VII. We should also expect that the memory of animals, as regards their earlier existences, was solely stimulated by association. For we find, from Prof. Bain, that “actions, sensations, and states of feeling occurring together, or in close succession, tend to grow together or cohere in such a way that when any one of them is afterwards presented to the mind, the others are apt to be brought up in idea” (“The Senses and the Intellect,” 2d ed. 1864, p. 332). And Prof. Huxley says (“Elementary Lessons in Physiology,” 5th ed. 1872, p. 306), “It may be laid down as a rule that if any two mental states be called up together, or in succession, with due frequency and vividness, the subsequent production of the one of them will suffice to call up the other, _and that whether we desire it or not_.” I would go one step further, and would say not only whether we desire it or not, but _whether we are aware that the idea has ever before been called up in our minds or not_. I should say that I have quoted both the above passages from Mr. Darwin’s “Expression of the Emotions” (p. 30, ed. 1872). We should, therefore, expect that when the offspring found itself in the presence of objects which had called up such and such ideas for a sufficient number of generations, that is to say, “with due frequency and vividness”—it being of the same age as its parents were, and generally in like case as when the ideas were called up in the minds of the parents—the same ideas should also be called up in the minds of the offspring “_whether they desire it or not_;” and, I would say also, “whether they recognise the ideas as having ever before been present to them or not.” I think we might also expect that no other force, save that of association, should have power to kindle, so to speak, into the flame of action the atomic spark of memory, which we can alone suppose to be transmitted from one generation to another. That both plants and animals do as we should expect of them in this respect is plain, not only from the performance of the most intricate and difficult actions—difficult both physically and intellectually—at an age, and under circumstances which preclude all possibility of what we call instruction, but from the fact that deviations from the parental instinct, or rather the recurrence of a memory, unless in connection with the accustomed train of associations, is of comparatively rare occurrence; the result, commonly, of some one of the many memories about which we know no more than we do of the memory which enables a cat to find her way home after a hundred-mile journey by train, and shut up in a hamper, or, perhaps even more commonly, of abnormal treatment.