PSYCHICAL ASPECTS OF MUSCULAR EXERCISE. 795 



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 develop- 

 ment 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-ordina- 

 tion 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 investiga- 

 tion 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 

 l^ath toward perfect control, including inhibition, is the path of per- 

 fect 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 opera- 

 tion. For instance, the respiratory center: the newly born baby finds 

 both his neural and muscular respiratory apparatus in perfect condi- 

 tion for operation. It may be that when a sufficient number of thou- 

 sands of yeai"s 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 ordi- 

 nary 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 pres- 



