essay in the "Nature Series " with such

additions and alterations as appear to me, on second thoughts, to be desirable. The only object of the essay is that which is expressed in the opening paragraph.

LONDON,

June 1, 1882.

SINCE this little Essay was published, it has been suggested to me that, in its mode of presenting the arguments in favour of Evolution, there is a similarity to that which has been adopted by Mr. Herbert Spencer in the third part of his Principles of Biology. I should therefore like to state, that while such similarity is no doubt in part due to the similarity 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.

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

B

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 onethe 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