THE ASSOCIATIVE PROCESSES IN ANIMALS. 71 



(I) 



SITUATION. 

 Same as (i). 



E. 



IMPULSES. 

 To run to E. 



(2) 



ACTS. 



Corresponding to 

 impulse. 



RESULTING FEELINGS. 



Continuation of sit- 

 uation. 

 Fatigue. 



Pleasure of company. 



" food. 



" " surround- 

 ings. 



RESULTING FEELINGS. 

 Pleasurable as above. 



A graphic representation of the progress from an early trial 

 to a trial after the association has been fully formed is given in 

 the following figures, in which the dotted lines represent the 

 path taken by a turtle in his fifth (Fig. 2) and fiftieth (Fig. 3) 

 experiences in learning the way from A to his nest. The 

 straight lines represent walls of boards. Besides the useless 

 traveling, there were, in the fifth trial, useless stoppings. The 

 time taken to reach the nest in the fifth trial was seven minutes ; 

 in the fiftieth, thirty-five seconds. The figures represent typ- 

 ical early and late trials, chosen from a number of experiments 

 on different individuals in different situations, carried on at 

 Woods Holl by Mr. R. M. Yerkes, of Harvard University, to 

 whom I am indebted for permission to use these figures. 



Now the process of learning here consists of the selection, 

 from among a number, of a certain impulse and act in connec- 

 tion with a certain situation. And our first business is to dis- 

 cover the cause of that selection. The result of such discovery 

 was dogmatically stated in the previous lecture : " Any impulse 

 to an act which, in a given situation, leads to pleasurable feel- 

 ings, tends to be connected more firmly with that situation ; 

 and any impulse to an act which, in a given situation, leads to 

 discomfort, tends to become weakened in connection with that 

 situation." I say tends because the pleasurable feelings must 

 follow the act within certain limits of time must be important 



