INSTINCTS 



247 



the result of use (exercise) or disuse. It is for this reason that 

 habits acquired in youth are most lasting, and it is for this 

 reason that "you cannot teach an old dog new tricks." Things 

 that "' come natural " to us early in life become difficult if they 

 are not practiced ; tricks that we learn in our youth are for- 

 gotten if not practiced. Thus we may lose instincts and out- 

 grow them ; or we may fix them in our ways of life, remaining 

 childish though old in years. 



