To a physician in a Western city there was brought a boy, nine years old, with a face so flat, expressionless, and frog-like, that persons who knew him thought he was feeble-minded. His school teacher reported that his mind seemed a blank and that he was also hard of hearing. His parents complained that he was selfish and sullen. The boy seemed doomed to a life of misery. But, making a physical examination of him, the doctor found reason to think otherwise. He discovered no real brain defect. In the cavity back of the boy's nose he found an abnormal growth of adenoid-tissue that of itself might account for the boy's stupidity and sulky disposition, as well as for his deafness. The diseased tissue acted as an irritant and a drag on his nervous energy; and, in addition, by interfering with the intake of oxygen it lowered the nutrition of the brain. The adenoid growth was removed. Gradually the appearance of the unfortunate boy's face changed for the better. His hearing improved. He began to take an interest in school work, and studied to real advantage. Consideration for others took the place of his habitual selfishness, and he sulked no more. Adenoids, dullness, deafness, and sullenness often are intimately associated. The parents of a sulky child will therefore do well to ascertain whether adenoid trouble is present. Its presence is usually plainly indicated by the flat, insipid appearance of the victim's face and by his habit of breathing through his mouth, particularly when asleep. If there is any reason to suspect adenoids, parents should take their children to a competent physician without delay. Further, and on general principles, they should have their children's teeth thoroughly examined by a good dentist. A child whose teeth are decayed is a child suffering both from nerve irritation and from some degree of poisoning, due to his swallowing food that has become infected by its contact with the germs of dental caries. Such a child has abundant reason to feel uncomfortable, pessimistic, and sullen. So has a child whose teeth, if not decayed, are crowded together. Yet another common, and often unsuspected, physical cause of sulkiness in children is eye-strain. Most of us are under the impression that when a person is afflicted with eye-strain he is certain to have painful or, at least, unpleasant sensations in his eyes. This is by no means always the case. During childhood and youth there may be no telltale eye symptoms at all. But defective eyesight may give rise to various nervous conditions; sulkiness is one manifestation.