324 CELL INTELLIGENCE THE CAUSE OF EVOLUTION 



nerve cells to report what is taking place in their own 

 special world. 



"The brain cell in its dark chamber can receive dis- 

 patches from them alone. If a man loses his sight, the 

 optic nerve brings in no further news and the case is 

 similar to that of the distant city whose telegraphic com- 

 munications have been broken by an earthquake or other- 

 wise. 



"The nerve cells traverse every region of the body, just 

 as telegraph wires thread a continent. Without some 

 such method of transmission, the sensations of sight, 

 hearing, touch and other special senses could as we have 

 seen never reach the brain, neither could commands, such 

 as to move the muscles, be sent out from it. 



"There are nerves which regulate the size of the blood 

 vessels and the nourishment of the body, control the 

 secretions and perform various other offices connected 

 with transmitting stimuli, which are neither sensory or 

 motor. 



"A ganglion is an aggregation or group of nerve cells. 

 Each ganglion is in some respect a little brain. The 

 spinal ganglia receives a sensory impulse and sends out 

 a motor dispatch without calling on the brain. The spinal 

 cord is largely made up of nervous ganglia, sometimes 

 called the little brain. 



"If one were to prick the toe of a sleeper, the sensory 

 nerve at that point would report the fact to one of the 

 lower masses of nerve cells or ganglia, without waiting 

 to hear from the brain ; it would issue a command to the 

 motor nerve cells and the foot would be immediately 

 withdrawn. Unless the thrust was severe, the sleeper 

 would not awaken, nor would he be conscious of pain or 

 the movements of the foot. 



"Thus the cells of the brain are not only saved the 



