1 78 MAN, THE ANIMAL 



has to do with the utilization of energy in order to 

 keep the nerve cells going. Somewhere there 

 must be a portion of a neuron devoted to meta- 

 bolism and as a nucleus is always necessary for 

 these complicated energy changes, scientists have 

 held steadily to the view that the cell body of the 

 neuron is mainly concerned with nutritive re- 

 actions. This leaves the synapse as the essen- 

 tially new relation introduced between these bio- 

 logical units, the neurons. Critical experiments 

 demonstrate that the synapse is more easily 

 fatigued than any other part of the neuron and 

 also that it Is more susceptible to drugs and 

 poisons. 



These structures and relations are all that one 

 can find in the nervous system. They are ar- 

 ranged with infinite complexity and grouped into 

 numerous minute and large pathways. Each of 

 the two functional sensory systems in the nervous 

 system, the somatic sensory and visceral sensory, 

 occupy specific places in the cord and brain and 

 deliver the benefits of their information over to 

 either the somatic motor or visceral motor as the 

 need of the organism requires. This usually re- 

 sults In some form of movement In the body. 



Movement seems to be a strange device to rely 

 upon for all of our information about the mental 

 life of animals yet there is nothing else in the 

 final analysis. Man speaks, writes, runs, waves 



