196 



C. F. CURTIS RILEY 



time. Table II indicates the position of the toads with respect 

 to the two colored lights for four sets of observations. 



TABLE II 

 Responses of Young Toads to Colored Lights 



It is seen from the table that out of a total of 48 responses, 36 

 are toward the blue light, 8 are toward the red light, and 4 are 

 indifferent, apparently being no response to either of the col- 

 ored lights. The blue is evidently by far the more effective color 

 with respect to the responses of young toads when stimuli from 

 both red and blue light are impinging upon them. 



The results recorded above are largely in accord with those 

 of Graber (I.e., p. 125) on Bufo vulgaris Laur as indicated in 

 the following quotation (I.e.): 



"Dass auch bei diesen Reactionen wieder in erster Linie die Helligkeits- 

 verhaltnisse ausschlaggebend sind, geht schon aus dem Umstande hervor, 

 dass einerseits Dunkel-Rot, andererseits Dunkel-Blau vorgezogen wird. 

 Speciell aus der ersten Vergleichung, wo Rot sehr bedeutend dunkler 

 als Blau und doch nur wenig starker als letzteres besucht ist, konnte 

 aber vielleicht geschlossen werden, dass diese Farbe als soloche der Krote 

 weniger angenehm als Blau sei. * * * 



Rot 1 

 2) = ?" 



Blau m. uv. 1 . 2 



While it is true that in one series of experiments when " Dunkel- 

 Rot" and "Hell-Blau" lights were employed, the number of 

 responses were 305 toward the former and 288 toward the 

 latter, or in proportion of 1 : 0.9, yet in another series when 

 "Hell-Rot" and "Dunkel-Blau" were used, the responses were 

 108 to 142, or in the reaction-proportion of 1 : 1.3. Graber 

 (I.e., p. 122) experimenting with Rana esculenta L. obtained 

 results somewhat at variance with those of the writer on young 

 toads. The lights employed were "Hell-Rot" and "Dunkel- 

 Blau." Three sets of experiments were performed, each con- 



