Lawson Tait says (p. 60)--'The process of growth of the ovum after impregnation can be followed only after the assumption either expressed or _unconsciously accepted_ of such a hypothesis as is contained in Mr. Darwin's "Pangenesis;"' and it is interesting, as showing the truth of the remark, to compare, for example, p. 29 of the other pamphlet--for, of course, 'Pangenesis' assumes the truth of the persistence of force as the prime condition of its possibility. If ever I have occasion to prepare a paper about heredity, I think it would be worth while to point out the absurdity of thinking that we explain anything by vague allusions to the most ultimate generalisation of science. We might just as well say that Canadian institutions resemble British ones because force is persistent. This doubtless is the ultimate reason, but our explanation would be scientifically valueless if we neglected to observe that the Canadian colony was founded by British individuals. The leaf from 'Nature' arrived last night. I had previously intended to try mangold-wurzel, as I hear it has well-marked varieties. The reference, therefore, will be valuable to me. Before closing, I should like to take this opportunity of thanking you again for the very pleasant time I spent at Down. The place was one which I had long wished to see, and now that I have seen it, I am sure it will ever remain one of the most agreeable and interesting of memory's pictures. With kind regards to Mrs. Darwin, I remain, very sincerely and most respectfully yours, GEO. J. ROMANES. _To Professor E. Schäfer._ Dunskaith, Ross-shire. My dear Schäfer,--I am glad to hear that your rest has been beneficial, and also about all the other news you give. I should like to have your opinion about the meaning of the following facts. In Sarsia gentle irritation of a tentacle or an eye-speck causes the _polypite_ to respond, but not the bell (stronger irritation, of course, causes both to respond); this seems to show that there are nervous connections between the eye-specks and the polypite. By introducing cuts between former and latter, these connections may be destroyed--the tolerance of the tissue to such sections being variable in different cases, but never being anything remarkable. So far, then, the matter seems favourable to the nerve-plexus theory.