Again, when children know that it will be their lot to come under the tuition of a certain instructor who occupies a permanent post under state appointment, they work faithfully and usually eliminate any criticising attitude. In fact, long terms of service tend to inhibit the criticisms of both children and parents which sometimes attend teachers who occupy positions but for a short time. The situation conduces to a condition of harmony and cooperative activity. The children instinctively feel the authority of the teacher. They know that he has the support of local and state authorities, and that they will cooperate with him in carrying forward his projects. The teacher, in turn, recognizes his responsibilities in the premises and endeavors to occupy acceptably. Now it is just as true that there are some disadvantages to permanency of positions. Teachers are apt to become non-progressive and in some cases, little more than fixtures. Change of environment stimulates progress and development. Variety in teaching experience broadens the capabilities and increases the usefulness of teachers. In addition, children need the touch and influence of many lives. They receive greater inspiration because of coming in contact with the personality of a large number of teachers. However, too frequent change is wasteful. It dissipates the energy of teachers and breaks the continuity of the work of the children. Where the permanency of positions is absolutely uncertain, the teaching profession is transitory and dwindling. Only a few remain for long time in the work under such conditions. Many efficient school men leave the profession annually because of this discouragement. At present, the feeling appears to be general that permanency in position should be conditioned upon improvement in efficiency. Evidently a recognition of this principle is a basic cause underlying the increase in number of appointments to temporary teaching positions. This procedure affords an excellent opportunity for weeding out the unfit. At the same time it acts as a spur inducing growth and development. Progressive tendencies, along with other qualifications, are regarded necessary to appointment even to temporary posts, and, as implied before, success in such positions is a prerequisite to appointment to permanent ones.