rity of subject-matter, I think, upon reading again, after an
interval of ten years, his admirable presentation of the evidence it may
also in part be due to unconscious memory. This applies particularly to
the headings of the chapters, which I find to be almost identical with
those previously used by Mr. Spencer.

G. J. R.

CONTENTS.

PAGE

INTRODUCTION 1

I.
THE ARGUMENT FROM CLASSIFICATION 17

II.
THE ARGUMENT FROM MORPHOLOGY OR STRUCTURE 26

III.
THE ARGUMENT FROM GEOLOGY 46

IV.
THE ARGUMENT FROM GEOGRAPHICAL DISTRIBUTION 48

V.
THE ARGUMENT FROM EMBRYOLOGY 63

VI.
ARGUMENTS DRAWN FROM CERTAIN GENERAL CONSIDERATIONS 70

THE SCIENTIFIC EVIDENCES

OF

ORGANIC EVOLUTION.

Although it is generally recognised that the _Origin of Species_ has
produced an effect both on the science and the philosophy of our age
which is without a parallel in the history of thought, admirers of Mr.
Darwin's genius are frequently surprised at the ignorance of his work
which is displayed by many persons who can scarcely be said to belong to
the uncultured classes. The reason of this ignorance is no doubt partly
due to the busy life which many of our bread-winners are constrained to
live; but it is also, I think, partly due to mere indolence. There are
thousands of educated persons who, on coming home from their daily work,
prefer reading literature of a less scientific character than that which
is supplied by Mr. Darwin's works; and therefore it is that such persons
feel these works to belong to a category of books which is to them a
very large one--the books, namely, which never are, but always to be,
read. Under these circumstances I have thought it desirable to supply a
short digest of the _Origin of Species_, which any man, of however busy
a life, or of however indolent a disposition, may find both time and
energy to follow.

With the general aim of the present abstract being thus understood, I
shall start at the beginning of my subject by very briefly describing
the theory of natural selection. It is a matter of observable fact that
all plants and animals are perpetually engaged in what Mr. Darwin calls
a "struggle for existence." That is to say, in every generation of every
species a great many more individuals are born than can possibly
survive;