Note 12 — Chapter II · Animal Intelligence; an Experimental Study of the Associative Processes in Animals[4] (continued 2)
Reading edition
FF was a box 40 × 21 × 24 inches, the door of which could be opened by putting the paw out between the bars to its right and pulling a loop which hung 16 inches above the floor, 4 inches out from the box and 6 inches to the right of the door.