ans. Geolog.
Soc. Glasgow," III.). At page 336 Mr. Huxley deals with Lord Kelvin's
"third line of argument, based on the temperature of the interior of the
earth." This was no doubt the point most disturbing to Mr. Darwin, since
it led Lord Kelvin to ask (as quoted by Huxley), "Are modern geologists
prepared to say that all life was killed off the earth 50,000, 100,000,
or 200,000 years ago?" Mr. Huxley, after criticising Lord Kelvin's data
and conclusion, gives his conviction that the case against Geology has
broken down. With regard to evolution, Huxley (page 328) ingeniously
points out a case of circular reasoning. "But it may be said that it
is biology, and not geology, which asks for so much time--that the
succession of life demands vast intervals; but this appears to me to
be reasoning in a circle. Biology takes her time from geology. The only
reason we have for believing in the slow rate of the change in living
forms is the fact that they persist through a series of deposits which,
geology informs us, have taken a long while to make. If the geological
clock is wrong, all the naturalist will have to do is to modify his
notions of the rapidity of change accordingly.")

LETTER 384. TO J.D. HOOKER. February 3rd [1868].

I am now reading Miquel on "Flora of Japan" (384/1. Miquel, "Flore du
Japon": "Archives Neerlandaises" ii., 1867.), and like it: it is rather
a relief to me (though, of course, not new to you) to find so very
much in common with Asia. I wonder if A. Murray's (384/2. "Geographical
Distribution of Mammals," by Andrew Murray, 1866. See Chapter V., page
47. See Letter 379.) notion can be correct, that a [profound] arm of
the sea penetrated the west coast of N. America, and prevented the
Asiatico-Japan element colonising that side of the continent so much
as the eastern side; or will climate suffice? I shall to the day of my
death keep up my full interest in Geographical Distribution, but I doubt
whether I shall ever have strength to come in any fuller detail than in
the "Origin" to this grand subject. In fact, I do not suppose any man
could master so comprehensive a subject as it now has become, if all
kingdoms of nature are included. I have read Murray's book, and am
disappointed--though, as you said, here and there clever thoughts occur.
How strange it is, that his view not affording the least explanation of
the innumerable adaptations everywhere to be seen apparently does not
in the least trouble hi