Hirschsprung, as well as Freud, believes that this is often the case as regards finger-sucking and toe-sucking in infancy. Even stroking the chin, remarks Debreyne, may produce a pollution.[220] Taylor refers to the case of a young woman of 22, who was liable to attacks of choreic movements of the hands which would terminate in alternately pressing the middle finger on the tip of the nose and the tragus of the ear, when a "far-away, pleased expression" would appear on her face; she thus produced sexual excitement and satisfaction. She had no idea of wrong-doing and was surprised and ashamed when she realized the nature of her act.[221] Most of the foregoing examples of auto-erotism, are commonly included, by no means correctly, under the heading of "masturbation." There are, however, a vast number of people, possessing strong sexual emotions and living a solitary life, who experience, sometimes by instinct and sometimes on moral grounds, a strong repugnance for these manifestations of auto-erotism. As one highly intelligent lady writes: "I have sometimes wondered whether I could produce it (complete sexual excitement) mechanically, but I have a curious unreasonable repugnance to trying the experiment. It would materialize it too much." The same repugnance may be traced in the tendency to avoid, so far as possible, the use of the hands. It is quite common to find this instinctive unreasoning repugnance among women, a healthy repugnance, not founded on any moral ground. In men the same repugnance exists, more often combined with, or replaced by, a very strong moral and æsthetic objection to such practices. But the presence of such a repugnance, however invincible, is very far from carrying us outside the auto-erotic field. The production of the sexual orgasm is not necessarily dependent on any external contact or voluntary mechanical cause.