We observe that in later life much less difficult and intricate operations than breathing acquire much longer practice before they can be mastered to the extent of unconscious performance. We observe also that the phenomena attendant on the learning by an infant to breathe are extremely like those attendant upon the repetition of some performance by one who has done it very often before, but who requires just a little prompting to set him off, on getting which, the whole familiar routine presents itself before him, and he repeats his task by rote. Surely then we are justified in suspecting that there must have been more _bonâ fide_ personal recollection and experience, with more effort and failure on the part of the infant itself than meet the eye. It should be noticed, also, that our control over breathing is very limited. We can hold our breath a little, or breathe a little faster for a short time, but we cannot do this for long, and after having gone without air for a certain time we must breath. Seeing and hearing require some practice before their free use is mastered, but not very much. They are so far within our control that we can see more by looking harder, and hear more by listening attentively—but they are beyond our control in so far as that we must see and hear the greater part of what presents itself to us as near, and at the same time unfamiliar, unless we turn away or shut our eyes, or stop our ears by a mechanical process; and when we do this it is a sign that we have already involuntarily seen or heard more than we wished. The familiar, whether sight or sound, very commonly escapes us. Take again the processes of digestion, the action of the heart, and the oxygenisation of the blood—processes of extreme intricacy, done almost entirely unconsciously, and quite beyond the control of our volition. Is it possible that our unconsciousness concerning our own performance of all these processes arises from over-experience? Is there anything in digestion, or the oxygenisation of the blood, different in kind to the rapid unconscious action of a man playing a difficult piece of music on the piano? There may be in degree, but as a man who sits down to play what he well knows, plays on, when once started, almost, as we say, mechanically, so, having eaten his dinner, he digests it as a matter of course, unless it has been in some way unfamiliar to him, or he to it, owing to some derangement or occurrence with which he is unfamiliar, and under which therefore he is at a loss now to comport himself, as a player would be at a loss how to play with gloves on, or with gout in his fingers, or if set to play music upside down. Can we show that all the acquired actions of childhood and after-life, which we now do unconsciously, or without conscious exercise of the will, are familiar acts—acts which we have already done a very great number of times?