in hand, are just as possible as habits of neatness. The laws of habit formation apply in the field of attention just as truly as in every other field of mental life. Laboratory experiments prove the large influence which training has on concentration and the great improvement that can be made. It is true that few people do show much concentration of attention when they wish. This is true of adults as well as of children. They have formed habits of working at half speed, with little concentration and no real absorption in the topic. This method of work is both wasteful of time and energy and injurious to the mental stability and development of the individual. Half-speed work due to lack of concentration often means that a student will stay with a topic and fuss over it for hours instead of working hard and then dropping it. Teachers often do this sort of thing with their school work. Not only are the results less satisfactory, because the individual never gets deeply enough into the topic to really get what is there, but the effect on him is bad. It is like "constant dripping wears away the stone." Children must be taught to "work when they work and play when they play," if they are to have habits of concentration as adults. The length of time which it is possible to attend to the same object or idea may be reckoned in seconds. It is impossible to hold the attention on an object for any appreciable length of time. In order to hold the attention the object must change. The simple experiment of trying to pay attention to a blot of ink or the idea of bravery proves that change is necessary if the attention is not to wander. What happens is that either the attention goes to something else, or that you begin thinking about the thing in question. Of course, the minute you begin thinking, new associations, images, memories, come flocking in, and the attention occupies itself with each in turn. All may concern the idea with which you started out, but the very fact that these have been added to the mental content of the instant makes the percept of ink blot or the concept of bravery different from the bare thing with which the attention began. If this change and fluctuation of the mental state does not take place, the attention flits to something else. The length of time that the attention may be engaged with a topic will depend, then, upon the number of associations connected with it. The more one knows about a topic, the longer he can attend to it. If it is a new topic, the more suggestive it is in calling up past experience or in offering incentive for experiment or application, the longer can attention stay with it. Such a topic is usually called "interesting," but upon analysis it seems that this means that for one of the above reasons it develops or changes and therefore holds the attention. This duration of attention will vary in length from a few seconds to hours. The child who is given