32 



JOSEPH PETERSON 



346 more entrances to 1 (long) than did the control animals 

 for which 2 was left full length; they also made 18 more returns 

 to the starting place in the maze. This not only required that 

 2 shortened be passed more times than 2 long, but also with 

 greater probability of entrance for each time. It was noted 

 that rats entering 1 were likely thereby to be thrown out of 



Av. number 

 Per Period 



96-105 116-125 



Figure VII. — L shows rate of elimination of all entrances to cul de sac 1 long, 

 Maze IB, and S same for 1 short, Maze IIB. E' and E show corresponding 

 percentage eliminations. 



orientation and to make other errors. There can therefore be 

 little doubt that if 2 had been the only blind alley in the maze, 

 it would have formed no exception to the general rule. The 

 greater number of entrances to 4 shortened than to 4 long 

 (86 to 69) is due to the fact that rats emerging from 5 had a 

 strong tendency to run into 4. A glance at the maze will show 

 why this is to be expected. There were 32 more returns from 

 5 long than from 5 short; furthermore, entrance to 5 long had 

 the greater tendency to disorient the animal so that entrance 

 to 4 would be an increased probability. Just why 8 short 

 should have been entered 51% more than 8 long is not easy to 



