I gather that some one must have complained to Mr. Darwin of his saying that Isidore Geoffroy gave an account of Buffon’s “fluctuating conclusions” concerning evolution, when he was doing all he knew to maintain that Buffon’s conclusions did not fluctuate; for I see that in the edition of 1876 the word “fluctuating” has dropped out of the note in question, and we now learn that Isidore Geoffroy gives “a full account of Buffon’s conclusions,” without the “fluctuating.” But Buffon has not taken much by this, for his opinions are still left fluctuating greatly at different periods on the preceding page, and though he still was the first to treat evolution in a scientific spirit, he still does not enter upon the causes or means of the transformation of species. No one can understand Mr. Darwin who does not collate the different editions of the “Origin of Species” with some attention. When he has done this, he will know what Newton meant by saying he felt like a child playing with pebbles upon the seashore. One word more upon this note before I leave it. Mr. Darwin speaks of Isidore Geoffroy’s history of opinion as “excellent,” and his account of Buffon’s opinions as “full.” I wonder how well qualified he is to be a judge of these matters? If he knows much about the earlier writers, he is the more inexcusable for having said so little about them. If little, what is his opinion worth? To return to the “brief but imperfect sketch.” I do not think I can ever again be surprised at anything Mr. Darwin may say or do, but if I could, I should wonder how a writer who did not “enter upon the causes or means of the transformation of species,” and whose opinions “fluctuated greatly at different periods,” can be held to have treated evolution “in a scientific spirit.” Nevertheless, when I reflect upon the scientific reputation Mr. Darwin has attained, and the means by which he has won it, I suppose the scientific spirit must be much what he here implies. I see Mr. Darwin says of his own father, Dr. Robert Darwin of Shrewsbury, that he does not consider him to have had a scientific mind. Mr. Darwin cannot tell why he does not think his father’s mind to have been fitted for advancing science, “for he was fond of theorising, and was incomparably the best observer” Mr. Darwin ever knew. {33a} From the hint given in the “brief but imperfect sketch,” I fancy I can help Mr. Darwin to see why he does not think his father’s mind to have been a scientific one. It is possible that Dr. Robert Darwin’s opinions did not fluctuate sufficiently at different periods, and that Mr. Darwin considered him as having in some way entered upon the causes or means of the transformation of species. Certainly those who read Mr. Darwin’s own works attentively will find no lack of fluctuation in his case; and reflection will show them that a theory of evolution which relies mainly on the accumulation of accidental variations comes very close to not