But just in proportion as this process of extermination has acted on an enormous scale, so must the number of intermediate varieties, which have formerly existed, be truly enormous. Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain; and this, perhaps, is the most obvious and serious objection which can be urged against the theory. The explanation lies, as I believe, in the extreme imperfection of the geological record.
Charles DarwinI am quite conscious that my speculations run beyond the bounds of true science....It is a mere rag of an hypothesis with as many flaw[s] & holes as sound parts.
Charles DarwinIf I had not been so great an invalid, I should not have done so much as I have accomplished.
Charles DarwinI think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct. The forms which stand in closest competition with those undergoing modification and improvement will naturally suffer most.
Charles DarwinWho when examining in the cabinet of the entomologist the gay and exotic butterflies, and singular cicadas, will associate with these lifeless objects, the ceaseless harsh music of the latter, and the lazy flight of the former - the sure accompaniments of the still, glowing noonday of the tropics.
Charles Darwin