speaks of Agassiz's observations on glacial phenomena in Brazil as "very
astonishing indeed; so astonishing that I have very great difficulty in
believing them. They shake my faith in the glacial system altogether; or
perhaps they ought rather to shake the faith in Agassiz...If Brazil
was ever covered with glaciers, I can see no reason why the whole earth
should not have been so. Perhaps the whole terrestrial globe was once
'one entire and perfect icicle.'" (From the privately printed "Life" of
Sir Charles Bunbury, edited by Lady Bunbury, Volume ii., page 334).) Her
letter is not very clear to me, and I do not understand what she means
by "to a height of more than three thousand feet." There are no erratic
boulders (to which I particularly attended ) in the low country round
Rio. It is possible or even probable that this area may have subsided,
for I could detect no evidence of elevation, or any Tertiary formations
or volcanic action. The Organ Mountains are from six to seven thousand
feet in height; and I am only a little surprised at their bearing the
marks of glacial action. For some temperate genera of plants, viz.,
Vaccinium, Andromeda, Gaultheria, Hypericum, Drosera, Habenaria, inhabit
these mountains, and I look at this almost as good evidence of a cold
period, as glacial action. That there are not more temperate plants can
be accounted for by the isolated position of these mountains. There are
no erratic boulders on the Pacific coast north of Chiloe, and but few
glaciers in the Cordillera, but it by no means follows, I think, that
there may not have been formerly gigantic glaciers on the eastern and
more humid side.

In the third edition of "Origin," page 403 (363/3. "Origin," Edition
VI., page 335, 1882. "Mr. D. Forbes informs me that he found in various
parts of the Cordillera, from lat. 13 deg W. to 30 deg S., at about the
height of twelve thousand feet, deeply furrowed rocks...and likewise
great masses of detritus, including grooved pebbles. Along this whole
space of the Cordillera true glaciers do not now exist, ev