252 ELEMENTARY BIOLOGY 



We make use of the fact that animals form habits in many ways 

 not only in the training of animals for performing tricks for our 

 entertainment but in the everyday work of the farm or the stable. 

 By regular programs in feeding and milking cows, for example, we 

 give them the habit of coming in from the pasture when they are 

 wanted, either at sunset or when we call them ; this saves the work 

 of going after them. Horses learn to follow fixed routes, and they 

 learn to come home after they have strayed away. Chickens come in 

 response to a familiar call, and everybody can tell a good cat or dog 

 story to show how convenient it is for us that they do acquire habits. 



305. Remaining young. As we grow older our protoplasm loses 

 the power to form new extensions and new connections readily. But 

 some people retain the power to form new habits much longer than 

 others. A part of this difference seems to be due to the fact that 

 some people retain their youth, so to speak, by constantly giving 

 their attention to the learning of new ideas, and of doing things in 

 new ways. It may be worth while to establish the habit of changing 

 old habits, or of trying to get new habits as we grow older. 



