It is a very serious matter when we have superadded to a deficient chest development a deficient chest expansion. For these are the very women in whom because of their general run-down condition and undeveloped muscles the breathing is very superficial; the apices of the lungs, the favorite site of tuberculosis, and the deeper portions are seldom expanded; and not only does the body suffer from a deficient oxygen supply, but there is an equally defective suction power on the part of the heart, which means a poor circulation and a lowered general nutrition of the whole body. The main function in metabolism is oxidation, and scarcely a step in the series of chemical changes proceeding within the body is possible in the absence of an abundant supply of oxygen, constantly renewed. Living in close rooms lowers the vitality to an extent little dreamed of by most persons. _II. The Effect on the Abdominal Viscera._—In the normal erect position the abdominal muscles remain taut and afford proper support and pressure to the abdominal viscera and the great splanchnic circulation of large blood-vessels; whereas in the stooped position the muscles of the abdomen, not being properly used, become weakened and sag forward, causing the downward displacement of all of the abdominal viscera, with consequent disturbance of their circulation and function. Many cases of indigestion, congestion of the liver, and constipation can be explained in this way. _III. The Effect on the Circulation of the Spinal Cord._—The circulation of the spinal cord is very largely dependent on the tone of the muscles of the spine; hence the weakness of these muscles interferes with its circulation. In the spinal cord are large nerve-centers which have to do with the control of the arms and legs as well as of the organs of the trunk, so that anything which lowers the tone of these centers depresses the vitality of the organs supplied by them; and this is believed to be the cause of many cases of so-called nervous indigestion. _IV. The Waste of Energy which Results from Faulty Posture._—Weak foot, in its final stage flat-foot, is more common in women than in men because it is not purely a local condition in the arch of the foot, but primarily due to a weakened condition of the leg muscles that support the arch. Weak feet are gradually converted into flat-feet by faulty standing and walking and lack of leg exercises. Many cases of nervous prostration are to be traced not merely to overwork or worry, but to the waste of energy which results from the faulty posture of the body and with the interference of the circulation in the spinal cord, and the consequent weakness of the nerve power which results. In other words, it is not the load which breaks the bearer down, but the way in which the load is carried.