238 



BENJAMIN SCHWARTZ AND S. R. SAFIR 



per day. The reversal of the open corner was at first very con- 

 fusing to the creature. Upon being liberated in the chamber, 

 it ran to the closed corner, and remained there with greater stub- 

 bornness and persistence than had ever been witnessed before. 

 It was almost impossible to drive the animal in any other direc- 

 tion. Sometimes it would venture to the open corner but would 

 abandon it for the closed one. Gradually, however, it learned 

 to escape, although the effect of previous experience had no 

 influence on the rapidity of unlearning. The records are given 

 below : 



Day Closed Open Closed Open 



1 9 1 95 5 



2 17 3 85 15 



3 10 10 50 50 



4 11 9 55 45 



5 7 13 35 65 



SUMMARY AND CONCLUSIONS 



1. The fiddler crab shows a strong desire to liberate itself 

 from a trap, making on an average of thirty-five attempts an 

 hour. 



2. It goes persistently to a certain corner, even though escape 

 is rendered impossible by placing glass obstructions to prevent 

 it from climbing out. 



3. The hypothesis that dextrous males are inclined to go to 

 the right side, the sinistrous males to the left side, and females 

 equally to the center and both sides, is fairly well borne out by 

 experimental evidence. 



4. Taking advantage of the foregoing tendencies, the fiddler 

 crab may be made to reverse its proclivity, and escape from 

 a labyrinth through an opening at the opposite side. 



