17 



an exact image ( I r ) of the maze is thrown on the recording 



table where the exj-erimenter can follow every movcme^nt of the 



animal during any j asaage through the maze. Actual records of 



these trij 3 are made by tracing on the record sheet v;ith a soft 



pencil the successive movements of the rat. (See Fig. 1) Theoe 



(5'i$.2) 

 tracings, measured with a chartometer shown by calibration to 



be accurate to within one j er cent, form the basis for the dis- 

 tance record. Since the maze is 6.4 tines as large as the 

 image, the distance record obtained in centimeters by the char- 

 tometer, must be multiplied by 6.4 to obtain the actual dis- 

 tance traversed in the maze. For example, if the distance 

 indicated by the chartometer is 121 centimeters we obtain the 

 actual distance run thus, 121 cm. x 6.4 = 7744 cm. The values 

 given in the tables represent the actual distance covered by 

 the rats. Both chart and maze distances were tabulated, and 

 the multiplications made to obtain the latter were checked on 

 the adding machine, In addition to tne distance record, such 

 charted pathways also furnish accurate account of the excess 

 effort expended, enabling a comparison as to the frequency and 

 extent of the several possible errors as well as a record of 

 the exact steps in their elimination. It can be determined 

 whether a certain error is lessened at each trial and finally 

 dlsaipears, or whether it is dropped out all at once. In 

 short, we have an accurate method of tracing the several fac- 

 tors in-'olved in the learning of the maze i robleni, and a basis 

 for the analysis of the learning process which has heretofore 

 been lacking. 



The exact method employed in this research concerning the 



