withstanding our many differences of opinion, I feel to be one
of the greatest honours of my life."--WALLACE to Darwin.

"I think the way he [Wallace] carries on controversy is perfectly
beautiful, and in future histories of science the Wallace-Darwin
episode will form one of the few bright points among rival
claimants."--ERASMUS DARWIN to his niece, Henrietta Darwin, 1871.

The first eight letters from Darwin to Wallace were found amongst the
latter's papers, carefully preserved in an envelope on the outside of
which he had written the words reproduced on the next page. Neither
Wallace's part of this correspondence, nor the original MS. of his essay
"On the Tendency of Varieties to Depart Indefinitely from the Original
Type," which he sent to Darwin from Ternate, has been discovered. But
these eight letters from Darwin explain themselves and reveal the inner
story of the independent discovery of the theory of Natural Selection.

With respect to the letters which follow the first eight, both sides of
the correspondence, with few exceptions, have been brought together.
Some of the letters have already appeared in "The Life and Letters of
Charles Darwin" and "More Letters," others in "My Life," by A.R.
Wallace, whilst many have not before been published.

Some of these letters, in themselves, have little more than ephemeral
interest, and parts of other letters could have been eliminated, from
the point of view of lightening this volume and of economising the
reader's attention. But I decided, with the fullest approval of the
Wallace and Darwin families, that the letters of these illustrious
correspondents should be here presented as a whole, without mutilation.

[Illustration: FACSIMILE OF INSCRIPTION BY WALLACE ON THE ENVELOPE IN
WHICH HE KEPT THE FIRST EIGHT LETTERS HE RECEIVED FROM DARWIN.]

Many of the notes of explanation to the Wallace letters have been
gathered from his own writings, and are mainly in his own words, and in
such cases the reader has the advantage of perusing letters annotated by
their author, while most of the notes to the Darwin letters are by Sir
F. Darwin.

* * * * *

LETTER I

C. DARWIN to A.R. WALLACE

_Down, Bromley, Kent, May 1, 1857._

My dear Sir,--I am much obliged for your letter of Oct. 10th from
Celebes, received a few days ago: in a laborious undertaking, sympathy
is a valuable and real encouragement. By your letter, an