For instance, he had been interested in the maps illustrating the various fronts in the European War, with which the walls of his father's study were hung, and although left entirely by himself he had become intensely excited and exhausted by the eagerness with which he had spent a whole morning, with a wealth of imaginative force, in drawing a map of the garden of his house and converting it into the likeness of a war map, filled with imaginary Army Corps. Such excessive expenditure of nervous force is unusual even in older children, and as in this case is found usually only when there is a pronounced nervous inheritance. In little children in the nursery, solitary play or play between themselves seldom produces nervous exhaustion. It is quite otherwise when the child is dependent to a too great extent upon the participation of adults. It is almost impossible for the mother and nurse not to take the leading part in the exchange of ideas, and no matter what may be their good intentions, the pace set is apt to be too great. Environment, without the intrusion of the adult mind, is best able to adjust the necessary stimulus and produce development without exhaustion. Play with grown-up persons, the reading aloud of story books, the showing of pictures, and so forth, undoubtedly have their own importance, but they should be confined within strict limits and to a definite hour in the daily routine. There is sometimes too great a tendency for parents to make playthings of their little children. Save at stated times, they must curb their desire to join in their games, to gather them in their arms, to hold them on their knee, while they stimulate their minds by a constant succession of new impressions. With an only child, whose existence is the single preoccupation of the nurse and mother, and, often enough, of the father as well, it is difficult to avoid this fault. Yet, if wisdom is not learnt, the damage to the child may be distressingly serious. He rapidly grows incapable of supporting life without this excessive stimulation. Without the constant society and attention of a grown person, he feels himself lost. He cannot be left alone, and yet cannot enjoy the society he craves. He grows more and more restless, dominating the whole situation more and more, constantly plucking at his nurse's skirts, perversely refusing every new sensation that is offered him to still his restlessness for a moment. The result of all this stimulation is mental irritability and exhaustion, which in turn is often the direct cause of refusal of food, dyspepsia, wakefulness, and excessive crying.