Your letter received this morning interested me more than even most of your letters, and that is saying a good deal. I must scribble a little on several points. About Lyell and species--you put the whole case, I do believe, when you say that he is "half-hearted and whole-headed." (168/1. Darwin's disappointment with the cautious point of view taken up by Lyell in the "Antiquity of Man" is illustrated in the "Life and Letters," III., pages 11, 13. See also Letter 164, page 239.) I wrote to A. Gray that, when I saw such men as Lyell and he refuse to judge, it put me in despair, and that I sometimes thought I should prefer that Lyell had judged against modification of species rather than profess inability to decide; and I left him to apply this to himself. I am heartily rejoiced to hear that you intend to try to bring L. and F. (168/2. Falconer claimed that Lyell had not "done justice to the part he took in resuscitating the cave question." See "Life and Letters," III., page 14.) together again; but had you not better wait till they are a little cooled? You will do Science a real good service. Falconer never forgave Lyell for taking the Purbeck bones from him and handing them over to Owen. With respect to island floras, if I understand rightly, we differ almost solely how plants first got there. I suppose that at long intervals, from as far back as later Tertiary periods to the present time, plants occasionally arrived (in some cases, perhaps, aided by different currents from existing currents and by former islands), and that these old arrivals have survived little modified on the islands, but have become greatly modified or become extinct on the continent. If I understand, you believe that all islands were formerly united to continents, and then received all their plants and none since; and that on the islands they have undergone less extinction and modification than on the continent. The number of animal forms on islands, very closely allied to those on continents, with a few extremely distinct and anomalous, does not seem to me well to harmonise with your supposed view of all having formerly arrived or rather having been left together on the island. LETTER 169. TO ASA GRAY. Down, May 31st [1863?]. I was very glad to receive your review (169/1. The review on De Candolle's work on the Oaks (A. Gray's "Scientific Papers," I., page 130).) of De Candolle a week ago. It seems to me excellent, and you speak out, I think, more plainly in favour of derivation of species than hitherto, though doubtfully about Natural Selection. Grant the first, I am easy about the second. Do you not consider such cases as all the orchids next thing to a demonstration against Heer's view of species arising suddenly by monstrosities?--it is impossible to imagine so many co-adaptations being formed all by a chance blow. Of course creationists would cut the enigma. LETTER 170. TO T.H. HUXLEY. June 27th [1863?]