Let us assume, for the moment, that the action of each impregnate germ is due to memory, which, as it were, pulsates anew in each succeeding generation, so that immediately on impregnation, the germ’s memory reverts to the last occasion on which it was in a like condition, and recognising the position, is at no loss what to do. It is plain that in all cases where there are two parents, that is to say, in the greater number of cases, whether in the vegetable or animal kingdoms, there must be two such last occasions, each of which will have an equal claim upon the attention of the new germ. Its memory would therefore revert to both, and though it would probably adhere more closely to the course which it took either as its father or its mother, and thus come out eventually male or female, yet it would be not a little influenced by the less potent memory.

And not only this, but each of the germs to which the memory of the new germ reverts, is itself imbued with the memories of its own parent germs, and these again with the memories of preceding generations, and so on ad infinitum; so that, ex hypothesi, the germ must become instinct with all these memories, epitomised as after long time, and unperceived though they may well be, not to say obliterated in part or entirely so far as many features are concerned, by more recent impressions. In this case, we must conceive of the impregnate germ as of a creature which has to repeat a performance already repeated before on countless different occasions, but with no more variation on the more recent ones than is inevitable in the repetition of any performance by an intelligent being.

Now if we take the most parallel case to this which we can find, and consider what we should ourselves do under such circumstances, that is to say, if we consider what course is actually taken by beings who are influenced by what we all call memory, when they repeat an already often-repeated performance, and if we find a very strong analogy between the course so taken by ourselves, and that which from whatever cause we observe to be taken by a living germ, we shall surely be much inclined to think that there must be a similarity in the causes of action in each case; and hence, to conclude, that the action of the germ is due to memory.

It will, therefore, be necessary to consider the general tendency of our minds in regard to impressions made upon us, and the memory of such impressions.

Deep impressions upon the memory are made in two ways, differing rather in degree than kind, but with two somewhat widely different results. They are made:—

I. By unfamiliar objects, or combinations, which come at comparatively long intervals, and produce their effect, as it were, by one hard blow. The effect of these will vary with the unfamiliarity of the impressions themselves, and the manner in which they seem likely to lead to a further development of the unfamiliar, i.e., with the question, whether they seem likely to compel us to change our habits, either for better or worse.

Thus, if an object or incident be very unfamiliar, as, we will say, a whale or an iceberg to one travelling to America for the first time, it will make a deep impression, though but little affecting our interests; but if we struck against the iceberg and were shipwrecked, or nearly so, it would produce a much deeper impression, we should think much more about icebergs, and remember much more about them, than if we had merely seen one. So, also, if we were able to catch the whale and sell its oil, we should have a deep impression made upon us. In either case we see that the amount of unfamiliarity, either present or prospective, is the main determinant of the depth of the impression.

As with consciousness and volition, so with sudden unfamiliarity. It impresses us more and more deeply the more unfamiliar it is, until it reaches such a point of impressiveness as to make no further impression at all; on which we then and there die. For death only kills through unfamiliarity—that is to say, because the new position, whatever it is, is so wide a cross as compared with the old one, that we cannot fuse the two so as to understand the combination; hence we lose all recognition of, and faith in, ourselves and our surroundings.

But however much we imagine we remember concerning the details of any remarkable impression which has been made us by a single blow, we do not remember as much or nearly as much as we think we do. The subordinate details soon drop out of mind. Those who think they remember even such a momentous matter as the battle of Waterloo recall now probably but half-a-dozen episodes, a gleam here, and a gleam there, so that what they call remembering the battle of Waterloo, is, in fact, little more than a kind of dreaming—so soon vanishes the memory of any unrepeated occurrence.

As for smaller impressions, there is very little of what happens to us in each week that will be in our memories a week hence; a man of eighty remembers few of the unrepeated incidents of his life beyond those of the last fortnight, a little here, and a little there, forming a matter of perhaps six weeks or two months in all, if everything that he can call to mind were acted over again with no greater fulness than he can remember it. As for incidents that have been often repeated, his mind strikes a balance of its past reminiscences, remembering the two or three last performances, and a general method of procedure, but nothing more.

If, then, the recollection of all that is not very novel, or very often repeated, so soon fades from our own minds, during what we consider as our single lifetime, what wonder that the details of our daily experience should find no place in that brief epitome of them which is all we can give in so small a volume as offspring?

