More light may be thrown on the relationship between children and their teacher by a discussion of some types of children that at any rate young teachers find difficult. The atmosphere can be described, rather than defined, as an active and mutual sympathy between the teacher and children. Just as the great artist and the great craftsman learn to understand and use their material, so must a teacher understand children. To get the best out of life in the class, the teacher must know the home conditions of the children. The care of the class-room, the checking of stock, the preparation of material for lessons should be almost entirely the work of the class. Because children have short memories and fluctuating standards, a teacher must oversee and occasionally remind people of their duties. Well-managed children are naturally willing, cheerful and friendly, and these characteristics, that make children delightful to teach, must give the tone to class life.