Berry, Imitation in Cats. II 



In the tests of imitation which were now made Z instead ofX 

 was used part of the time to open the door. The behavior of Y 

 was just the same whichever cat was used. The general method 

 was to take X out after she had opened the door once, and let Y 

 try the door alone for five minutes. If he did not get it open X 

 was then put in with him again. However, on the last day of 

 the experiment X was allowed to open the door six times in 

 succession before she was taken out of the box. 



During the first part of the experiment Y imitated X very closely. 

 When X was taken out he frequently tried the trap-door; but dur- 

 ing the latter part of the experiment he only looked on while X 

 opened the door and ate the meat. During the frst series of six 

 trials on the last day Y merely looked on, during the second series 

 he smell ed of the door each time X opened it, and during the third 

 series he reached through the door after X had taken out the meat. 

 After X had been taken out of the box upon the conclusion of the 

 third series of trials Y went to the door and opened it at once. After 

 that he opened the door as fast as I could put in the meat and close it. 



Experiment 6. Rolling Ball into Hole. 



Method. — In Box I a hole large enough to admit a tennis ball 

 was made in the middle of the bottom of the box, 12 cm. from one 

 end. In the middle of the end of the box next to the hole and 

 25 cm. above the floor a small door (6x6 cm.) was placed. This 

 door, which opened inward, w^as held shut by a wooden crossbar. 

 The mechanical devise was of such a nature that when the ball 

 rolled through the hole and fell into a box below, the pressure on the 

 box raised the crossbar and permitted the door to fly open. The 

 opening of the d>oor exposed to view a small piece of meat which 

 the cat easily could reach. In order to make it easier for the cat 

 to roll the ball into the hole a wooden triangle (44 x 44 x 29 cm.) 

 was fastened to the bottom of the box with the hole at its apex 

 (see Fig. i). 



Results.— Btloyv are given the periods during which the cats 

 were given an opportunity to discover that meat could be obtained 

 by rolling the ball into the hole. 



Two or three times the ball was knocked into the hole accident- 

 ally while the kittens were playing together. Strange as it may 

 seem, X was the only one of the kittens that showed any dispo- 

 sition to play with the ball. It is true that occasionally one of the 



