If you are acquainted with my new theory of 'Physiological Selection' (published in 'Journ. Lin. Soc.' 1886) you will understand why I regard your facts as furnishing first-rate material for testing that theory. If you cannot get access to my paper, I will send you a copy on my return to London in December. My object in now writing--over and above that of thanking you for your paper--is to ask whether you yourself, or any other American naturalist whom you may know, would not feel it well worth while to try some experiments on the hybridisation of the peculiar species. Although I agree with you in thinking it probable that many of these species may be 'remnants,' I also think it abundantly possible that some of them may be merely evolved forms. A botanist on the spot might be able to determine, by intelligent comparison, which of the peculiar species are most probably of the last-mentioned character. These he might choose for his experiments on hybridisation. And I should expect him to find marked evidence of mutual sterility between closely allied unique species growing on the same island, with possibly unimpaired fertility between allied species growing on different islands. If this anticipation should be realised by experiment, the fact would go far to prove my theory. Even if you do not happen to know of any botanist who would care to undertake this experimental research, you might possibly know of some one who would gather and transmit seeds for me to grow in hothouses here. I shall be much interested to hear what you think of these proposals, and meanwhile remain, Yours truly, G. J. ROMANES. Geanies. My dear Sir,--Your book I will look forward to with much interest, and certainly not least so to your treatment of that very comprehensive question--'What then?' I will send you a copy of my paper on Physiological Selection as soon as I return to London, which will be about Christmas. With many thanks for your kindness, I remain, yours truly, G. J. ROMANES. May 7, 1888. My dear Sir,--Many thanks for sending me a copy of your book,[66] which seems to me everywhere admirable. Of course, I am particularly glad that you think with me so much on physiological selection, but even apart from this, the work is, to my mind, one of the most clearly thought out that I have met with in Darwinian literature. I have sent it on to 'Nature' for review, understanding from the office that a copy had not then been received. But for your kind mention of myself, I should have reviewed it. A most remarkable paper has been sent to the Linnean Society by a Mr. Gulick on 'Divergent Evolution,' for the publication of which in the 'Journal' you might look out. G. J. ROMANES. January 21, 1889. My dear Sir,--I should like you to set your lucid wits to work upon the following questions, and let me know whether you can devise any answers.