I was quite uneasy at getting no attack from the "Witness," thinking I must have overestimated the impression that I had made, and the favourableness of the reception of what I said. But the raving of the "Witness" is clear testimony that my notion was correct. I shall send a short reply to the "Scotsman" for the purpose of further advertising the question. With regard to what are especially your doctrines, I spoke much more favourably than I am reported to have done. I expressed no doubt as to their ultimate establishment, but as I particularly wished not to be misrepresented as an advocate trying to soften or explain away real difficulties, I did not in speaking enter into the details of what is to be said in diminishing the weight of the hybrid difficulty. All this will be put fully when I print the Lecture. The arguments put in your letter are those which I have urged to other people--of the opposite side--over and over again. I have told my students that I entertain no doubt that twenty years' experiments on pigeons conducted by a skilled physiologist, instead of by a mere breeder, would give us physiological species sterile inter se, from a common stock (and in this, if I mistake not, I go further than you do yourself), and I have told them that when these experiments have been performed I shall consider your views to have a complete physical basis, and to stand on as firm ground as any physiological theory whatever. It was impossible for me, in the time I had, to lay all this down to my Edinburgh audience, and in default of full explanation it was far better to seem to do scanty justice to you. I am constitutionally slow of adopting any theory that I must needs stick by when I have gone in for it; but for these two years I have been gravitating towards your doctrines, and since the publication of your primula paper with accelerated velocity. By about this time next year I expect to have shot past you, and to find you pitching into me for being more Darwinian than yourself. However, you have set me going, and must just take the consequences, for I warn you I will stop at no point so long as clear reasoning will carry me further. My wife and I were very grieved to hear you had had such a sick house, but I hope the change in the weather has done you all good. Anything is better than the damp warmth we had. I will take great care of the three "Barriers." [A pamphlet called "The Three Barriers" by G.R., being notes on Mr. Darwin's "Origin of Species" 1861, 8vo." Habitat, structure, and procreative power are given as these three barriers to Darwinism, against which natural theology takes its stand on Final Causes.] I wanted to cut it up in the "Saturday," but how I am to fulfil my benevolent intentions--with five lectures a week--a lecture at the Royal Institution and heaps of other things on my hands, I don't know. Ever yours faithfully, T.H. Huxley.