Page:Popular Science Monthly Volume 53.djvu/819

Rh very early lost a limb, and it has been shown that those brain centers that normally would be active in the management of the muscles of this limb were never developed. In order, then, to the full development of the whole motor area of the brain, there must be a rich and full exercise of the muscular functions of the body. Not merely must each muscle become powerful, but the faculties of co-ordination and control must be developed. These appear to be even more related to the finer organization of the nerve structure than does the exhibition of power. We are accustomed to speak of the hind brain as largely co-ordinating, the mid-brain as largely motor, and the front brain as probably inhibitory. I am inclined to think that investigation will show that not only the hind brain and the mid-brain, but the inhibitory brain as well, are related to muscular control; that the lath toward perfect control, including inhibition, is the path of perfect control of muscle, the inhibitory centers themselves are related to the control of the muscular centers, or the muscles themselves. There are some nerve centers having to do with muscular contraction that ripen without ever having the muscles concerned in active operation. For instance, the respiratory center: the newly born baby finds both his neural and muscular respiratory apparatus in perfect condition for operation. It may be that when a sufficient number of thousands of years have passed, the whole brain will be in the condition that the respiratory and a few of the other brain centers are now. Physical education then will be nil, and we shall look to physical exercise merely as a hygienic measure to insure health, all the neuro-muscular mechanisms ripening and coming into perfect function, through the inherited discipline furnished by countless generations of ancestors. In the present day, however, varied muscular exercise is an absolutely necessary element for the development of the brain, and upon the right development of the brain is dependent the large bulk of our psychical activities.

3. The subject of fatigue must interest all physical trainers. Muscular fatigue, as we usually speak of it, is our consciousness of the partial exhaustion of the motor centers of the muscles that have been worked. It is thought that we do not often experience in ordinary life genuine fatigue of the muscle cell. This is not the only form of fatigue. When certain brain centers are fatigued, we can then turn to other centers, centers concerned with the operation of other muscular groups, and operate them. When these are fatigued we can turn to still others, but, long before there comes the exhaustion of the motor elements for all the muscles, there is another fatigue that supervenes, so that muscles that have not been concerned in the activity can not be operated with either power or accuracy. I do not believe that it can be shown that this is due merely to the