126 



Journal of Comparative Neurology and Psychology 



RESULTS OF EXPERIMENTS. 

 1. Electric Stimulation and Light. 



The following specimen records leave no room for doubt 

 as to the inhibitory influence of increase in light intensity on 

 the electric reaction. In these tests the visual stimulus was 

 given from i to 2 seconds before the electric by the turning on 

 of a i6-candle power electric light which was placed 30 cm. in 

 front of the animal in one series, and 15 cm. above it in another. 



The laboratory records appended are self-explanatory. 



TABLE I. 



Title of iuvestigatioa. . . . Electric- Visual Series (Red Light). 

 Experinieuted on. . . . Green Frog No. 4. 

 Harvard Psychological Laboratory. . . 9.15 A. M., Feb. 28, 1902. 

 Chrouoscope control average 189 (?'. . . Electric stimulus, i Cell. 

 Red light, 16 c. p., 2 seconds before and until electric stimulation. 



Number of Experiment. 



14 

 15 



16 



17 

 18 



19 

 20 



Reaction-time. 

 1445 ' 



192 



5S7 



No reaction. 



No reaction. 



Reaction to second stim. 



No reaction. 



No reaction. 



177 



No reaction. 

 No reaction. 

 No reaction. 

 No reaction. 

 1 1 90 



No reaction. 

 No reaction. 

 No reaction. 

 No reaction. 

 No reaction. 

 No reaction. 



espouse to a i cell electric 



Table I indicates the lack of n 

 stimulus when accompanied by an increase in light intensity, 

 and Table II proves conclusively that the light is the cause of 

 the inhibition of reaction. 



All reaction-times are given in thousandths of a second, indicated by 6. 



