QUANTITATIVE DETERMINATION OF LIGHT REACTIONS 237 



-121 



25% 

 59 



250/0 

 59 



25% 

 59 



a 



250/0 

 59 



Fig. 7 A set of trails made under lights of 25 per cent difference, by a sym- 

 metrically responding larva; a, the test trails; b and c, the trails made under the 

 influence of the opposed lights. 



Fig. 8 A set of trails made under light of 25 per cent difference, by an asym- 

 metrically responding larva; a, the test trails; b and c, trails made under the 

 influonce of the opposed light. 



THE JOURNAf. OF EXPERIMENTAL ZOOLOGY, VOL. 17, NO. 2 



