42 HARRY MILES JOHNSON 



released from the home-box. After prolonging this behavior, 

 she would suddenly proceed or turn back and choose the oppo- 

 site alley. Strange to say, some of her best "accuracy" records 

 were made during behavior of this kind. Dogs 3 and 4 insisted 

 on leaping over both grills from the beginning — even before 

 punishment was introduced. Later, rods were thrust through 

 the meshes of the wive forming the sides of the alley, which com- 

 pelled these dogs to creep under them and walk across the grills. 

 Both these animals usually consumed some minutes in hesita- 

 tion before choosing, after punishment was introduced, and 



