184 CELL INTELLIGENCE THE CAUSE OF EVOLUTION 



combined acts or intelligence of the entire community, 

 which we call the individual or animal. 



Now we shall take up some of the different and special 

 work taken care of by special committees or nerve cen- 

 ters who have been assigned to look after it, such as 

 breathing, circulation, digestion, etc. Prof. Harris, after 

 describing the brain, makes this statement : 



"Here are situated many of the most important nerve- 

 centers, or collections of nerve-cells, superintending such 

 bodily activities as breathing, the heart's action, the regu- 

 lation of the size of the blood-vessels, perspiration, the 

 flow of saliva, the flow of gastric juice, the chewing of 

 food, swallowing, voice-production, and the act of vomit- 

 ing; and there are other centers still. 



"In a later chapter we shall discover what a center is 

 and what it does. Higher up the brain stem are centers 

 for facial expression, eye movement, iris (pupil) move- 

 ments, focussing of near objects and the secretion of 

 tears. In the brain proper cerebral cortex are centres or 

 areas underlying such states of consciousness as sensa- 

 tion, perception, memory, and emotion, besides speech 

 and voluntary movement." 



This is a plain statement of the facts, how collections 

 of cells have been placed in charge here and there all 

 through the body to superintend this and that particular 

 work. These cells or collections of nerve cells are called 

 little brain or nerve centres. We have the same condi- 

 tions of affairs in other large organizations of individuals, 

 such as a battleship, German army or telegraph system. 



The spinal cord is comprised of a great number of such 

 nerve centres. Prof. Harris states : "The spinal cord is, 

 however, something more than a conductor or transmitter 

 of impulses ; it is also a collection of centres in series from 

 above downwards. Nerves enter the cord and nerves 