If we cannot ourselves remember the hundred-thousandth part of what happened to us during our own childhood, how can we expect our offspring to remember more than what, through frequent repetition, they can now remember as a residuum, or general impression. On the other hand, whatever we remember in consequence of but a single impression, we remember consciously. We can at will recall details, and are perfectly well aware, when we do so, that we are recollecting. A man who has never seen death looks for the first time upon the dead face of some near relative or friend. He gazes for a few short minutes, but the impression thus made does not soon pass out of his mind. He remembers the room, the hour of the day or night, and if by day, what sort of a day. He remembers in what part of the room, and how disposed the body of the deceased was lying. Twenty years afterwards he can, at will, recall all these matters to his mind, and picture to himself the scene as he originally witnessed it.

The reason is plain; the impression was very unfamiliar, and affected the beholder, both as regards the loss of one who was dear to him, and as reminding him with more than common force that he will one day die himself. Moreover the impression was a simple one, not involving much subordinate detail; we have in this case, therefore, an example of the most lasting kind of impression that can be made by a single unrepeated event. But if we examine ourselves closely, we shall find that after a lapse of years we do not remember as much as we think we do, even in such a case as this; and that beyond the incidents above mentioned, and the expression upon the face of the dead person, we remember little of what we can so consciously and vividly recall.

II. Deep impressions are also made by the repetition, more or less often, of a feeble impression which, if unrepeated, would have soon passed out of our minds. We observe, therefore, that we remember best what we have done least often—any unfamiliar deviation, that is to say, from our ordinary method of procedure—and what we have done most often, with which, therefore, we are most familiar; our memory being mainly affected by the force of novelty and the force of routine—the most unfamiliar, and the most familiar, incidents or objects.

But we remember impressions which have been made upon us by force of routine, in a very different way to that in which we remember a single deep impression. As regards this second class, which comprises far the most numerous and important of the impressions with which our memory is stored, it is often only by the fact of our performance itself that we are able to recognise or show to others that we remember at all. We often do not remember how, or when, or where we acquired our knowledge. All we remember is, that we did learn, and that at one time and another we have done this or that very often.

As regards this second class of impressions we may observe:—

1. That as a general rule we remember only the individual features of the last few repetitions of the act—if, indeed, we remember this much. The influence of preceding ones is to be found only in the general average of the procedure, which is modified by them, but unconsciously to ourselves. Take, for example, some celebrated singer, or pianoforte player, who has sung the same air, or performed the same sonata several hundreds or, it may be, thousands of times: of the details of individual performances, he can probably call to mind none but those of the last few days, yet there can be no question that his present performance is affected by, and modified by, all his previous ones; the care he has bestowed on these being the secret of his present proficiency.

In each performance (the performer being supposed in the same state of mental and bodily health), the tendency will be to repeat the immediately preceding performances more nearly than remoter ones. It is the common tendency of living beings to go on doing what they have been doing most recently. The last habit is the strongest. Hence, if he took great pains last time, he will play better now, and will take a like degree of pains, and play better still next time, and so go on improving while life and vigour last. If, on the other hand, he took less pains last time, he will play worse now, and be inclined to take little pains next time, and so gradually deteriorate. This, at least, is the common everyday experience of mankind.

So with painters, actors, and professional men of every description; after a little while the memory of many past performances strikes a sort of fused balance in the mind, which results in a general method of procedure with but little conscious memory of even the latest performances, and with none whatever of by far the greater number of the remoter ones.

Still, it is noteworthy, that the memory of some even of these will occasionally assert itself, so far as we can see, arbitrarily, the reason why this or that occasion should still haunt us, when others like them are forgotten, depending on some cause too subtle for our powers of observation.

Even with such a simple matter as our daily dressing and undressing, we may remember some few details of our yesterday’s toilet, but we retain nothing but a general and fused recollection of the many thousand earlier occasions on which we have dressed, or gone to bed. Men invariably put the same leg first into their trousers—this is the survival of memory in a residuum; but they cannot, till they actually put on a pair of trousers, remember which leg they do put in first; this is the rapid fading away of any small individual impression.

The seasons may serve as another illustration; we have a general recollection of the kind of weather which is seasonable for any month in a year; what flowers are due about what time, and whether the spring is on the whole backward or early; but we cannot remember the weather on any particular day a year ago, unless some unusual incident has impressed it upon our memory. We can remember, as a general rule, what kind of season it was, upon the whole, a year ago, or perhaps, even two years; but more than this, we rarely remember, except in such cases as the winter of 1854–1855, or the summer of 1868; the rest is all merged.

