We cannot perform an act voluntarily unless we know what we are going to do, and we cannot know exactly what we are going to do until we have learned to do it. The very simplest movement brings about a change in the organic structure of the brain, and this change leads to more complex movements and further improvement in brain structure. Most skilled movements give more exercise to the central nervous system than to the muscles. Movements calling for a high degree of skill, correlation of the different senses, sense discrimination, fine coördinations, and a rapid and responsible exercise of judgment, all tend, through the action of the association fibers, to a high degree of brain development. An essential feature of exercise is that a part of it at least shall afford amusement, diversion, and recreation to the overwearied and harassed brain. Hence, the necessity to introduce dancing, field sports, etc. By these means industrial efficiency, communal morality, and social consciousness are promoted. Public amusements of a proper sort are a public necessity. The great menace to the city is the limited opportunities for healthful play, and over one-third of the population of the United States live in towns. The physical side of the question is the largest, for it involves health, and consequently poise and self-control. It involves a legitimate occupation of surplus energy and its wise direction, and it also involves companionship. The great object of physical training is then to secure the most perfect development of the body, with the corresponding development of the brain, so that the highest physical and mental efficiency of the individual may be attained. The possession of a large reserve of muscle and nerve force, ready to be used in any emergency, gives confidence to the individual, increases the spirit of taking the initiative and undertaking grave responsibilities that come into the life of every woman, especially those who are engaged in the business or professional world, and the building up of this necessary reserve force is one of the inestimable advantages of a gymnastic and athletic training. =The Physiology and Pathology of Exercise.=—Exercise is divided into active or voluntary and passive. Passive exercise does not require any exertion of the will power. Massage increases the local nutrition of the parts, stimulates the nerves, and is restful, rather than exhausting, to the overwrought brain and wearied nerves.