entering upon the causes or means of the transformation of species. {33b} I have shown, however, in “Evolution, Old and New,” that the assertion that Buffon does not enter on the causes or means of the transformation of species is absolutely without foundation, and that, on the contrary, he is continually dealing with this very matter, and devotes to it one of his longest and most important chapters, {33c} but I admit that he is less satisfactory on this head than either Dr. Erasmus Darwin or Lamarck. As a matter of fact, Buffon is much more of a Neo-Darwinian than either Dr. Erasmus Darwin or Lamarck, for with him the variations are sometimes fortuitous. In the case of the dog, he speaks of them as making their appearance “_by some chance_ common enough with Nature,” {33d} and being perpetuated by man’s selection. This is exactly the “if any slight favourable variation _happen_ to arise” of Mr. Charles Darwin. Buffon also speaks of the variations among pigeons arising “_par hasard_.” But these expressions are only ships; his main cause of variation is the direct action of changed conditions of existence, while with Dr. Erasmus Darwin and Lamarck the action of the conditions of existence is indirect, the direct action being that of the animals or plants themselves, in consequence of changed sense of need under changed conditions. I should say that the sketch so often referred to is at first sight now no longer imperfect in Mr. Darwin’s opinion. It was “brief but imperfect” in 1861 and in 1866, but in 1876 I see that it is brief only. Of course, discovering that it was no longer imperfect, I expected to find it briefer. What, then, was my surprise at finding that it had become rather longer? I have found no perfectly satisfactory explanation of this inconsistency, but, on the whole, incline to think that the “greatest of living men” felt himself unequal to prolonging his struggle with the word “but,” and resolved to lay that conjunction at all hazards, even though the doing so might cost him the balance of his adjectives; for I think he must know that his sketch is still imperfect. From Isidore Geoffroy I turned to Buffon himself, and had not long to wait before I felt that I was now brought into communication with the master-mind of all those who have up to the present time busied themselves with evolution. For a brief and imperfect sketch of him, I must refer my readers to “Evolution, Old and New.”