24 

 additional data 'c::' 1 m. BTith tl 1 3 information, in- 



dividual differences in the ability to learn can be com- 

 pared with their brain weights. As it v/ould be impracti- 

 cable to correlate rats given one, three or five trials 

 together, no special table for correlation was constructed. 

 A table which is attached to the records of learning of 



rats, is probably the most convenient that could be 

 made. 



There still remains to describe the curves represent- 

 ing the progress in the organization or integration of 

 primal movements in learning the problem. These curves 

 are found in Curve II of the latch box. They show simi- 

 lar peculiarities to the curves representing one, three 

 and five trials. One trial is the longest and most ir- 

 regular in the early trials. The next is that of trials 

 every other day ( and the shortest and simplest is that of 

 trials every two days. Again relatively few trials were 

 required of the latter after the rapid descent was made 



