HABIT FORMATION IN ALBINO RATS 25 



IV. EXPERIMENT 2: THE PRELIMINARY INCLINED PLANE 



The apparatus used in this experiment (see Plate VI) was 

 designed especially to make a problem exceptionally difficult to 

 learn, and in this purpose it exceeded expectations. The basic 

 principle is the same as that of the apparatus designed and used 



Plate 1ZI. The Inclined "Plant. 



by Watson in his experiments at the University "of Chicago, 

 called by him the " Inclined Plane," and which is described and 

 illustrated in his monograph "Animal Education," page 37. 5 

 But my apparatus differs from his in several respects. 



Plate VI shows in detail the construction and method of 

 operation. The food box, A, is framed of wood, eleven by 



5 Watson: Animal Education, Chicago, 1903. 



