66 



ROBERT M. YERKES AND JOHN B. WATSON 



width of the strip. When these are to be used, Ji and J 2 are 

 removed, and any desired one of these strips inserted in their 

 places. Such a series, probably, will be adequate for the deter- 

 mination of the qualitative D. L. in animals. 



A? 



Figure 11 — The episcotister table. The two rotating sectors are driven by the 

 motor 77. The speed of the motor is controlled by the sliding resistance R. 

 The whole apparatus is mounted upon a rotating table, 74, the rotation of 

 which is controlled by a set of cords, in the hands of the experimenter, passing 

 around the drum S. The position of the sectors with respect to the two beams 

 is determined by the position of the carriage 46. 



