But if, according to Professor Hering, the personal identity of the single life consists in the uninterruptedness of vibrations, so also do the phenomena of heredity. For not only may vibrations of a certain violence or character be persistent unperceived for many years in a living body, and communicate themselves to the matter it has assimilated, but they may, and will, under certain circumstances, extend to the particle which is about to leave the parent body as the germ of its future offspring. In this minute piece of matter there must, if Professor Hering is right, be an infinity of rhythmic undulations incessantly vibrating with more or less activity, and ready to be set in more active agitation at a moment’s warning, under due accession of vibration from exterior objects. On the occurrence of such stimulus, that is to say, when a vibration of a suitable rhythm from without concurs with one within the body so as to augment it, the agitation may gather such strength that the touch, as it were, is given to a house of cards, and the whole comes toppling over. This toppling over is what we call action; and when it is the result of the disturbance of certain usual arrangements in certain usual ways, we call it the habitual development and instinctive characteristics of the race. In either case, then, whether we consider the continued identity of the individual in what we call his single life, or those features in his offspring which we refer to heredity, the same explanation of the phenomena is applicable. It follows from this as a matter of course, that the continuation of life or personal identity in the individual and the race are fundamentally of the same kind, or, in other words, that there is a veritable prolongation of identity or oneness of personality between parents and offspring. Professor Hering reaches his conclusion by physical methods, while I reached mine, as I am told, by metaphysical. I never yet could understand what “metaphysics” and “metaphysical” mean; but I should have said I reached it by the exercise of a little common sense while regarding certain facts which are open to every one. There is, however, so far as I can see, no difference in the conclusion come to. The view which connects memory with vibrations may tend to throw light upon that difficult question, the manner in which neuter bees acquire structures and instincts, not one of which was possessed by any of their direct ancestors. Those who have read “Life and Habit” may remember, I suggested that the food prepared in the stomachs of the nurse-bees, with which the neuter working bees are fed, might thus acquire a quasi-seminal character, and be made a means of communicating the instincts and structures in question. {58} If assimilation be regarded as the receiving by one substance of the rhythms or undulations from another, the explanation just referred to receives an accession of probability.