We observe, then, that as regards small and often repeated impressions, our tendency is to remember best, and in most detail, what we have been doing most recently, and what in general has occurred most recently, but that the earlier impressions though forgotten individually, are nevertheless, not wholly lost.

2. When we have done anything very often, and have got into the habit of doing it, we generally take the various steps in the same order; in many cases this seems to be a sine qu non for our repetition of the action at all. Thus, there is probably no living man who could repeat the words of “God save the Queen” backwards, without much hesitation and many mistakes; so the musician and the singer must perform their pieces in the order of the notes as written, or at any rate as they ordinarily perform them; they cannot transpose bars or read them backwards, without being put out, nor would the audience recognise the impressions they have been accustomed to, unless these impressions are made in the accustomed order.

3. If, when we have once got well into the habit of doing anything in a certain way, some one shows us some other way of doing it, or some way which would in part modify our procedure, or if in our endeavours to improve, we have hit upon some new idea which seems likely to help us, and thus we vary our course, on the next occasion we remember this idea by reason of its novelty, but if we try to repeat it, we often find the residuum of our old memories pulling us so strongly into our old groove, that we have the greatest difficulty in repeating our performance in the new manner; there is a clashing of memories, a conflict, which if the idea is very new, and involves, so to speak, too sudden a cross—too wide a departure from our ordinary course—will sometimes render the performance monstrous, or baffle us altogether, the new memory failing to fuse harmoniously with the old. If the idea is not too widely different from our older ones, we can cross them with it, but with more or less difficulty, as a general rule in proportion to the amount of variation. The whole process of understanding a thing consists in this, and, so far as I can see at present, in this only.

Sometimes we repeat the new performance for a few times, in a way which shows that the fusion of memories is still in force; and then insensibly revert to the old, in which case the memory of the new soon fades away, leaving a residuum too feeble to contend against that of our many earlier memories of the same kind. If, however, the new way is obviously to our advantage, we make an effort to retain it, and gradually getting into the habit of using it, come to remember it by force of routine, as we originally remembered it by force of novelty. Even as regards our own discoveries, we do not always succeed in remembering our most improved and most striking performances, so as to be able to repeat them at will immediately: in any such performance we may have gone some way beyond our ordinary powers, owing to some unconscious action of the mind. The supreme effort has exhausted us, and we must rest on our oars a little, before we make further progress; or we may even fall back a little, before we make another leap in advance.

In this respect, almost every conceivable degree of variation is observable, according to differences of character and circumstances. Sometimes the new impression has to be made upon us many times from without, before the earlier strain of action is eliminated; in this case, there will long remain a tendency to revert to the earlier habit. Sometimes, after the impression has been once made, we repeat our old way two or three times, and then revert to the new, which gradually ousts the old; sometimes, on the other hand, a single impression, though involving considerable departure from our routine, makes its mark so deeply that we adopt the new at once, though not without difficulty, and repeat it in our next performance, and henceforward in all others; but those who vary their performance thus readily will show a tendency to vary subsequent performances according as they receive fresh ideas from others, or reason them out independently. They are men of genius.

This holds good concerning all actions which we do habitually, whether they involve laborious acquirement or not. Thus, if we have varied our usual dinner in some way that leaves a favourable impression upon our minds, so that our dinner may, in the language of the horticulturist, be said to have “sported,” our tendency will be to revert to this particular dinner either next day, or as soon as circumstances will allow, but it is possible that several hundred dinners may elapse before we can do so successfully, or before our memory reverts to this particular dinner.

4. As regards our habitual actions, however unconsciously we remember them, we, nevertheless, remember them with far greater intensity than many individual impressions or actions, it may be of much greater moment, that have happened to us more recently. Thus, many a man who has familiarised himself, for example, with the odes of Horace, so as to have had them at his fingers’ ends as the result of many repetitions, will be able years hence to repeat a given ode, though unable to remember any circumstance in connection with his having learnt it, and no less unable to remember when he repeated it last. A host of individual circumstances, many of them not unimportant, will have dropped out of his mind, along with a mass of literature read but once or twice, and not impressed upon the memory by several repetitions; but he returns to the well-known ode with so little effort, that he would not know that he was remembering unless his reason told him so. The ode seems more like something born with him.

We observe, also, that people who have become imbecile, or whose memory is much impaired, yet frequently retain their power of recalling impression which have been long ago repeatedly made upon them.

