REACTIONS OF WHIP-TAIL SCORPION TO LIGHT 



263 



Fig. 3 Graphical representation of the amplitudes of the whip-tail scor- 

 pion's reactions under illumination from different directions. A, reactions to 

 light from behind; B, reactions to light from the side; C, reactions to balanced 

 opposed light; D, reactions to light from in front. The circles represent the 

 observation circle of the apparatus, the groups of arrows the direction of the 

 light, the central, heavy arrows the position which the animal occupied when 

 subjected to stimulation. Each of the arrows indicating the path taken by the 

 animals represents the average course and point of emergence for ten trials of 

 one individual. 



in bilateral equilibrium, and its corollary that unilateral interfer- 

 ence with the photoreceptive mechanism will produce an un- 

 balance in the normal reactions proportional to the extent of the 

 interference. Since it is planned to extend these experiments 

 considerably, only a brief summary of them and their bearing 

 on the data of the present paper is given. 



