44 



FREDERICK S. BREED 



upon the flock of chicks in the cage below and also an outlet 

 through H which was 8.5 cm. wide. The door of galvanized 

 sheet iron could be inserted here to close the exit when desired. 

 Once in I, the chick joined the rest of the flock by passing down 

 over the door of the cage that was turned up toward this end 

 of the apparatus at an angle of about 45 degrees. The dimen- 

 sions and details were the same by either of the routes a chick 

 might take from A to the cage. K indicates a key by which 

 the circuit was made and broken. The current was supplied by 



Figure 9 — Perspective of apparatus for testing habit-formation, ground plan of 

 which is presented in fig. 8. 



a no. 6 Columbia dry cell which was connected with the primary 

 coil of a Porter inductorium, the secondary coil of which was 

 in circuit with the ends of the two wires that were wrapped 

 parallel to each other about floors that were fitted into the 

 electric chambers E. During the tests the apparatus was so 

 placed that the entrance box was nearest the source of light 

 and the sides of the apparatus were symmetrically situated with 

 reference to the two windows that admitted the light. The 

 cards used at D were 14.25 x 19.5 cm. and those at F 13.5 x 



