312 Journal of Comparative Neurology and Psychology. 



younc^ guinea pig. The apparatus used was a wire box (6 by 

 6 in.). The apparatus was placed in the experimental cage (de- 

 scribed under Text-fig. i), so that there was nev^er any crowding 

 or cramped quarters for the animals. In many of the experi- 

 ments where the path chosen was of importance, and direction 

 of turning and number of random movements were to be ob- 

 served, the floor of the experimental cage was covered with 

 glazed paper which had been smoked some days before. Pre- 

 liminary experiments showed that the guinea pig was in no way 

 disturbed by any contact, noise or odor of the paper, and never 

 observed it any more than the usual floor of the cage. 



A guinea pig, age i day, was placed at A within the wire 

 box which had a swinging door, x. The larger box had two 

 simple openings at j' and z. The mother was placed outside in 

 the experimental cage. The wires and experimental cage had 

 been carefully freed from all odors by scalding. It will be re- 

 membered that at the age of one day spontaneous movement is 

 very slight, and though the smoked paper shows some move- 

 ment within A, the guinea pig did not find its way out. It 

 saw its mother for it usually faced her as she wandered about 

 the cage. 



Age, 2 days. Conditions and apparatus the same. Ran- 

 dom movements were directed toward finding a way out, and 

 the first solution of the problem was made in i 2 minutes. 



It was replaced. For .25 min. it sat perfectly still with 

 back to the opening and to the mother. Then it turned, and 

 in .083 min. had found her. This is the first proof of the for- 

 mation of an association. 



Upon being replaced for the third time, it found the first 

 opening, but the mother had moved and it went directly toward 

 her. Finding the wire in the way, it went to the second open- 

 ing, y, as usual. Time, .75 min. Few random movements 

 here occurred. 



Test II!. Alteration in habit. 

 The experiment was then modified, and the swinging door 

 turned from the opening. 



[20] 



