I have left your kind letter of March 11 too long unacknowledged. Now I have to thank you for a copy of the “Phytographie,” which interests me exceedingly. I have also to say that my plans for the year are so far settled that I have engaged passage for Mrs. Gray and myself in a Cunard steamer from Boston for Liverpool on the 4th of September, the earliest date on which we could leave home. But, greatly as you tempt me, and much as I should like to see you early, we cannot reach Switzerland this autumn.... I should hope we might see you in early summer. So, pray, keep yourself well and strong till then. About the “Phytographie:” I shall have much to write, when I read the book, which as yet I have only glanced at. About dextrorsum and sinistrorsum: I think it is not quite true that the innovators have not given any account of the grounds on which they rest. Mine are expressed, I believe, in two or three notes in “American Journal of Science,” and are summed up in my “Botanical Text-Book,” last edition, p. 516, referred to in the glossary and index. I think that the analogy of the right-handed screw indicates how the world in general regard it, ab extra. There is a sensible note on the question in the late Clerk-Maxwell’s “Treatise on Electricity,” vol. 1,--the reference is not at hand at this moment. It takes, essentially, our (my) view as it seems to me; but it refers to a similar confusion between the mathematicians and the physicists. I wish you had gone on to illustrate more of the words which have been changed or confused in meaning; for example, “pistillum,” “cyme,” etc. It is a pity that the terms of nomenclature had not been rearranged by Roeper[113] so as to conflict less with those of Linnæus and the general botanical use. We have had our centennial of the American Academy; a pleasant reunion.... Mr. Winthrop gave a good public address. I get only slowly on with the Compositæ; my interruptions and distractions are many and great. Fortunately I am in perfect health; am outliving my chronic catarrh. I hope you may do so also! June 28, 1880. Yours of the 15th is duly received, with your pleasant remarks on my lectures.[114] Professor Bourier is very welcome, and will please me by using any part of them he chooses. I should like to see how they would read in French. CHAPTER VIII. FINAL JOURNEYS AND WORK. 1880-1888. Dr. Gray sailed for Europe with Mrs. Gray early in September, 1880. He went especially to study herbaria for his new volume of the “Synoptical Flora,” and saw almost every collection of importance, giving especial attention to the subject of asters. The autumn was spent in western France and Spain, and in Madrid he looked over the herbarium there. He declared nobody had ever had so many asters pass through his hands as he had had!