EFFECTS OF PRENATAL RADIATION UPON LEARNING 



651 



I 90 day old rot 

 '"~;x1 400 doy old re 



Group 

 Rodidtlon 

 Doy of R- 



10 25 50 50 100 150 200 

 8 5 8 5 7 5 8 5 8 5 8 5 II 



Fig. 2. Mean trials, errors, and time to criterion of mastery. 



