Slonaker, Activity of the Rat. 



357 



a rat run continuously but a few minutes. They may be active, 

 however, for hours with only very short periods of rest. 



The curves of the total activity are seen in Fig. 8. For the 

 first twenty days after the experiment started there was little or no 

 variation in the curves and they coincided with the average curve. 

 From this time on individual variation appears. A marked 

 difference is thus seen in the total number of revolutions. It is 



Revolutions 

 140000 



120000 



60000 



40000 _ 



Avg. 



Days 



Fig. 8. Cur\-es representing the total activity of rats from the same Htter as indicated by the number 

 of revolutions of the revolving cages. The average curve is shown in heavy line. ,5 •, 



also noticed that each curve very closely resembles in general 

 appearance the average curve. Whether these curves would 

 finally have approached each other or would have diverged more 

 had the experiment continued can not be predicted. 



The following table (Table V) gives the average daily activity 

 throughout the experiment. The average is computed for each 



