thenics, because the music carries with it a distracting influence that permits the contraction and relaxation of muscles to blend one into the other smoothly and gracefully. The various movements become sinuous instead of jerky, and glide into one another without effort. The music does more. It marks the time; it gives the rhythm for each individual movement and makes it precise. The more complicated the calisthenic exercises the more one approaches the formation of the dance.
To the physician, however, more serious questions arise, questions which involve more than muscular development, grace, and precision of movement. I refer to the nervous mechanism which lies behind and causes these outward manifestations. Foremost is the power of mutual adjustment, or co-ordination. As in all other matters, this power is most appreciated when it is impaired or lost. Then one realizes its importance and understands the blight caused by an inability to carry out apparently simple acts of motion and locomotion. The individual muscles act in accordance with the will, but the concerted action fails.
In recent years much progress has been made in restoring lost power of control and adjustment by
elaborate systems of re-education of the muscles.
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