I return enclosed: if you write, thank Mr. Kingsley for thinking of letting me see the sound sense of an Eastern potentate. (154/1. Kingsley's letter to Huxley, dated December 20th, 1862, contains a story or parable of a heathen Khan in Tartary who was visited by a pair of proselytising Moollahs. The first Moollah said: "Oh! Khan, worship my God. He is so wise that he made all things." But Moollah No. 2 won the day by pointing out that his God is "so wise that he makes all things make themselves.") All that I said about the little book (154/2. The six "Lectures to Working Men," published in six pamphlets and in book-form in 1863. Mr. Huxley considered that Mr. Darwin's argument required the production by man's selection of breeds which should be mutually infertile, and thus resemble distinct species physiologically as well as morphologically.) is strictly my opinion; it is in every way excellent, and cannot fail to do good the wider it is circulated. Whether it is worth your while to give up time to it is another question for you alone to decide; that it will do good for the subject is beyond all question. I do not think a dunce exists who could not understand it, and that is a bold saying after the extent to which I have been misunderstood. I did not understand what you required about sterility: assuredly the facts given do not go nearly so far. We differ so much that it is no use arguing. To get the degree of sterility you expect in recently formed varieties seems to me simply hopeless. It seems to me almost like those naturalists who declare they will never believe that one species turns into another till they see every stage in process. I have heard from Tegetmeier, and have given him the result of my crosses of the birds which he proposes to try, and have told him how alone I think the experiment could be tried with the faintest hope of success--namely, to get, if possible, a case of two birds which when paired were unproductive, yet neither impotent. For instance, I had this morning a letter with a case of a Hereford heifer, which seemed to be, after repeated trials, sterile with one particular and far from impotent bull, but not with another bull. But it is too long a story--it is to attempt to make two strains, both fertile, and yet sterile when one of one strain is crossed with one of the other strain. But the difficulty...would be beyond calculation. As far as I see, Tegetmeier's plan would simply test whether two existing breeds are now in any slight degree sterile; which has already been largely tested: not that I dispute the good of re-testing. LETTER 155. TO HUGH FALCONER.