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.

VIII. If, then, memory depends on association, we should expect two corresponding phenomena in the case of plants and animals—namely, that they should show a tendency to resume feral habits on being turned wild after several generations of domestication, and also that peculiarities should tend to show themselves at a corresponding age in the offspring and in the parents. As regards the tendency to resume feral habits, Mr. Darwin, though apparently of opinion that the tendency to do this has been much exaggerated, yet does not doubt that such a tendency exists, as shown by well authenticated instances. He writes: “It has been repeatedly asserted in the most positive manner by various authors that feral animals and plants invariably return to their primitive specific type.”

This shows, at any rate, that there is a considerable opinion to this effect among observers generally.

He continues: “It is curious on what little evidence this belief rests. Many of our domesticated animals could not subsist in a wild state,”—so that there is no knowing whether they would or would not revert. “In several cases we do not know the aboriginal parent species, and cannot tell whether or not there has been any close degree of reversion.” So that here, too, there is at any rate no evidence against the tendency; the conclusion, however, is that, notwithstanding the deficiency of positive evidence to warrant the general belief as to the force of the tendency, yet “the simple fact of animals and plants becoming feral does cause some tendency to revert to the primitive state,” and he tells us that “when variously-coloured tame rabbits are turned out in Europe, they generally re-acquire the colouring of the wild animal;” “there can be no doubt,” he says, “that this really does occur,” though he seems inclined to account for it by the fact that oddly-coloured and conspicuous animals would suffer much from beasts of prey and from being easily shot. “The best known case of reversion:” he continues, “and that on which the widely-spread belief in its universality apparently rests, is that of pigs. These animals have run wild in the West Indies, South America, and the Falkland Islands, and have everywhere re-acquired the dark colour, the thick bristles, and great tusks of the wild boar; and the young have re-acquired longitudinal stripes.” And on page 22 of “Plants and Animals under Domestication” (vol. ii. ed. 1875) we find that “the re-appearance of coloured, longitudinal stripes on young feral pigs cannot be attributed to the direct action of external conditions. In this case, and in many others, we can only say that any change in the habits of life apparently favours a tendency, inherent or latent, in the species to return to the primitive state.” On which one cannot but remark that though any change may favour such tendency, yet the return to original habits and surroundings appears to do so in a way so marked as not to be readily referable to any other cause than that of association and memory—the creature, in fact, having got into its old groove, remembers it, and takes to all its old ways.

As regards the tendency to inherit changes (whether embryonic, or during post-natal development as ordinarily observed in any species), or peculiarities of habit or form which do not partake of the nature of disease, it must be sufficient to refer the reader to Mr. Darwin’s remarks upon this subject (“Plants and Animals Under Domestication,” vol. ii. pp. 51–57, ed. 1875). The existence of the tendency is not likely to be denied. The instances given by Mr. Darwin are strictly to the point as regards all ordinary developmental and metamorphic changes, and even as regards transmitted acquired actions, and tricks acquired before the time when the offspring has issued from the body of the parent, or on an average of many generations does so; but it cannot for a moment be supposed that the offspring knows by inheritance anything about what happens to the parent subsequently to the offspring’s being born. Hence the appearance of diseases in the offspring, at comparatively late periods in life, but at the same age as, or earlier, than in the parents, must be regarded as due to the fact that in each case the machine having been made after the same pattern (which is due to memory), is liable to have the same weak points, and to break down after a similar amount of wear and tear; but after less wear and tear in the case of the offspring than in that of the parent, because a diseased organism is commonly a deteriorating organism, and if repeated at all closely, and without repentance and amendment of life, will be repeated for the worse. If we do not improve, we grow worse. This, at least, is what we observe daily.

Nor again can we believe, as some have fancifully imagined, that the remembrance of any occurrence of which the effect has been entirely, or almost entirely mental, should be remembered by offspring with any definiteness. The intellect of the offspring might be affected, for better or worse, by the general nature of the intellectual employment of the parent; or a great shock to a parent might destroy or weaken the intellect of the offspring; but unless a deep impression were made upon the cells of the body, and deepened by subsequent disease, we could not expect it to be remembered with any definiteness, or precision. We may talk as we will about mental pain, and mental scars, but after all, the impressions they leave are incomparably less durable than those made by an organic lesion. It is probable, therefore, that the feeling which so many have described, as though they remembered this or that in some past existence, is purely imaginary, and due rather to unconscious recognition of the fact that we certainly have lived before, than to any actual occurrence corresponding to the supposed recollection.

And lastly, we should look to find in the action of memory, as between one generation and another, a reflection of the many anomalies and exceptions to ordinary rules which we observe in memory, so far as we can watch its action in what we call our own single lives, and the single lives of others. We should expect that reversion should be frequently capricious—that is to say, give us more trouble to account for than we are either able or willing to take. And assuredly we find it so in fact. Mr. Darwin—from whom it is impossible to quote too much or too fully, inasmuch as no one else can furnish such a store of facts, so well arranged, and so above all suspicion of either carelessness or want of candour—so that, however we may differ from him, it is he himself who shows us how to do so, and whose pupils we all are—Mr. Darwin writes: “In every living being we may rest assured that a host of long-lost characters lie ready to be evolved under proper conditions” (does not one almost long to substitute the word “memories” for the word “characters?”) “How can we make intelligible, and connect with other facts, this wonderful and common capacity of reversion—this power of calling back to life long-lost characters?” (“Plants and Animals,” &c., vol. ii. p. 369, ed. 1875). Surely the answer may be hazarded, that we shall be able to do so when we can make intelligible the power of calling back to life long-lost memories. But I grant that this answer holds out no immediate prospect of a clear understanding.

One word more. Abundant facts are to be found which point inevitably, as will appear more plainly in the following chapter, in the direction of thinking that offspring inherits the memories of its parents; but I know of no single fact which suggests that parents are in the smallest degree affected (other than sympathetically) by the memories of their offspring after that offspring has been born. Whether the unborn offspring affects the memory of the mother in some particulars, and whether we have here the explanation of occasional reversion to a previous impregnation, is a matter on which I should hardly like to express an opinion now. Nor, again, can I find a single fact which seems to indicate any memory of the parental life on the part of offspring later than the average date of the offspring’s quitting the body of the parent.