272 



The Dancing Mouse 



of my tests with other individuals of the same line of de- 

 scent as those which perished, and I have to regret only the 

 loss of time and labor. 



As I have on hand results for ten individuals of the age of 

 one month, and for four individuals of the age of four 

 months, it has seemed desirable to state the problem, method, 

 and incomplete results of this study of the relation of modi- 

 fiability to age. The indices of modifiability for these two 

 groups of dancers differ so strikingly that I feel justified in 



TABLE 52 

 PLASTICITY (RELATION OF MODIFIABILITY TO AGE) 



Number of Errors in Successive Daily Series of Ten White-Black 

 Tests, with Dancers Four Months Old 



