I write to thank you for the slip about graft hybrids, and to say that as yet I have obtained no results myself. This place is too far north to admit of the seeds ripening properly after the plants have been thrown back several weeks by the operation. This applies especially to onions, so next year--the neck of Medusæ having now been broken--I intend to wait in London till all the grafting and planting out is finished. I do not think you will regret my not having followed such a course this year when you come to read the paper I am now writing. I never did such a successful four months' work, and if as many years suffice to answer all the burning questions that are raised by it, I think they will require to be years well spent. And this makes me remember that I have to apologise for the inordinate time I have kept your copy of Professor Häckel's essay on Perigenesis. Since you sent it I have scarcely had any time for reading, and as you said there was no hurry about returning it, I have let it stand over till this paper is off my hands. Lankester seems to have doubled up Slade in fine style. I suppose the latter has always trusted to his customers not liking to resort to violent methods. His defence in the 'Times' about the locked slates was unusually weak. 'Once a thief always a thief' applies, I suppose, to his case; but it is hard to understand how Wallace could not have seen him inverting the table on his head. In this we have another of those perplexing contradictions with which the whole subject appears to be teeming. I do hope next winter to settle for myself the simple issue between Ghost _versus_ Goose. Very sincerely and most respectfully yours, GEO. J. ROMANES. _To C. Darwin, Esq._ 18 Cornwall Terrace. Professor Häckel's paper on the Medusæ is called 'Beitrag zur Naturgeschichte der Hydromedusen' (Leipzig, 1865). Professor Huxley has lent me his copy, but says he wants it returned in a week or two. I ought certainly to have the work by me next summer, so I thought that if you happen to have it and can spare it till next autumn, I need not send to Germany for it, remembering what you said when I last saw you. I should also much like to see the other paper of Häckel's about cutting up the ova of Medusæ.