In such cases, people are sometimes seen to forget what happened last week, yesterday, or an hour ago, without even the smallest power of recovering their recollection; but the oft repeated earlier impression remains, though there may be no memory whatever of how it came to be impressed so deeply. The phenomena of memory, therefore, are exactly like those of consciousness and volition, in so far as that the consciousness of recollection vanishes, when the power of recollection has become intense. When we are aware that we are recollecting, and are trying, perhaps hard, to recollect, it is a sign that we do not recollect utterly. When we remember utterly and intensely, there is no conscious effort of recollection; our recollection can only be recognised by ourselves and others, through our performance itself, which testifies to the existence of a memory, that we could not otherwise follow or detect.

5. When circumstances have led us to change our habits of life—as when the university has succeeded school, or professional life the university—we get into many fresh ways, and leave many old ones. But on revisiting the old scene, unless the lapse of time has been inordinately great, we experience a desire to revert to old habits. We say that old associations crowd upon us. Let a Trinity man, after thirty years absence from Cambridge, pace for five minutes in the cloister of Neville’s Court, and listen to the echo of his footfall, as it licks up against the end of the cloister, or let an old Johnian stand wherever he likes in the third Court of St. John’s, in either case he will find the thirty years drop out of his life, as if they were half-an-hour; his life will have rolled back upon itself, to the date when he was an undergraduate, and his instinct will be to do almost mechanically, whatever it would have come most natural to him to do, when he was last there at the same season of the year, and the same hour of the day; and it is plain this is due to similarity of environment, for if the place he revisits be much changed, there will be little or no association.

So those who are accustomed at intervals to cross the Atlantic, get into certain habits on board ship, different to their usual ones. It may be that at home they never play whist; on board ship they do nothing else all the evening. At home they never touch spirits; on the voyage they regularly take a glass of something before they go to bed. They do not smoke at home; here they are smoking all day. Once the voyage is at an end, they return without an effort to their usual habits, and do not feel any wish for cards, spirits, or tobacco. They do not remember yesterday, when they did want all these things; at least, not with such force as to be influenced by it in their desires and actions; their true memory—the memory which makes them want, and do, reverts to the last occasion on which they were in circumstances like their present; they therefore want now what they wanted then, and nothing more; but when the time comes for them to go on shipboard again, no sooner do they smell the smell of the ship, than their real memory reverts to the times when they were last at sea, and striking a balance of their recollections, they smoke, play cards, and drink whisky and water.

We observe it then as a matter of the commonest daily occurrence within our own experience, that memory does fade completely away, and recur with the recurrence of surroundings like those which made any particular impression in the first instance. We observe that there is hardly any limit to the completeness and the length of time during which our memory may remain in abeyance. A smell may remind an old man of eighty of some incident of his childhood, forgotten for nearly as many years as he has lived. In other words, we observe that when an impression has been repeatedly made in a certain sequence on any living organism—that impression not having been prejudicial to the creature itself—the organism will have a tendency, on reassuming the shape and conditions in which it was when the impression was last made, to remember the impression, and therefore to do again now what it did then; all intermediate memories dropping clean out of mind, so far as they have any effect upon action.

6. Finally, we should note the suddenness and apparent caprice with which memory will assert itself at odd times; we have been saying or doing this or that, when suddenly a memory of something which happened to us, perhaps in infancy, comes into our head; nor can we in the least connect this recollection with the subject of which we have just been thinking, though doubtless there has been a connection, too rapid and subtle for our apprehension.

The foregoing phenomena of memory, so far as we can judge, would appear to be present themselves throughout the animal and vegetable kingdoms. This will be readily admitted as regards animals; as regards plants it may be inferred from the fact that they generally go on doing what they have been doing most lately, though accustomed to make certain changes at certain points in their existence. When the time comes for these changes, they appear to know it, and either bud forth into leaf or shed their leaves, as the case may be. If we keep a bulb in a paper bag it seems to remember having been a bulb before, until the time comes for it to put forth roots and grow. Then, if we supply it with earth and moisture, it seems to know where it is, and to go on doing now whatever it did when it was last planted; but if we keep it in the bag too long, it knows that it ought, according to its last experience, to be treated differently, and shows plain symptoms of uneasiness; it is distracted by the bag, which makes it remember its bulbhood, and also by the want of earth and water, without which associations its memory of its previous growth cannot be duly kindled. Its roots, therefore, which are most accustomed to earth and water, do not grow; but its leaves, which do not require contact with these things to jog their memory, make a more decided effort at development—a fact which would seem to go strongly in favour of the functional independence of the parts of all but the very simplest living organisms, if, indeed, more evidence were wanted in support of this.