Now, as to atavism, or breeding back. In the ancestral bottles called men and women there are millions of different kinds of beads. And it sometimes happens that a particular kind of bead (or quality) which has lain dormant for a long time--perhaps for a thousand years--will crop up in a new mixing that goes to make a "child-bottle," and so that child may be less like its own parents than like some ancestor who has been dead and forgotten for centuries. In the case of the man with the seven ape muscles, mentioned by Darwin, the breeding back must have reached millions of years. This "lying doggo," or inactive, of some hereditary trait, may be likened to the action of a kaleidoscope. We do not see all the fragments of coloured glass at every turn. But they are all there. We do not see the same pattern twice; yet the patterns are made almost of the same colours and the same pieces. And now I think we have got a clear idea of the meanings of the words "heredity," "variation," and "atavism," and the most timid reader will not be afraid of them any more. There is no need, for our purpose, to wrestle with severe science. The reader may find for himself all about "pangenesis" in Darwin, and about the "germ plasm" in Weissmann. Here we will not tax our memories with such weird words as "biophors," "gemmules," "ids," "idents," and "determinants." Our similes of beads, tartans, and cards will serve us well enough. The only objection to our similes is that they are too simple. The mixture of bloods in descent is very much more extensive | than our mixture of cards or beads. If we trace a child's descent back only four generations we find that he has no less than thirty fore-parents belonging to sixteen different families. Another generation would reach thirty-two families. If we go back to twenty generations we find the number of families drawn upon to be over a million. But Darwin speaks of "thousands of generations." Does not! this suggest the wonderful possibilities of variation and atavism? Imagine the variety of character and physique in a city like London. Then remember that each one of us is descended from more ancestors, and of much wider varieties, than all the population of London. And to hold a man answerable for his inheritance from those motley myriads of men and women is to hold him answerable for the natures and the actions of millions of human beings whom he never saw, of whom he never heard. We all know that the different races of men differ from each other in colour, in features, and in capacity. We have only to think for a little of the Japanese, the Americans, the Spaniards, and the Swedes, to feel the full force of the term "racial characteristics." We know that there is a great difference between the Irish and the Scotch. We know that there is a great difference between the Italians and the Dutch. We know the strongly marked peculiarities of the Jews and the Greeks.