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JOSEPH U. YARBROUGH 



zer and sometimes rise up and ' sniff ' at it before going into the 

 box." (3) A period of hesitation. The behavior of this period 

 is characterized by wavering and by starts and stops. And, in 

 period (4), the cat gives strict attention to the stimuli. Here 

 the behavior becomes more nearly perfect, the path of reaction 

 has been made straight, and the percentage of correct reaction 

 is high. With the animals tested on light, set A, the same 

 learning period divisions could be made. In this case, however, 

 the period of disturbance was not accompanied by so much 

 timidity and fear. 



During this period of experimentation all possible care was 

 taken to prevent any preference for particular boxes. Should 

 such a tendency be observed, control tests were given to break 

 it up before the position habit was well developed. At the end 

 of the first 60 trials each box had been presented 20 times, and 

 the records show that no box was chosen more than 26, nor 

 less than 16 times by any one of the eight subjects. 



For comparison we bring together in table III data on learn- 

 ing the association obtained by Hunter in his "study of animals 

 and place beside it that of our own subjects. 



It is of interest to note that all the cats fall in the class with 

 Bob, Hunter's most rapid raccoon. Bob learned the association 

 in 120 trials while the eight cats used in these tests ranged from 

 50 to 180 trials with an average of 107 trials each. The curve 

 representing the learning period for the discrimination of the 

 three compartments was very short and steep, yet broken and 

 irregular. With continued practice, this irregularity would un- 

 doubtedly have been eliminated; and the cats of each set would 

 have attained perfect mastery of their problem. 



