576 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



The results are compared directly in figure 105. The performance 

 of each squad is represented by three curves: (1) total number of 

 columns added in 10 minutes; (2) number of columns correctly added 

 in 10 minutes; and (3) percentage of errors in the total number of 

 columns added. In the case of the total number of columns both 

 squads began at identically the same level. Squad A shows a rather 

 smooth and gradual practice curve, with the exception of the points 

 at November 10 and February 2. On the latter date evidently special 

 effort was made. Squad B does not show so much improvement. 

 The second session was slightly below the record of the first, but it 

 must be recalled that the time interval elapsing was 1 month. At 

 January 5 there is a distinct drop. This was apparently caused in 

 largest part by the absence of subject Tho, the champion adder of the 

 squad, who had been a bank clerk. Tho, because of transportation 



Squad A 

 Squad B 



Fig. 105. — Average results in the 10-minute addition test. 



difficulties in returning from the Christmas vacation, was unable to 

 reach the Laboratory on this evening until the group work had been 

 completed. Squad B also reached their highest point on the last date, 

 January 27. The two preceding dates for this squad, January 13 

 and 19, both of which were in the reduced-diet period, were not up to 

 the level that would have been expected on the basis of the performance 

 for December 15 and previously. The whole squad was present on 

 January 13 and 19. One would therefore normally expect some in- 

 crease over previous experiments. The fact that there was none may 

 reasonably be charged to the low-diet conditions. 



