To Ernst Krause   28 November 1880

My dear Sir

I must thank you for your most interesting letter.¹ It is very bad news about Kosmos: I shall regret much its cessation, for I found in every number something which interested me greatly. Anyhow you must have the satisfaction of feeling that you have been an excellent editor, & have aided Science in every way.—²

It is, also, grievous news about Fritz Müller,—that is if he has lost his instruments & books. I have long looked on him as the best observer in the world. I have written to his brother, Hermann, to learn whether he has suffered much loss, & whether for the sake of Science, he would allow me to aid him in purchasing new microscopes &c &c.—³

I do not know when I have been so much astonished, as by your account of the Crustacean which repairs its legs by those of an ancestral form. If I understand the case, it must be a kind of localised reversion! This seems to me to support, the hypothesis of Pangenesis, which has hardly any friends in this world. I can conceive a small collection of molecules (ie one of my imaginary gemmules) remaining dormant in an organism for almost any length of time; but I think it will be difficult for Häckel to make others believe that certain molecules, of which the body is built, have gone on vibrating for countless generations in a peculiar manner, so as to form when occasion offers an ancestral limb. If I remember rightly the reproduced tail of Lacerta differs from the normal tail. I have given one case in some slight degree analogous, namely that of a hen which when barren assumed the male plumage of an ancestral breed, & not of her own breed.—⁴ But I did not intend to trouble you with my notions or about pangenesis.—

My dear Sir | Yours sincerely | Chas. Darwin