188 PROCEEDINGS OF THE AMERICAN ACADEMY. 



TABLE XIII. 



Average Reaction Times in Minutes of Toads previously 

 in the Light or in the Dark. 



(a) Normal Individuals. 



For the experiments with animals in normal condition, Rana 

 palustris was used. Six individuals were successively tested with the 

 colors in the following order, blue, green, yellow, red, and then this 



Figure 6. Plan of apparatus for testing the reactions of toads to colored 

 lights. A, position of observer; a, heat and color screen; b, screen 25 cm. 

 high ; I, light ; s, s, s, s, screen extending to ceiling ; t, t, t, t, table. 



