I was sorry to have to send an excuse by Tyndall the other day, but I found I must finish the Pyrosoma paper, and all last Tuesday was devoted to it, and I fear the next after will have the like fate. It constantly becomes more and more difficult to me to FINISH things satisfactorily. [To Hooker also he writes a few days later:--] I hope your ear is better; take care of yourself, there's a good fellow. I can't do without you these twenty years. We have a devil of a lot to do in the way of smiting the Amalekites. [Between two men who seldom spoke of their feelings, but let constant intercourse attest them, these words show more than the practical side of their friendship, their community of aims and interests. Quick, strong-willed, and determined as they both were, the fact that they could work together for over forty years without the shadow of a misunderstanding, presupposes an unusually strong friendship firmly based upon mutual trust and respect as well as liking, the beginning of which Sir J. Hooker thus describes:-- My first meeting your father was in 1851, shortly after his return from the "Rattlesnake" voyage with Captain Stanley. Hearing that I had paid some attention to marine zoology during the voyage of the Antarctic Expedition, he was desirous of showing me the results of his studies of the Oceanic Hydrozoa, and he sought me out in consequence. This and the fact that we had both embarked in the Naval service in the same capacity as medical officers and with the same object of scientific research, naturally led to an intimacy which was undisturbed by a shadow of a misunderstanding for nearly forty-five following years. Curiously enough, our intercourse might have dated from an earlier period by nearly six years had I accepted an appointment to the "Rattlesnake" offered me by Captain Stanley, which, but for my having arranged for a journey to India, might have been accepted. Returning to the purpose of our interview, the researches Mr. Huxley laid before me were chiefly those on the Salpae, a much misunderstood group of marine Hydrozoa. Of these I had amused myself with making drawings during the long and often weary months passed at sea on board the "Erebus," but having other subjects to attend to, I had made no further study of them than as consumers of the vegetable life (Diatoms) of the Antarctic Ocean. Hence his observations on their life-history, habits, and affinities were on almost all points a revelation to me, and I could not fail to recognise in their author all the qualities possessed by a naturalist of commanding ability, industry, and power of exposition. Our interviews, thus commenced, soon ripened into a friendship, which led to an arrangement for a monthly meeting, and in the informal establishment of a club of nine, the other members of which were, Mr. Busk, Dr. Frankland, Mr. Hirst, Sir J. Lubbock, Mr. Herbert Spencer, Dr. Tyndall, and Mr. Spottiswoode.