in closely consecutive formations and within the same country; extinct marsupials having preceded living marsupials in Australia, and armadillo-like animals having preceded and generated armadilloes in South America,--and many other phenomena, such as the gradual extinction of old forms and their gradual replacement by new forms better fitted for their new conditions in the struggle for life. When the advocate of Heterogeny can thus connect large classes of facts, and not until then, he will have respectful and patient listeners.") (the first and last time I shall take such a step) to say, under the cloak of attacking Heterogeny, a word in my own defence. My letter is to appear next week, so the Editor says; and I mean to quote Lyell's sentence (See the next letter.) in his second edition, on the principle if one puffs oneself, one had better puff handsomely... CHARLES DARWIN TO C. LYELL. Down, April 18 [1863]. My dear Lyell, I was really quite sorry that you had sent me a second copy (The second edition of the 'Antiquity of Man' was published a few months after the first had appeared.) of your valuable book. But after a few hours my sorrow vanished for this reason: I have written a letter to the "Athenaeum", in order, under the cloak of attacking the monstrous article on Heterogeny, to say a word for myself in answer to Carpenter, and now I have inserted a few sentences in allusion to your analogous objection (Lyell objected that the mammalia (e.g. bats and seals) which alone have been able to reach oceanic islands ought to have become modified into various terrestrial forms fitted to fill various places in their new home. My father pointed out in the "Athenaeum" that Sir Charles has in some measure answered his own objection, and went on to quote the "amended sentence" ('Antiquity of Man,' 2nd Edition page 469) as showing how far Lyell agreed with the general doctrines of the "Origin of Species': "Yet we ought by no means to undervalue the importance of the step which will have been made, should it hereafter become the generally received opinion of men of science (as I fully expect it will) that the past changes of the organic world have been brought about by the subordinate agency of such causes as Variation and Natural Selection." In the first edition the words (as I fully expect it will," do not occur.) about bats on islands, and then with infinite slyness have quoted your amended sentence, with your parenthesis ("as I fully believe") (My father here quotes Lyell incorrectly; see the previous foot-note.); I do not think you can be annoyed at my doing this, and you see, that I am determined as far as I can, that the public shall see how far you go. This is the first time I have ever said a word for myself in any journal, and it shall, I think, be the last. My letter is short, and no great things. I was extremely concerned to see Falconer's disrespectful and virulent letter. I like extremely your