ON THE ORIGIN OF SPECIES.
OR THE PRESERVATION OF FAVOURED RACES IN THE STRUGGLE FOR LIFE.
By Charles Darwin, M.A.,
Fellow Of The Royal, Geological, Linnaean, Etc., Societies;
Author Of 'Journal Of Researches During H.M.S. Beagle's Voyage Round The World.'
From the First Edition
"But with regard to the material world, we can at least go so far as this--we can perceive that events are brought about not by insulated interpositions of Divine power, exerted in each particular case, but by the establishment of general laws."
W. Whewell: Bridgewater Treatise.
"To conclude, therefore, let no man out of a weak conceit of sobriety, or an ill-applied moderation, think or maintain, that a man can search too far or be too well studied in the book of God's word, or in the book of God's works; divinity or philosophy; but rather let men endeavour an endless progress or proficience in both."
Bacon: Advancement of Learning.
CHAPTER 1. VARIATION UNDER DOMESTICATION.
CHAPTER 2. VARIATION UNDER NATURE.
CHAPTER 3. STRUGGLE FOR EXISTENCE.
CHAPTER 4. NATURAL SELECTION.
CHAPTER 5. LAWS OF VARIATION.
CHAPTER 6. DIFFICULTIES ON THEORY.
CHAPTER 7. INSTINCT.
CHAPTER 8. HYBRIDISM.
CHAPTER 9. ON THE IMPERFECTION OF THE GEOLOGICAL RECORD.
CHAPTER 10. ON THE GEOLOGICAL SUCCESSION OF ORGANIC BEINGS.
CHAPTER 11. GEOGRAPHICAL DISTRIBUTION.
CHAPTER 12. GEOGRAPHICAL DISTRIBUTION幼ontinued.
CHAPTER 13. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY:
CHAPTER 14. 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.
ON THE ORIGIN OF SPECIES.
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.
I much regret that want of space prevents my having the satisfaction of acknowledging the generous assistance which I have received from very many naturalists, some of them personally unknown to me. I cannot, however, let this opportunity pass without expressing my deep obligations to Dr. Hooker, who for the last fifteen years has aided me in every possible way by his large stores of knowledge and his excellent judgment.
In considering the Origin of Species, it is quite conceivable that a naturalist, reflecting on the mutual affinities of organic beings, on their embryological relations, their geographical distribution, geological succession, and other such facts, might come to the conclusion that each species had not been independently created, but had descended, like varieties, from other species. Nevertheless, such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which most justly excites our admiration. Naturalists continually refer to external conditions, such as climate, food, etc., as the only possible cause of variation. In one very limited sense, as we shall hereafter see, this may be true; but it is preposterous to attribute to mere external conditions, the structure, for instance, of the woodpecker, with its feet, tail, beak, and tongue, so admirably adapted to catch insects under the bark of trees. In the case of the misseltoe, which draws its nourishment from certain trees, which has seeds that must be transported by certain birds, and which has flowers with separate sexes absolutely requiring the agency of certain insects to bring pollen from one flower to the other, it is equally preposterous to account for the structure of this parasite, with its relations to several distinct organic beings, by the effects of external conditions, or of habit, or of the volition of the plant itself.