rtance of the
geological evidence in any presentation of his theory a striking proof
will be found in a passage of the touching letter to his wife, enjoining
the publication of his sketch of 1844. "In case of my sudden death,"
he wrote, "... the editor must be a geologist as well as a naturalist."
("L.L." II. pages 16, 17.)

In spite of the numerous and valuable palaeontological discoveries made
since the publication of "The Origin of Species", the importance of the
first of these two geological chapters is as great as ever. It still
remains true that "Those who believe that the geological record is in
any degree perfect, will at once reject the theory"--as indeed they must
reject any theory of evolution. The striking passage with which Darwin
concludes this chapter--in which he compares the record of the rocks
to the much mutilated volumes of a human history--remains as apt an
illustration as it did when first written.

And the second geological chapter, on the Succession of Organic
Beings--though it has been strengthened in a thousand ways, by the
discoveries concerning the pedigrees of the horse, the elephant and
many other aberrant types, though new light has been thrown even on the
origin of great groups like the mammals, and the gymnosperms, though
not a few fresh links have been discovered in the chains of evidence,
concerning the order of appearance of new forms of life--we would
not wish to have re-written. Only the same line of argument could be
adopted, though with innumerable fresh illustrations. Those who reject
the reasonings of this chapter, neither would they be persuaded if a
long and complete succession of "ancestral forms" could rise from the
dead and pass in procession before them.

Among the geological discussions, which so frequently occupied Darwin's
attention during the later years of his life, there was one concerning
which his attitude seemed somewhat remarkable--I allude to his views
on "the permanence of Continents and Ocean-basins." In a letter to Mr
Mellard Reade, written at the end of 1880, he wrote: "On the whole, I
lean to the side that the continents have since Cambrian times occupied
approximately their present positions. But, as I have said, the question
seems a difficult one, and the more it is discussed the better." ("M.L."
II. page 147.) Since this was written, the important contribution to the
subject by the late Dr W.T. Blanford (himself, like Darwin, a naturalist
and geologis