8 JOSEPH PETERSON 



however, converted into two mazes as shown in figure I, by 

 means of a rearrangement of the partitions. Both mazes have 

 the same food box, and therefore only one of them can be used 

 at any one time in experimentation. IB (figure I) is a maze 

 with ten bhnd alleys, numbered from one to ten. The broken 

 line from the entrance, E, indicates the correct path to the 

 food. lA is another maze having but six cul de sacs, the entrance 

 being at E'. This maze is shown in the figure in heavier outlines. 

 Whenever the one maze was in use the entrance to the food 

 box from the other was, of course, closed. The mazes were 

 made of soft wood, and were stained black just before being 

 used in the present experiment. The alleys were uniformly 

 four by four inches in cross dimensions, and the partitions were 

 approximately one-half inch thick. By means of a number of 

 easily removable shutters, braced with triangular supports from 

 behind, the cul de sacs could be shortened as desired for the 

 purposes of the experiment. By this means each maze could 

 be converted quickly into a maze of a slightly different type, 

 having the same blind alleys but of relatively different lengths. 

 These shutters were also of soft wood stained black and had 

 the same cross dimensions as the alleys of the maze, so as to 

 fit tightly. In the figure these shutters are indicated by dotted 

 cross-lines in the blind alleys. Thus in Maze IB the blind 

 alleys 2, 4, 6, and 9 are shortened so that the ten blind alleys 

 together have a total length (about eleven feet) approximately 

 equaling the ten in Maze IIB, of which 1, 3, 5, 7, 8 and 10 have 

 been shortened as indicated. 



Maze lA differs from Maze IIA on another principle: all the 

 cul de sacs in the first are of full length, as indicated, while the 

 second has them all shortened. In lA the total length of the 

 blind alleys is about eight feet, while in IIA it is about four feet. 



The mazes were supplied with glass covers, with wooden 

 drop-shutters at the entrances and tin side-sliding shutters at 

 the food box entrances. In the experiments each animal was 

 first put into the food box and allowed to taste the food before 

 the first run, or trial. This was not only to strengthen the 

 incentive but also to insure uniformity in incentive and in 

 handling of the animal in all trials. In presenting the animal 

 to the entrance of the maze the experimenter was always seated, 

 with the* entrance slightly at his right. 



