446 journal of Comparative Neurology and Psychology. 



impossible to use it further for the experiments. This seems to 

 indicate a good deal of individual variation and unfortunately the 

 specimens tried were not numerous enough to provide averages. 

 After the tenth day No. 40 was used for the experiments where 

 shadows alone were given at regular two minute intervals and 

 these series render further work with combined stimuli incompar- 

 able. 



TABLE n. 



Reactions of No. 40. 



No. Shadow. Touch, Time. No. Shadow. Touch. Time. 



II 



12 

 13 

 14 



15 

 16 



17 

 18 



zo 



23 o 



24 o " 



25 o 



26 o " 



27 o " 



28 o " 



29 o " 



30 o " 



In explanation of this increase in responsiveness to shadow alone 

 it seems possible that the shadow and touch have become so asso- 

 ciated that the occurrence of the one intimates the probability that 

 the other will follow. The response to touch is fairly uniform and 



