As you have stated in your preface that my book, “Evolution, Old and New,” appeared subsequently to Dr. Krause’s article, and as no intimation is given that the article has been altered and added to since its original appearance, while the accuracy of the translation as though from the February number of _Kosmos_ is, as you expressly say, guaranteed by Mr. Dallas’s “scientific reputation together with his knowledge of German,” your readers will naturally suppose that all they read in the translation appeared in February last, and therefore before “Evolution, Old and New,” was written, and therefore independently of, and necessarily without reference to, that book. I do not doubt that this was actually the case, but have failed to obtain the edition which contains the passage above referred to, and several others which appear in the translation. I have a personal interest in this matter, and venture, therefore, to ask for the explanation which I do not doubt you will readily give me.—Yours faithfully, S. BUTLER. The following is Mr. Darwin’s answer:— _January_ 3, 1880. MY DEAR SIR,—Dr. Krause, soon after the appearance of his article in _Kosmos_ told me that he intended to publish it separately and to alter it considerably, and the altered MS. was sent to Mr. Dallas for translation. This is so common a practice that it never occurred to me to state that the article had been modified; but now I much regret that I did not do so. The original will soon appear in German, and I believe will be a much larger book than the English one; for, with Dr. Krause’s consent, many long extracts from Miss Seward were omitted (as well as much other matter), from being in my opinion superfluous for the English reader. I believe that the omitted parts will appear as notes in the German edition. Should there be a reprint of the English Life I will state that the original as it appeared in _Kosmos_ was modified by Dr. Krause before it was translated. I may add that I had obtained Dr. Krause’s consent for a translation, and had arranged with Mr. Dallas before your book was announced. I remember this because Mr. Dallas wrote to tell me of the advertisement.—I remain, yours faithfully, C. DARWIN.