130 



L. B. NICE 



TABLE 2 



Number of revolutions per week of the mice in the control line 



No. 3 was the least active of all the controls. It reached its 

 maximum of 100 003 at the twelfth week and decreased steadily 

 to the end of the experiment. Its minimum run was 36 155 revo- 

 lutions at the thirty-third week. Its average weekly run was 

 63 770 revolutions. 



No. 4 was the most active of the control ixdce. It showed high 

 activity from the tenth to the thirteenth week, from the seven- 

 teenth to the twenty-third week, from the twenty-fifth to the 

 twenty-eighth week and finally at the thirty-second week. Its 



