All schemes for fixation lose their virtue through time, but they may be abandoned for other reasons, one of the principal of which is the development of pain. By dint of rubbing or pressing his nose or his chin on the knob of his cane and the back of his chair, O. has produced little excoriations and sores on the parts concerned, the pain of which acts as a deterrent, but his tics and para-tics break out afresh whenever it has gone. The game has been carried to such an extent that under the chin and at the root of the nose there have appeared actual corns--strange stigmata of one's "profession." The details in the mental process are similar to what has been already noted: It was the craving to keep my head in a correct position that induced the habit of leaning my chin on something, and I found it essential to feel the contact; familiarity, however, soon ended in my failing to perceive it, and a new movement was made that I might experience the sensation once more. And so on the ball rolled, till augmentation of the force I exerted, under a constant incitement to feel something more or something else, resulted in the formation of callosities on nose and chin. In this way factitious wants come into being, which may be described as a sort of _parasitic function_ of which the patient is alike the creator and the dupe. O.'s therapeutic ingenuity, however, could not rest satisfied except when some fresh contrivance was being put to the test. Needless to say, at one time he experimented with the stiff collars affected by some sufferers from mental torticollis.