RELATIVE STIMULATING EFFICIENCY OF LIGHT 



157 



TABLES 



Relation between stimulating efficiency and flashes of low frequency. The num- 

 bers indicate the degree of deflection from the line bisecting the angle between'two 

 beams of equal illumination, crossing at right angles. One beam, continuous; 

 the other, intermittent. "Plus," deflection toward source of intermittent light; 

 "minus," deflection toward source of continuous light. This table is the sum- 

 mary of the results obtained in 3400 trials, each number given being the average 

 angle made in 20 trials, except those for butterflies IS and 8, which are the average 

 of 10 trials 





