THE KINETIC SYSTEM 185 



and whether or not the organs are interdependent in 

 their action. 



Let us assume for the moment that the work con- 

 sists of the conversion of the potential energy stored 

 in the brain cells in the form of chemical compounds 

 - Nissl substance into electricity, or some similar 

 form of transmissible energy, which on its release 

 activates, among other glands and organs, the thyroid 

 and the adrenals, the secretions of which in the form 

 of hormones activate the brain, which in turn activates 

 the muscles to convert carbohydrates into heat and 

 motion. It happens that we have an interesting 

 analogy to the work changes produced in the brains 

 of animals by the conversion of chemical energy into 

 heat and motion in the conversion of stored energy 

 into electricity in the electric fish. In this fish a part 

 of the usual neuro-muscular mechanism is replaced 

 by a specialized structure for storing and discharging 

 electricity. We found that after a rapid and contin- 

 uous discharge of their electric energy in response to 

 excitation, the electric fish were exhausted and that 

 their brain cells showed histologic changes identical 

 with those produced in higher animals by muscular 

 work or by heat production. (Fig. 40.) Electricity is 

 a form of energy, and is, of course, convertible into 

 heat or motion. If the discharge of electricity in 

 the electric fish is attended by work changes in its 

 brain-cells, it is not surprising to find work changes 

 in the brain-cells of other animals, as a result of the 

 conversion of their stored energy into heat or motion. 



We found further that electric fish could not dis- 

 charge their electricity when under anesthesia ; and 



