II. COMPARISON OF LEARNING-TIME AND LEARNING-METHODS 

 IN BLIND AND IN NORMAL DOGS 



The behavior of the two temporarily blind dogs used in the 

 experiments already described suggested another problem for 

 which the animals could be used as material. It is evident that 

 an animal trained to open the "puzzle-box" used by Thorn- 

 dike ' in work with cats and other animals and by Watson - 

 and others in experiments on the white rat, must make a 

 complicated and delicate adjustment in a minimal time. It 

 should be interesting to ascertain to what extent the dog makes 

 use of vision in making this adjustment ; and to compare the 

 methods employed by blind and by normal dogs in learning 

 such problem. Further, these dogs had learned to behave in 

 their ordinary environment practically as normal dogs, although 

 none of their "spatial world" was "visual space." The " Moly- 

 neaux problem" is at once suggested, and it becomes of interest 

 to note any changes in behavior concurring with the formation 

 of a world of \-isual space. 



Six food-boxes were constructed for this problem of 2'' x 2'' 

 white pine framework co^'ered with steel woven w4re having a 

 mesh about i cm. square. These boxes were each 30" wide, 

 24" long and 24" high. A door I2"xi2" was cut in one of 

 the 30" X 24" sides, and hung so as to be opened by a coiled 

 spring when the latch was released. A sketch of one of these boxes 

 is shown in Figure 4. The boxes will hereafter be referred 

 to by number. The kind of latch and hanging of the door to 

 each box is shown below. 



The program was to have each dog while yet blind learn a 

 separate set of three boxes; then to note what disturbance, if 

 any, followed total darkening of the room in \\-hich the work 



' Thorndike, E. L. Animal Intelligence. 

 ^Watson, John B. Animal Education. 



54 



