being more perfect, through a larger number (generally) of repetitions of the act that is remembered; there is therefore a less proportionate difference in respect of the number of recollections of this particular act between the most recent actor and the most recent but one. This is why very old civilizations, as those of many insects, and the greater number of now living organisms, appear to the eye not to change at all.

For example, if an action has been performed only ten times, we will say by A, B, C, etc., who are similar in all respects, except that A acts without recollection, B with recollection of A's action, C with recollection of both B's and A's, while J remembers the course taken by A, B, C, D, E, F, G, H, and I-the possession of a memory by B will indeed so change his action, as compared with A's, that it may well be hardly recognizable. We saw this in our example of the clerk who asked the policeman the way to the eating-house on one day, but did not ask him the next, because he remembered; but C's action will not be so different from B's as B's from A's, for though C will act with a memory of two occasions on which the action has been performed, while B recollects only the original performance by A, yet B and C both act with the guidance of a memory and experience of some kind, while A acted without any. Thus the clerk referred to in chapter 10 will act on the third day much as he acted on the second -that is to say, he will see the policeman at the corner of the street, but will not question him.

When the action is repeated by J for the tenth time, the difference between J's repetition of it and I's will be due solely to the difference between a recollection of nine past performances by J against only eight by I, and this is so much proportionately less than the difference between a recollection of two performances and of only

one, that a less modification of action should be expected. At the same time consciousness concerning an action repeated for the tenth time should be less acute than on the first repetition. Memory, therefore, though tending to disturb similarity of action less and less continually, must always cause some disturbance. At the same time the possession of a memory on the successive repetitions of an action after the first, and, perhaps, the first two or three, during which the recollection may be supposed still imperfect, will tend to ensure uniformity, for it will be one of the elements of sameness in the agents-they both acting by the light of, experience and memory.

During the embryonic stages and in childhood we are almost entirely under the guidance of a practised and powerful memory of circumstances which have been often repeated, not only in detail and piecemeal, but as a whole, and under many slightly varying conditions; thus the performance has become well averaged and matured in its arrangements, so as to meet all ordinary emergencies. We therefore act with great unconsciousness and vary our performances little. Babies are much more alike than persons of middle age.

Up to the average age at which our ancestors have had children during many generations, we are still guided in great measure by memory; but the variations in external circumstances begin to make themselves perceptible in our characters. In middle life we live more and more continually upon the piecing together of details of memory drawn from our personal experience, that is to say, upon the memory of our own antecedents; and this resembles the kind of memory_we hypothetically attached to cream a little time ago. It is not surprising, then, that a son who has inherited his father's tastes and constitution, and who lives much as

his father had done, should make the same mistakes as his father did when he reaches his father's age-we will say of seventy-though he cannot possibly remember his father's having made the mistakes. It were to be wished we could, for then we might know better how to avoid gout, cancer, or what not. And it is to be noticed that the developments of old age are generally things we should be glad enough to avoid if we knew how to do so.

F WE OBSERVED THE RESEMBLANCE BEtween successive generations to be as close as that between distilled water and distilled water through all time, and if we observed that perfect unchangeableness in the action of living beings which we see in what we call chemical and mechanical combinations, we might indeed suspect that memory had as little place among the causes of their action as it can have in anything, and that each repetition, whether of a habit or the practice of art, or of an embryonic process in successive generations, was as original as the Origin Species itself, for all that memory had to do with it. I submit, however, that in the case of the reproductive forms of life we see just so much variety, in spite of uniformity, as is consistent with a repetition involving not only a nearly perfect similarity in the agents and their circumstances, but also the little departure therefrom that is inevitably involved in the supposition that a memory of like presents as well as of like antecedents (as distinguished from a memory of like antecedents only) has played a part in their development-a cyclical memory, if the expression may be pardoned.

There is life infinitely lower and more minute than any which our most powerful microscopes reveal to us, but let us leave this upon one side and begin with the amoeba. Let us suppose that this structureless morsel of protoplasm is, for all its structurelessness, composed of an infinite number of living molecules, each one of them with hopes and fears of its own, and all dwelling together like Tekke Turcomans, of whom we read that they live for plunder only, and that each man of them is entirely independent, acknowledging no constituted authority, but that some among them exercise a tacit and undefined influence over the others. Let us suppose these molecules capable of memory, both in

their capacity as individuals, and as societies, and able to transmit their memories to their descendants, from the traditions of the dimmest past to the experiences of their own lifetime. Some of these societies will remain simple, as having had no history, but to the greater number, unfamiliar, and therefore striking, incidents will from time to time occur, which, when they do not disturb memory so greatly as to kill, will leave their impression upon it. The body or society will remember these incidents, and be modified by them in its conduct, and therefore more or less in its internal arrangements, which will tend inevitably to specialization. This memory of the most striking events of varied lifetimes I maintain, with Professor Hering, to be the differentiating cause, which, accumulated in countless generations, has led up from the amoeba to man. If there had been no such memory, the amoeba of one generation would have exactly resembled the amoeba of the preceding, and a perfect cycle would have been established; the modifying effects of an additional memory in each generation have made the cycle into a spiral, and into a spiral whose eccentricities, in the outset hardly perceptible, are becoming greater and greater with increasing longevity and more complex social and mechanical inventions.

We say that the chicken grows the horny tip to its beak with which it ultimately pecks its way out of its shell, because it remembers having grown it before, and the use it made of it. We say that it made it on the same principles as a man makes a spade or a hammer, that is to say, as the joint result both of desire and experience. When I say experience, I mean experience not only of what will be wanted, but also of the details of all the means that must be taken in order to effect this. Memory, therefore, is supposed to guide the chicken