WHAT IS INTELLIGENCE? 193 



nervous system there is a neural society in which there 

 are aristocrats who rule and give orders, and servants 

 who serve and obey. Higher centres control but do not 

 domineer over lower. The doctrine of a neural hierarchy 

 is one of the most luminous in modern neurology." 



It is a wonderful thing how the nerve centres take care 



of the different special work here and there in the body, 



many times against our will that is against the cells of 



the brain connected with our senses. Such acts as cough- 



^ ing or sneezing in church we would like to stop, but the 



tickling sensation in the nose or throat brings on the 



5 sneezing or coughing, in spite of our wishes. If it were 



V not so, we would soon get in more serious trouble, when 



p dangerous germs attack the membrane of the throat or 



V nose. 



The nerve cells who have charge of the work of pre- 

 venting dangerous germs entering or getting lodged in 

 the lungs or throat, and in that way finally getting into 

 the blo<id stream and probably destroying the whole 

 ^ body, are continually on the lookout for these dangerous 

 jj enemies, and when they lodge on the membrane of the 

 [y throat or nose, in the act of breathing, they attempt to 

 \ expel them or dislodge them by first secreting and envel- 

 N oping them in a sticky fluid and then blowing them out 

 entangled in the fluid, by the act of sneezing or coughing. 

 There are nerve centres who have charge of secreting the 

 K sticky fluid, and other centres in charge of the very com- 

 plicated, but very effective muscular act of coughing and 

 sneezing. The act of blinking is also a performance at- 

 > tended to without our knowledge or attention. Some- 

 \^ times certain nerve centres will be made active by causes 

 "N^ unknown to us, or by fear, anger, joy, etc., and cause a 

 ' person to act in a different manner. The nerve centres 

 in charge of the heart sometimes by reason of fear or 



