136 HELEN B. HUBBERT AND K. S. LASHLEY 



errors of type I and not of type II? If such association, in the 

 sense of a serial formation of conditioned reflexes, is an important 

 principle in habit-formation it must be obscured by other agents 

 in the elimination of errors of the second type. If not, it is for 

 some reason simulated in the elimination of errors of type I. 

 An inquiry into the relative complexity of the factors influencing 

 the elimination of the two types of errors gives data which seems 

 to favor the latter possibility. Movements toward the center 

 of the maze are much more influenced by gross orientation than 

 are those of turning to the right or left. After the third to sixth 

 trial the rats run with their heads near the convex (inner) walls 

 of the alleys of the maze and almost invariably confine their 

 efforts to climb out of the alleys to these partitions. Such be- 

 havior becomes more pronounced as they approach the center 

 of the maze and persists until the limits of training are reached. 

 It is improbable that this is a reaction to the odor of food in 

 the center of the maze, first, because it does not occur during 

 the first trials and second, because smearing the maze with food 

 does not alter the reaction essentially. It may be a reaction to 

 the curvature of the sides of the alleys but such an association 

 seems improbable in view of the slowness with which similar 

 sensory habits are formed in the discrimination box. The final 

 alternative is that of an orientation to the maze as a whole. 

 The work of Carr shows that the animals are usually well oriented 

 with respect to the direction of the food compartment from the 

 starting box and may even depend upon the direction of the 

 maze from their home cages for orientation. The behavior of 

 the rats strongly suggests that they very soon acquire this sense 

 of direction in the maze and that as they approach the center 

 of the maze the orientation becomes more certain, perhaps by 

 the summation of familiar stimuli, perhaps by the closer approx- 

 imation of the visible objects above the maze to their appear- 

 ence from the food-box. 



The conditioning stimuli to an orientation determined either 

 by the curvature of the alleys of the maze or by the visible 



tracing of this part of the path. This is evidence for an additional interfering 

 agent in the elimination of errors 10 and 11 which does not act in the case of the 

 other errors and justifies the view that the elimination of these errors is not directly 

 comparable with that of the others. In the experiments reported here every effort 

 was made to prevent this retracing of the path. The moment the animal entered 

 the food-compartment the experimenter hastened to close the doorway between 

 alleys e and /, and in very few cases did the rats escape into the outer alleys. 



