Now extend this momentary automatism a little further. We come then to what is called the faculty of improvisation. How much is meant by this term? Is the extempore oration, "the unpremeditated lay," in truth a subliminal product? or have we to do merely with the rapid exercise of ordinary powers? In the first place, it is clear that much of what is called improvisation is a matter of memory. The so-called secondary automatism which enables the pianist to play a known piece without conscious attention passes easily into improvisations which the player himself may genuinely accept as original; but which really consist of remembered fragments united by conventional links of connection. Thus also the orator, "thinking on his legs," trusts himself at first to the automatic repetition of a few stock phrases, but gradually finds that long periods flow unforeseen and unremembered from his tongue. We thus get beyond the range of stereotyped synergies, of habituations of particular groups of nerve-centres to common action. There is some adaptability and invention; some new paths are traversed; adjustments are made for which no mere recurrence to old precedents will suffice. The problem here resembles that well-known difficulty of explaining what goes on during the restoration or "substitution" of function after an injury to the brain. In that case, the brain-elements which remain uninjured slowly assume functions which they apparently never exercised before,--rearranging paths of cerebral communication in order to get the old efficiency out of the damaged and diminished brain-material. This recovery is not rapid like an extemporisation, but gradual, like a healing or re-growth, and it therefore does not suggest an intelligent control so much as a physiological process, like the re-budding on a certain pre-ordained pattern of the severed claw of a crab. Of course this restoration of brain-functions is inexplicable, as all growth is at present inexplicable. We may call it indeed with some reason the highest process of human growth. So viewed, it forms a kind of middle term between ordinary growth of bone or muscle, always on a predetermined plan, and that sudden creation of new cerebral connections or pathways which is implied in an inspiration of genius. Such a juxtaposition need not weaken my claim that the inspirations of genius represent a co-operant stream of submerged mentation, fully as developed in its own way as the mentation of which we are conscious above the threshold. The nature and degree of subliminal faculty must of course be judged by its highest manifestations. And this analogy between the hidden operations of _genius_ and of _growth_ would rather support me in regarding organic growth also as controlled by something of intelligence or memory, which under fitting conditions--as in the hypnotic trance--may be induced to co-operate with the waking will.