reason, and imagination, the emotions, and such acts as 

 walking and working. 



The white matter of the brain contains no cells; it is not 

 a dynamo. No driving force is generated within it. The 

 white matter of the brain is a matrix in which, by electric 

 charge generated within the cells of the gray matter, an 

 infinitely delicate network of conducting pathways of 

 action is laid down, and, with the passage of each electric 

 charge, these molecular paths of conductance, or "action 

 patterns," 1 become facilitated. 



Francis Benedict states that abstract thinking requires 

 little oxidation or metabolism. In a critical study of the 

 effect of mental work on metabolism (oxidation), Benedict 

 measured the rate of oxidation while the subjects performed 

 mental work and found that if there was any change in 

 metabolism, it was slight. 



The respiration, the circulation of the blood, the digestion 

 of food, the work of the kidneys, and the minimum amount 

 of oxidation necessary to maintain the life of the brain 

 cells all these are included in what is called basal metabo- 

 lism. Basal metabolism does not include the oxidation 

 required for walking and running, thinking, hearing and 

 speaking, seeing and smelling. 



The evolution of the brain, from those animals in the life 

 line to civilized man, consisted of an increased specializa- 

 tion involving both the white matter, or thinking brain, 

 and the gray matter, or cortex. In the evolution of the 

 brain from the level of that of wild animals, there were 

 added many new mechanisms, each of which had survival 

 value. The mechanism of balancing upon the hind feet, 

 of walking, bending, kneeling required not only a great 

 increase in the units of the gray matter but also an increase 

 in the units of the white matter. 



No wild or domestic animal possesses so complicated a 



1 CRILE, GEORGE W., "A Bipolar Mechanism of Living Processes," The 

 Macmillan Company, New York, 1926. 



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