APPARATUS AND METHOD FOR MAZE 



The apparatus used in the present experiment comprised 

 for the most part the Watson Circular Maze (Figs. I. & II.) 

 somewhat modified. The paths were 12.7 cm. in width 

 and were partitioned off by vertical sheets of aluminum 

 13 cm. in height, set in grooves of a circular wooden base 

 189 cm. in diameter. The goal was 35.5 cm. in diameter. 

 Two semicircular sections of wire mesh covered all but the 

 center of the maze, which was covered by two separate 

 semicircular sections. The distance from the entrance to the 

 center of the maze was approximately 560 cm. This enlarged 

 pattern of the original maze was used because it allowed the 

 animal greater freedom of movement and at the same 

 time presented a greater difficulty in obtaining cues from 

 the walls of the alleys. 



The entrances to the alleys were located alternately in 

 adjacent quadrants of the same arc. The radial stops in 

 the alleys were placed diametrically opposite the entrances 

 to the same alley, thus rendering it possible for a rat to 

 travel only one half the circumference of the maze in any 

 one direction from the entrance. No stop was placed in 

 the alley around the center. 



The camera lucida attachment was employed in the 

 present experiment. This attachment consists fundament- 

 ally of two mirrors and an achromatic lens by means 

 of which the maze and its contents are reflected in miniature 

 on a convenient holder where the observer may plot the 

 course of the rat's pathway through the maze. The camera 

 lucida is described fully by Watson (20). In the present 

 maze a further alteration from the original consisted in 

 placing the lights higher up from the pathways, thus pro- 

 viding uniform illumination and avoiding shadows to a 

 greater extent than possible in the original design. 



The object in using the above attachment was to obtain 

 a graphic record of each day's trial. It was the desire in 



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