THE WHITE RAT AND THE MAZE PROBLEM 369 



TABLE II 



Comparison of Normal, Black-white and Olfactory Mazes 



Time of learning 



Olfactory 100%, Normal 145%, Black-white 175% 



* Initial— Olfactory 100%, Black-white 130%, Normal 370% 

 Final— Olfactory 100%, Normal 250%, Black-white 750% 

 Total— Olfactory 100%, Black-white 175%, Normal 330% 



Time 



Initial— Black- white 100%, Olfactory 115%, Normal 215% 

 Final— Olfactory 100%, Normal 110%, Black-white 143% 

 Surplus— Black-white 100%, Olfactory 138%, Normal 190%, 



Comparison of Open Maze with Enclosed Normal Maze of Same Pattern 



Time of learning 



Open maze 100%, Normal 100% 



Accuracy 



Initial— Open maze 100%, Normal 150% 

 Final— Open maze 100%,, Normal 225% 

 Total— Open maze 100%, Normal 140% 



Time 



Initial— Normal 100%, Open maze 105% 

 Final— Open maze 100%, Normal 120% 

 Total— Open maze 100%, Normal 110% 



sides to the alleys were high enough to prevent any outlook 

 to the neighboring runways and the light and odor were as 

 evenly distributed as possible. The second maze was of the 

 same plan but the true and the false paths were made to differ 

 decidedly in brightness values. The third maze, again of the 

 same pattern, had an olfactory trail in the true path. 1 The 

 figures from the open maze are not compared directly with the 

 others but with the score from the same maze when the re- 

 straining walls to the alleys were in place. 2 



We will not stop to comment upon the time of learning, as 

 the chief differences are seen in the accuracy records. The 

 olfactory maze heads the list in this respect both in initial, final 

 and total accuracy within the limits of the experiment. The 

 black- white maze follows second in initial accuracy and in total, 

 because of the initial, but falls far behind in final accuracy. 



1 In these tables the combined black-white figures are used, i.e., two groups of 

 animals of five each where the true path was white and the cul de sacs black, and 

 two groups of the same size where the conditions were reversed. The olfactory 

 records are those where the trail was in the true path since this seemed most typical 

 for our purpose. The combined olfactory scores make but little difference in the 

 rating, they simply somewhat lowered the scores in the early trials and raised them 

 in the final. For full details consult the previous papers. 



2 These mazes are all described in previous papers. 



