--EMBRYOLOGY, laws of, explained by variations not supervening at
an early age, and being inherited at a corresponding age--RUDIMENTARY
ORGANS; their origin explained--Summary

411-458

CHAPTER XIV.

RECAPITULATION AND CONCLUSION.

Recapitulation of the difficulties on the theory of Natural
Selection--Recapitulation of the general and special circumstances in its
favour--Causes of the general belief in the immutability of species--How
far the theory of natural selection may be extended--Effects of its
adoption on the study of Natural history--Concluding remarks

459-490

* * * * *

{1}

ON THE ORIGIN OF SPECIES.

* * * * *

INTRODUCTION.

When on board H.M.S. 'Beagle,' as naturalist, I was much struck with
certain facts in the distribution of the inhabitants of South America, and
in the geological relations of the present to the past inhabitants of that
continent. These facts seemed to me to throw some light on the origin of
species--that mystery of mysteries, as it has been called by 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 {2} 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 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--ho