344 Journal of Comparative Neurology and Psychology. 



bar about 4 cm. long was fastened. It was 13 cm. from the door 

 and 4 cm. below the top of the cage. A slight pull on the bar 

 caused the door to fly open. Food was placed in front of the door 

 in plain sight. 



After a good deal of trouble No. i was taught to open the door 

 by pulling the bar with his teeth and forepaws. Then the other 

 rats were given opportunity to learn to get out by watching No. i 

 open the door. In every case the untrained rat was fed when he 

 followed No. I out. Then he was put back into the box alone for 

 Ave minutes, his conduct being carefully noted. If he got out in 

 less than the five minutes he was fed and put back again. This 

 was continued until he thoroughly understood how to open the 

 door. But if he did not get out within five minutes, No. i was 

 put in with him again. 



NO. 2 IMITATING NO. i. 



No. I No. 2 follozvs No. 2 



Date gets out A^o. 2 sees No. 1 out gels out Time 



Dec. 2 I o I — — 



— — — I 4' 



Dec. 2767 — — 



Dec. 4111 — — 



Dec. 4 — — — I 2' 



Dec. 4 — — — I i' 



Dec. 4 — — — I 2' 



Dec. 4 S 5 5 — — 



Dec. 5 I I I — — 



Dec. 5 — — — I 5' 



Dec. 5434 — — 



Dec. 6 — — — 1 4' 



Dec. 6 — • — — 1 3' 



Dec. 6 — — — I i' 



Dec. 6 — — — I 15" 



Dec. 6 • — — — I 40" 



Dec. 6 — — — I 10" 



Dec. 6 



30 



Totals 19 16 19 



At first when No. 2 was put in with No. i he paid but little 

 attention to him. But after he had seen No. i open the door a few 



