INSTINCTIVE, EMOTIONAL AND REFLEX ACTION 32$ 



trouble of attending to every little movement, but much 

 time is gained. 



"After the child has learned the difficult art of balanc- 

 ing himself on his feet, walking is largely attended to by 

 other nerve cells than the brain. 



"If acid is placed on the side of a decapitated frog the 

 animal will bring its foot to the spot and try to brush 

 the drop away. Man also has this power after death. 



"The pectoral muscle of a beheaded French criminal 

 was pinched and the right hand was raised to the spot, 

 as if to remove the cause of the injury. 



"The medulla oblongata at the upper end of the spinal 

 cord has more or less control of the sympathetic nervous 

 system, which regulates the heart, lungs, blood vessels 

 and various abdominal organs. If the muscular action of 

 the heart were under direct mental supervision, a person 

 might become so interested in something or so excited by 

 an accident or unusual event that he would forget, until 

 it was too late, to move the muscles of the heart. The 

 same would also be true in respiration. The medulla has 

 power to attend to these, without calling on the brain 

 and obtruding the unnecessary details on consciousness. 



"The brain, like a large city, has much of its complex 

 business systematized and localized. The senses report 

 to certain parts of the brain, while other well denned 

 parts send out a motor order to raise a hand or speak a 

 word. 



The motor zone, or that part of the brain concerned in 

 sending out orders to move the body, lies on either side 

 of the fissure of Rolando. So definitely has this area 

 been mapped out that it is possible to find for the purpose 

 of a surgical operation so small a center as that which 

 moves a vocal cord, directs a thumb or winks an eye, 



"Sensory brain tracts are those concerned in receiving 



