After acquiring as great a walking speed as is consistent with a graceful and easy carriage, the running exercise should be begun, gradually increasing the distance, but not the rate of speed. In exercising, all tight clothing about the neck, chest, and waist must be removed. Pure air and full breathing are required during and after exercise. Full breathing not only promotes the change of air in the lungs, but also quickens the functions of the circulation and digestion. Eating must be avoided shortly before or shortly after any considerable exercise, as it impairs digestion. Running.-- Running is the best exercise for developing the breathing capacity. While brisk walking is allowable, fast running is not. The rule for running is to begin slowly, run moderately for perhaps fifty feet, then increase the speed gradually; but in running for exercise, never speed to the utmost. A five-mile gait is quite sufficient. The run should be closed with the same moderation with which it was begun, and the girl should never stop short, as this sudden arrest of action gives a most undesirable shock to the heart. In beginning to take any form of exercise the intensity and duration of the movements practiced must be increased very gradually, or positive harm instead of good will be done. As soon as fatigue is appreciable, the exercise should be discontinued and at once be followed by complete rest. Rapid respiration, palpitation or dizziness, headache, the face becoming pale or pinched or flushing suddenly, a feeling of great heat or excessive perspiration, are all danger signals showing that the exercise has already been carried too far and should cease at once. Continued over-exertion carried to a point of exhaustion leads to an obstinate irritability of the heart as well as to organic lesions. Mountain-climbing, rowing, and bicycling call into play almost all the muscles of the body. Of all the outdoor exercises for girls, swimming is one of the most perfect. It not only calls into vigorous action most of the muscles of the body, but spares many of those muscles that are so commonly overworked, the most of the work being performed by muscles that are so little used as to have become flabby and weak. Swimming and sea-bathing must be avoided by girls who have weak hearts and in whom the reaction after a plunge into cold water is never established; also by girls with heart disease or kidney disease. The principal outdoor games are croquet, archery, golf, tennis, cricket, foot-ball, and base-ball. Of these, croquet is the mildest, and is for that reason a good beginning exercise. Croquet, archery, golf, and tennis are all defective in that they cause a greater development of the right than of the left side of the body. As the greater majority of these outdoor exercises can only be indulged in for seven months of the year, they should be supplemented by exercises in the gymnasium for the remaining five winter months.