202 



H. M. JOHNSON 



variations from the mean of the individual daily averages ac- 

 cording to the number of trials in the individual daily series 

 referred to 20 as a basis. The mean variation of the averages 

 of the daily series from the general average is expressed in units 

 of the latter in tables 4 and 5, and it gives an indication of the 

 consistency and hence the reliability of the results. 



TABLE 4 

 Record of Monkey 2 



Width of individual striae on both fields: 0.780 mm. 

 Mean brightness, both fields: 6.24 candles per sq. meter 

 Striae on positive (standard) field: horizontal 



