Thus, in a recent discussion on inheritance in a Presidential Address to the British Association, to which I have already alluded, the writer with whose explanation I have just been dealing states that he thinks it "unlikely" that the factors of inheritance are "in any simple or literal sense material particles," and proceeds thus: "I suspect rather that their properties depend on some phenomenon of arrangement." Now, in the first place, this is no explanation at all, for the mechanism of inheritance must be either material or immaterial. If there is a phenomenon of "arrangement" there must be something to be "arranged," and this something can hardly be other than material if it is to be "arranged" at all. But let that pass. What is far more important is to remember that if a thing is to be "arranged" there must be somebody to "arrange" it, for chance-medley cannot "arrange" anything in an orderly manner; or if it could do so once, cannot be supposed capable of doing it a second time in a precisely similar manner, not to say capable of doing it countless thousands of times. If we go into a great museum our first idea, perhaps our last, concerns the arrangement found therein. But it may safely be said that no sane person ever entertained that idea without being perfectly aware that the arrangement was made by human hands, controlled, in the last resort, by the brain of the curator of the museum. Now, in a sense, the living body is a museum containing specimens of different kinds of cells. There are brain-cells, liver-cells, bone-cells, scores of different varieties of cells, and all of them, so to speak, are arranged in their appropriate cases.