PEARSE. — THE REACTIONS OF AMPHIBIANS TO LIGHT. 



183 



TABLE IX. 



Reactions of Six Eyeless Toads to .Vertical and 

 Horizontal Light. 



E. The Effects of Illuminating Small Areas of Skin on 

 Eyeless Toads. 



In order to test the reactions of eyeless toads to local stimulation by 

 light in various regions of the skin, individuals were placed two centi- 

 meters behind a screen containing a circular opening 3.2 millimeters in 

 diameter, through which a horizontal beam of light passed. To render 

 the rays of light as nearly parallel as possible a large condensing lens 



Figure 5. Toad, viewed from right side, 

 regions illuminated. 



The dotted areas indicate the 



was interposed between the screen and the light. A small area of skin 

 could thus be strongly stimulated by light ; the light used had an in- 

 tensity of 474 candle-meters. The three regions shown by the dotted 

 areas in Figure 5 were stimulated, and they may be designated as the 

 regions of the front leg, the hind leg, and the back. Before each of 



