142 



L. B. NICE 



TABLE 10 



Total ivork in revolutions done by the caffeine mice 



1 No. 14 died at the end of the thirty-second week. 



One mouse in the caffeine line showed great activity and three were much less 

 active. Nos. 13, 15 and 16 ran 1 121 476, 1 366 838 and 2 498 108 revolutions during 

 the course of the experiment. No. 14 ran 1 317 612 revolutions to its thirty- 

 second week when it died. No. 13's record was 49 per cent of No. 16. No. 15 was 

 55 per cent and No. 14 was 60 per cent of No. 16 at the thirty-second week. 



