Two years later the original publishers of this book and of that on South
America proposed to re-issue them. Darwin at first hesitated, for he seemed
to think there could be little of abiding interest in them; he consulted me
upon the subject in one of the conversations which I used to have with him
at that time, and I strongly urged upon him the reprint of the works. I was
much gratified when he gave way upon the point, and consented to their
appearing just as originally issued. In his preface he says, "Owing to the
great progress which Geology has made in recent times, my views on some few
points may be somewhat antiquated, but I have thought it best to leave them
as they originally appeared."

It may be interesting to indicate, as briefly as possible, the chief
geological problem upon which the publication of Darwin's "Volcanic
Islands" threw new and important light. The merit of the work consisted in
supplying interesting observations, which in some cases have proved of
crucial value in exploding prevalent fallacies; in calling attention to
phenomena and considerations that had been quite overlooked by geologists,
but have since exercised an important influence in moulding geological
speculation; and lastly in showing the importance which attaches to small
and seemingly insignificant causes, some of which afford a key to the
explanation of very curious geological problems.

Visiting as he did the districts in which Von Buch and others had found
what they thought to be evidence of the truth of "Elevation-craters,"
Darwin was able to show that the facts were capable of a totally different
interpretation. The views originally put forward by the old German
geologist and traveller, and almost universally accepted by his countrymen,
had met with much support from Elie de Beaumont and Dufrenoy, the leaders
of geological thought in France. They were, however, stoutly opposed by