INTELLIGENCE OF THE CELL 229 



One writer describes the actions of the mental machin- 

 ery of man, in the following language : 



"The physiologist, as a physicist, observes how a beam 

 of light, a wave of sound, or a vibration of heat affects the 

 organs of sensation ; how they enter the nerves, are trans- 

 formed into an irritation of the nerve-fibers and conducted 

 to the brain cells. Here he loses all trace of them. 



"On the other hand, he observes a spoken word coming 

 from the mouth of a speaking person ; he sees the person 

 move his limbs, and finds these movements are caused 

 by muscular contractions produced through motor nerves 

 irritated by the nerve-cells of the central organs. Here 

 again he is at his wit's end. The bridge which should 

 lead him from the irritated sensory nerve to the irritated 

 motor nerve, is indicated in the labyrinthian connections 

 of the nerve-cells, but he lacks a clue to the infinitely 

 involved processes which are interposed in this place." 



Now the actions of any submarine would seem just as 

 mysterious if we did not realize the fact that the in- 

 dividual itself, which we call submarine, was in charge of 

 intelligent beings, which are directing its actions and 

 course according to the information that it receives from 

 the outside world. 



Just think of the busy life inside of the animal or 

 human individual. The heart and circulating system 

 causes a continuous supply of nourishment and oxygen 

 to every individual cell. It is the cells in the animal that 

 must have oxygen and food, not the animal. In the same 

 way with the submarine, it is the people that occupy it 

 and run it that must have the food and air. Think of the 

 thousands of orders, going to the storage tank we call 

 the stomach, for material to repair this and that. Think 

 of the millions of chemists, one making gastric juice, one 

 bile, one saliva, one tears, one this and one that. Think of 



