these two things, and the rest is a mere matter of time and degree. That the immense differences between the camel and the pig should have come about in six thousand years is not believable; but in six hundred million years it is not incredible, more especially when we consider that by the assistance of geology a very perfect chain has been formed between the two. Let this instance suffice. Once grant the principles, once grant that competition is a great power in Nature, and that changes of circumstances and habits produce a tendency to variation in the offspring (no matter how slight such variation may be), and unless you can define the possible limit of such variation during an infinite series of generations, unless you can show that there is a limit, and that Darwin’s theory over-steps it, you have no right to reject his conclusions. As for the objections to the theory, Darwin has treated them with admirable candour, and our time is too brief to enter into them here. My recommendation to you is that you should read the book again. C. Thank you, but for my own part I confess to caring very little whether my millionth ancestor was a gorilla or no; and as Darwin’s book does not please me, I shall not trouble myself further about the matter. Barrel-Organs [From the _Press_, 17 January, 1863.] Dugald Stewart in his _Dissertation on the Progress of Metaphysics_ says: “On reflecting on the repeated reproduction of ancient paradoxes by modern authors one is almost tempted to suppose that human invention is limited, like a barrel-organ, to a specific number of tunes.” It would be a very amusing and instructive task for a man of reading and reflection to note down the instances he meets with of these old tunes coming up again and again in regular succession with hardly any change of note, and with all the old hitches and involuntary squeaks that the barrel-organ had played in days gone by. It is most amusing to see the old quotations repeated year after year and volume after volume, till at last some more careful enquirer turns to the passage referred to and finds that they have all been taken in and have followed the lead of the first daring inventor of the mis-statement. Hallam has had the courage, in the supplement to his _History of the Middle Ages_, p. 398, to acknowledge an error of this sort that he has been led into. But the particular instance of barrel-organism that is present to our minds just now is the Darwinian theory of the development of species by natural selection, of which we hear so much. This is nothing new, but a _réchauffée_ of the old story that his namesake, Dr. Darwin, served up in the end of the last century to Priestley and his admirers, and Lord Monboddo had cooked in the beginning of the same century. We have all heard of his theory that man was developed directly from the monkey, and that we all lost our tails by sitting too much upon that appendage.