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K. S. LASHLEY AND S. I. FRANZ 



learned to find food by himself and had to be fed, chiefly with 

 milk given from a pipette. 



Training. He was fed five or six times a day by placing the 

 end of a pipette between his teeth and squirting milk into his 

 mouth. He almost immediately began to reach for the pipette 

 as soon as it was brought in contact with his short vibrissae. 

 An attempt was made to train him to inhibit this reaction. He 

 was first given a taste of milk, the pipette was then wiped off 

 and brought in contact with his short vibrissae. He took hold 

 of it but, getting no milk, let go immediately. This was re- 

 peated every five seconds for fifty-five times with the following 

 results. He reacted every time in the first five trials, four 



5 25 50 75 100 



FIG. 12. RATE OF LEARNING TO REJECT EMPTY PIPETTE 



The number of times that the pipette was taken in successive groups of five 

 trials is plotted. 



times in the second five, once in the third, and not once 

 in the fourth and fifth. After a 60 second interval ten more 

 trials were made. He reached for the pipette the first time but 

 not again. After another 60 second interval he reached once 

 again, then failed to reach for nine trials; so after a third interval. 

 After the fourth interval of 60 seconds he did not reach once in 

 ten trials. Milk was then placed in his mouth twice, the pipette 

 was wiped and offered again. It was grasped five times in the 

 first five trials, once in the second five, and not thereafter. Milk 

 was given again and after this he reached for the pipette four 

 times in the first five trials, four times in the second, and not in 

 the third and fourth. Quite similar results were obtained on 

 the following day. The complete series is given in figure 12. 



