648 



SYLVAN J. KAPLAN 



Fig. 1. The Lashley III Maze. 



Table II reflects the significance of difference between groups and the 

 direction of the differences. The groups identified with capital letters are 

 400-day-old rats, while those labeled in small letters are 90 days old. 



1. No significant differences on any measures were found between the 

 control groups. 



2. The older irradiated groups were found to be significantly inferior to 

 the controls on all measures. 



3. The 150 r/8.5 day and the 50 r/7.5 day younger groups were signifi- 

 cantly inferior to the control groups on all measures. Aside from these find- 

 ings and the fact that the 100 r/8.5 day younger group was inferior in terms 



