Nevertheless the brain is there, and Eliza is crossing the ice. The brain sees her. How? Through its receiving neurones. A soldier out in No Man’s Land holds a camera (the eye) in his hand, or dendrite, and takes her picture, which he transfers to his other hand, or axone, ready to pass on. It is like one of these very modern pictures sent by telegraph, for all he receives or passes on is a series of shocks, or “waves of chemical decomposition.” The effect would be the same if the soldiers communicated by means of hand-clasps, a Morse code of squeezes or taps,--something like that. The second soldier (association neurone) having possessed himself of the picture, relays it in turn to the third--one who is in touch with the guns, which in this case are the muscles and glands. The truth, of course, is not quite so simple as this. There are probably nine billion neurones to begin with, each supplied with numerous arms. Any association neurone appears to be able to get in touch with every other neurone in either of the other two classes, and even the simplest picture or bit of information must manifest itself in an unconscionable number of waves or impulses, each one quite meaningless in itself. What a wild tumult of activity must be taking place within us when the battle outside waxes hot! Nor are all the observation posts outside. Many are within the body. And from the data which they all transmit emotions and coördinate actions are born--at least so behaviorists would have us believe. The striped muscles twitch, and bones are jerked about. The unstriped muscles are stimulated to action, and the viscera are affected. The ductless glands increase their secretions, or suspend them. This, say the behaviorists, is what makes us brave; or cowardly; wild with rage or tender with love. Our bowels of compassion are moved. Perhaps we have no stomach for a fight. If we run away the vulgar will declare that we have no guts. But we cannot always be thinking of neurones individually, so we think of them in chains. When two get in touch with each other (through the axone of the one and the dendrite of the other) the connection is called a synapse. When the chain includes all three sorts of neurones, it is called a reflex arc.