10 STELLA B. VINCENT 



there is a devious way to learn which involves many turns and 

 the possibility of many false turns. The final escape to food takes 

 a time which varies from two hours per trial at the beginning 

 to ten seconds when the problem is learned. The habits set up 

 by the brightness contrast, whether depending upon discrimi- 

 nation or not, clearly cannot be carried over advantageously to 

 a situation where the contrast does not exist. It may easily 

 be conceived also that the motor habits involved in the simpler 

 reactions described above for the problem box which bring the 

 rat immediately to the presence of its food might be disastrous 

 and delay the acquisition of a reaction depending upon the 

 co-ordination of a long series of acts and extending over a con- 

 siderable period of time. 



As the learning of this maze has been so fully and freely dis- 

 cussed before all mention of it will be neglected here and any 

 facts of interest concerning it will be brought out in the com- 

 parison of the two mazes which will follow later. 



BLACK AND WHITE MAZE 



The outcome of the tests on the black and white maze was 

 noticeably unlike that of the normal maze. The differences were 

 seen in the behavior of the animals and appear in the numerical 

 results and the graphs plotted from them. They were con- 

 firmed and checked by the data furnished by the blind animals 

 and by the facts brought out in the box experiments. 



Success in .such a problem has several measures: (a) the time 

 taken relative to the total distance, i.e., speed; (b) the number 

 and distribution of the errors, i.e., accuracy; (c) the time of 

 learning, i.e., the number of trials in learning; (d) the surplus 

 values of time and errors; (e) the rate of elimination, i.e., dis- 

 tribution of effort; (f) the form of the learning curve — a picture 

 which reveals some of the complex relationships existing among 

 the various factors. In this paper the burden of proof will be 

 put upon accuracy and speed, since it was in these two respects 

 that the greatest divergence was seen. The other criteria, how- 

 ever, will not be entirely neglected. 



In the interest of clearness as well as of time and space, the 

 results from the four groups of animals, trained and untrained, 

 for the black and for the white maze, will be combined and 

 presented as a whole. The differences were unessential. Any 

 evidence of training being carried over from the box to the 



