Yfrkks, MoclifahiUlv of BeJiavior. 265 



largvly iipoii kiiucstlictic seiisi' data lliau ui>(>ii vision (»r any f»ther 

 special sense, it might serve well to reveal age differences in asso- 

 ciative ability. In this connection we may ask, therefore, Do old 

 dancers learn la1\vrinth i)aths more readily than yonng ones? 



VI. RELATION OF AGE TO RAriDITY OF ACQUISITION OF 

 LABYRINTH HABITS. 



For the labyrinth experiments I selected two mazes which 

 I had i^reviously used for the study of educability in the dancer: 

 they are desiginited as P and C in my Ix^ok.'^ Y) is what I have 

 described as the regular type of maze, and C as the irregular. 

 Training in labyrinth D was given first to each of ten dancers of 

 from one to two months of age, and likewise to the same number 

 of about ten months of age. About a month after the completion 

 of the training in labyrinth D, the same individuals were trained 

 in labyrinth C. 



In all cases the experiments were conducted as follows. Two 

 mice, a male and a female from the same cage, were placed in the 

 nest box of the labyrinth together. One at a time they were given 

 first a preliminary test in which they were permitted to find their 

 way from the entrance to the exit of the labyrinth without being 

 disturbed, and then training tests in which they received a slight 

 electric shock each time they made_ an error in the choice of a 

 path. The tests were continued without interruption, first one 

 individual then the other being tested, until each had perfectly 

 learned the path. \ habit was considered as perfect when an 

 individual succeeded in traversing the maze twice in succession 

 without a mistake. Records were kept of the number of errors in 

 choice of a path and of the time consumed in finding the way from 

 entrance to exit. 



As tyj)ical series of results I present in Table 14 the time and 

 error records in labyrinth D of No. 416, a six-week dancer, and No. 

 166, a nine-month individual. The young mouse was slower than 

 the old one in most of the tests, but he acquired a perfect habit 



"The Daiiciu.ii Mouse, pp. 210. 222. 



