My dear Lyell

It has been a great disappointm^t to me putting off your visit; as it has proved we might have had you.²

My sister’s state varies a little but she suffers greatly & there is no hope of recovery.³

We are very glad that you think you will be able to come here in Oct.⁴

Many thanks for the pamphlet which was returned this m^g.⁵ I was very glad to read it, though chiefly as a psychological curiosity. I quite follow you in thinking Agassiz glacier-mad. His evidence reduces itself to supposed moraines which w^d be difficult to trace in a forest-clad country; & with respect to boulders, these are not said to be angular & their source cannot be known in a country so imperfectly explored. When I was at Rio I was continually astonished at the depth (sometimes 100 feet) to which the granitic rocks were decomposed in situ;⁶ & this soft matter w^d easily give rise to great alluvial accumulations: I well remember finding it difficult to draw a line between the alluvial matter & the softened rock in situ.⁷ What a splendid imagination Agassiz has! & how energetic he is! What capital work he w^d have done if he had sucked in your Principles with his mother’s milk.⁸ It is wonderful that he sh^d have written such wild nonsense about the valley of the Amazon; yet not so wonderful when one remembers that he once maintained before the Brit. Assoc that the chalk was all deposited at once.⁹

With respect to the insects of Chili, I knew only from Bates that the species of Carabus shewed no special affinity to northern species; from the great difference of climate & vegetation, I sh^d not have expected that many insects w^d have shewn such affinity.¹⁰ It is more remarkable that the birds on the broad & lofty Cordillera of Tropical S. America shew no affinity with European species.¹¹ The little power of diffusion with birds has often struck me as a most singular fact, even more singular than the great power of diffusion with plants. Remember that we hope to see you in the autumn

yours affectionately | Charles Darwin

Sunday Morning

P.S. I have just received a letter from Asa Gray with the following passage, so that according to this, I am the chief cause of Agassiz’ absurd views.¹²

“Agassiz is back (I have not seen him) & he went at once down to Nat. Accad. of Sciences—from which I sedulously keep away—& I hear proved to them that the Glacial period covered the whole continent of America with unbroken ice, & closed with a significant gesture & the remark, “So here is the end of the Darwin Theory”. How do you like that?

I said last winter, that Agassiz was bent on covering the whole continent with ice & that the motive of the discovery he was sure to make was to make sure that there shd be no coming down of any terrestrial life from tertiary or post-tertiary period to ours. You cannot deny that he has done his work effectually, in a truly imperial way.”

P.S. There is a capital paper in the Sept. no^r of Annals & Mag, translated from Pictet & H. on fossil fish of Lebanon; but you will I daresay have received the original.— It is capital in relation to modification of species; I would not wish for more confirmatory facts, though there is no direct allusion to the modification of species.—¹³ Hooker, by the way, gave an admirable Lecture at Nottingham; I read it in M.S. or rather heard it.— I am glad it will be published, for it was capital.—¹⁴