REACTIONS TO LIGHT IN VANESSA ANTIOPA 



393 



orient if both eyes were stimulated equally. Were this hypothe- 

 sis true, the animal with only one eye functional could not orient, 



Fig. 12 Reproduction of trails made by three butterflies showing reorienta- 

 tion. Large arrows, A and B, direction of rays of light in the two positions of 

 the glower; small arrows, direction of movement of the butterflies; x, position of 

 the animals when the direction of the rays was changed ; 1-4, trails made by butter- 

 fly 7/4 (right eye blackened) ; 5-6, trails made by butterfly 10/21-b (left eye black- 

 ened); 7-8, trails made by butterfly 10/24-a (right eye blackened). Note that 

 butterfly 7/4 (right eye blackened) failed to reorient promptly toward the side 

 of the blackened eye in the first two trials, but that in the third it did reorient 

 promptly in this direction, showing marked modification in behavior. This figure 

 and the preceding one are presented not merely to show the accuracy with which 

 Vanessa, with only one eye functional, reorients upon change in position of the 

 source of light, but also to show some of the peculiarities exhibited by different 

 individuals. 



THE JOURNAL OF EXPERIMENTAL Z05L0GY, VOL. 20, NO. 3 



