In this view, then, we regard the fragments of perceptive power over which the hysteric has lost control as being by no means really extinguished, but rather as existing immediately beneath the threshold, in the custody, so to say, of a dreamlike or hypnotic stratum of the subliminal self, which has selected them for reasons sometimes explicable as the result of past suggestions, sometimes to us inexplicable. If this be so, we may expect that the same kind of suggestions which originally cut off these perceptions from the main body of perception may stimulate them again to action either below or above the conscious threshold. We have already, indeed, seen reason to suppose that the submerged perceptions are still at work, when Dr. Janet pointed out how rare a thing it was that any accident or injury followed upon hysterical loss of feeling in the limbs. A still more curious illustration is afforded by the condition of the field of vision in a hysteric. It often happens that the field of vision is much reduced, so that the hysteric, when tested with the perimeter, can discern only objects almost directly in front of the eye. But if an object which happens to be particularly exciting to the hypnotic stratum--for instance the hypnotiser's finger, used often as a signal for trance--is advanced into that part of the hysteric's normal visual field of which she has apparently lost all consciousness, there will often be an instant subliminal perception,--shown by the fact that the subject promptly falls into trance. In such cases the action of the submerged perceptions, while provoked by very shallow artifices, continues definitely _subliminal_. The patient _herself_, as we say, does not know why she does not burn her anæsthetic limbs, or why she suddenly falls into a trance while being subjected to optical tests. But it is equally easy to devise experiments which shall call these submerged sensations up again into supraliminal consciousness. A hysteric has lost sensation in one arm: Dr. Janet tells her that there is a caterpillar on that arm, and the reinforcement of attention thus generated brings back the sensibility.