I do not say this either in blind admiration or in criticism, but as the expression of a plain fact. Posterity will turn to this work when, either in hostility or in sympathy, it wishes to appreciate Haeckel.[3] Footnote 2: This work of Professor Haeckel’s has not been translated into English. [Trans.] Footnote 3: Professor Huxley described the _General Morphology_ as “one of the greatest scientific works ever published.” [Trans.] His contemporaries did not accept the work without difficulty. It came out without noise, exerted a tremendous influence in a quiet way, and at last disappeared altogether from the bookshops. It is still attacked, but has never been refuted. At libraries one finds, as I know from experience, that it is always “out,” and therefore must be read continually. It is found occasionally at second-hand booksellers; an antiquarian price running to five pounds and more is put on it, after forty years’ active production on the part of its author. At present you could count on your fingers the German works that have this distinction of being highly priced and out of print. One such is Vischer’s _Æsthetics_, and another is the first edition of Gottfried Keller’s _Green Henry_. Keller had threatened any one who ever attempted to republish this first edition (afterwards modified but not improved by him) that their hand would not rest quietly in the grave. But the price of the work went up amongst antiquarians. I feel, in speaking of Haeckel’s _General Morphology_, that I am describing a book which has become so rare that one must treat it as something new, a codex that is only accessible to a few. It is certainly not known to the general reader. Let me endeavour in a few words to give a general idea of the chief contents of the work.