material we have been able to compile an almost complete record of Mr.
Darwin's work in a series of letters now published for the first time. We
have, however, in a few instances, repeated paragraphs, or in one or two
cases whole letters, from the "Life and Letters," where such repetition
seemed necessary for the sake of clearness or continuity.

Our two volumes contain practically all the matter that it now seems
desirable to publish. But at some future time others may find interesting
data in what remains unprinted; this is certainly true of a short series of
letters dealing with the Cirripedes, which are omitted solely for want of
space. (Preface/1. Those addressed to the late Albany Hancock have
already appeared in the "Transactions of the Tyneside Nat. Field Club,"
VIII., page 250.)

We are fortunate in being permitted, by Sir Joseph Hooker and by Mr.
Wallace, to publish certain letters from them to Mr. Darwin. We have also
been able to give a few letters from Sir Charles Lyell, Hugh Falconer,
Edward Forbes, Dr. Asa Gray, Professor Hyatt, Fritz Muller, Mr. Francis
Galton, and Sir T. Lauder Brunton. To the two last named, also to Mrs.
Lyell (the biographer of Sir Charles), Mrs. Asa Gray and Mrs. Hyatt, we
desire to express our grateful acknowledgments.

The present volumes have been prepared, so as to give as full an idea as
possible of the course of Mr. Darwin's work. The volumes therefore
necessarily contain many letters of a highly technical character, but none,
we hope, which are not essentially interesting. With a view to saving
space, we have confined ourselves to elucidating the letters by full
annotations, and have for the same reason--though with some regret--omitted
in most cases the beginnings and endings of the letters. For the main
facts of Mr. Darwin's life, we refer our readers to the abstract of his