the earth and its
inhabitants." But he proceeds: "The very same evidence which has been
adduced to prove the GENERAL stability and permanence of our continental
areas also goes to prove that they have been subjected to wonderful
and repeated changes in DETAIL." (Loc. cit. page 101.) Darwin of course
would have admitted this, for with a happy expression he insisted
to Lyell (1856) that "the skeletons, at least, of our continents are
ancient." ("More Letters", II. page 135.) It is impossible not to
admire the courage and tenacity with which he carried on the conflict
single-handed. But he failed to convince Lyell. For we still find
him maintaining in the last edition of the "Principles": "Continents
therefore, although permanent for whole geological epochs, shift their
positions entirely in the course of ages." (Lyell's "Principles of
Geology" (11th edition), London, 1872, I. page 258.)

Evidence, however, steadily accumulates in Darwin's support. His
position still remains inexpugnable that it is not permissible to invoke
geographical change to explain difficulties in distribution without
valid geological and physical support. Writing to Mellard Reade, who in
1878 had said, "While believing that the ocean-depths are of enormous
age, it is impossible to reject other evidences that they have once
been land," he pointed out "the statement from the 'Challenger' that all
sediment is deposited within one or two hundred miles from the shores."
("More Letters", II. page 146.) The following year Sir Archibald Geikie
("Geographical Evolution", "Proc. R. Geogr. Soc." 1879, page 427.)
informed the Royal Geographical Society that "No part of the results
obtained by the 'Challenger' expedition has a profounder interest for
geologists and geographers than the proof which they furnish that the
floor of the ocean basins has no real analogy among the sedimentary
formations which form most of the framework of the land."

Nor has Darwin's earlier argument ever been upset. "The fact which
I pointed out many years ago, that all oceanic islands are volcanic
(except St Paul's, and now that is viewed by some as the nucleus of an
ancient volcano), seem to me a strong argument that no continent ever
occupied the great oceans." ("More Letters", II. page 146.)

Dr Guppy, who devoted several years to geological and botanical
investigations in the Pacific, found himself forced to similar
conclusions. "It may be at once observed," he says, "that my