The Descent of Man and Selection in Relation to Sex HTML version

Preface To The Second Edition
During the successive reprints of the first edition of this work, published in 1871, I was
able to introduce several important corrections; and now that more time has elapsed, I
have endeavoured to profit by the fiery ordeal through which the book has passed, and
have taken advantage of all the criticisms which seem to me sound. I am also greatly
indebted to a large number of correspondents for the communication of a surprising
number of new facts and remarks. These have been so numerous, that I have been able to
use only the more important ones; and of these, as well as of the more important
corrections, I will append a list. Some new illustrations have been introduced, and four of
the old drawings have been replaced by better ones, done from life by Mr. T.W. Wood. I
must especially call attention to some observations which I owe to the kindness of Prof.
Huxley (given as a supplement at the end of Part I.), on the nature of the differences
between the brains of man and the higher apes. I have been particularly glad to give these
observations, because during the last few years several memoirs on the subject have
appeared on the Continent, and their importance has been, in some cases, greatly
exaggerated by popular writers.
I may take this opportunity of remarking that my critics frequently assume that I attribute
all changes of corporeal structure and mental power exclusively to the natural selection of
such variations as are often called spontaneous; whereas, even in the first edition of the
'Origin of Species,' I distinctly stated that great weight must be attributed to the inherited
effects of use and disuse, with respect both to the body and mind. I also attributed some
amount of modification to the direct and prolonged action of changed conditions of life.
Some allowance, too, must be made for occasional reversions of structure; nor must we
forget what I have called "correlated" growth, meaning, thereby, that various parts of the
organisation are in some unknown manner so connected, that when one part varies, so do
others; and if variations in the one are accumulated by selection, other parts will be
modified. Again, it has been said by several critics, that when I found that many details of
structure in man could not be explained through natural selection, I invented sexual
selection; I gave, however, a tolerably clear sketch of this principle in the first edition of
the 'Origin of Species,' and I there stated that it was applicable to man. This subject of
sexual selection has been treated at full length in the present work, simply because an
opportunity was here first afforded me. I have been struck with the likeness of many of
the half-favourable criticisms on sexual selection, with those which appeared at first on
natural selection; such as, that it would explain some few details, but certainly was not
applicable to the extent to which I have employed it. My conviction of the power of
sexual selection remains unshaken; but it is probable, or almost certain, that several of my
conclusions will hereafter be found erroneous; this can hardly fail to be the case in the
first treatment of a subject. When naturalists have become familiar with the idea of sexual
selection, it will, as I believe, be much more largely accepted; and it has already been
fully and favourably received by several capable judges.
September, 1874.
First Edition February 24, 1871.
Second Edition September, 1874.