one of our greatest philosophers. On my return home, it occurred to
me, in 1837, that something might perhaps be made out on this question
by patiently accumulating and reflecting on all sorts of facts which
could possibly have any bearing on it. After five years' work I
allowed myself to speculate on the subject, and drew up some short
notes; these I enlarged in 1844 into a sketch of the conclusions,
which then seemed to me probable: from that period to the present day
I have steadily pursued the same object. I hope that I may be excused
for entering on these personal details, as I give them to show that I
have not been hasty in coming to a decision.

My work is now nearly finished; but as it will take me two or three
more years to complete it, and as my health is far from strong, I have
been urged to publish this Abstract. I have more especially been
induced to do this, as Mr. Wallace, who is now studying the natural
history of the Malay archipelago, has arrived at almost exactly the
same general conclusions that I have on the origin of species. Last
year he sent to me a memoir on this subject, with a request that I
would forward it to Sir Charles Lyell, who sent it to the Linnean
Society, and it is published in the third volume of the Journal of
that Society. Sir C. Lyell and Dr. Hooker, who both knew of my
work--the latter having read my sketch of 1844--honoured me by
thinking it advisable to publish, with Mr. Wallace's excellent memoir,
some brief extracts from my manuscripts.

This Abstract, which I now publish, must necessarily be imperfect. I
cannot here give references and authorities for my several statements;
and I must trust to the reader reposing some confidence in my
accuracy. No doubt errors will have crept in, though I hope I have
always been cautious in trusting to good authorities alone. I can here