HABIT FORMATION IN THE DOG 



55 



had been learned ; to note disturbances resulting from turning 

 the boxes 90°, 180° and 270° respectively from the first posi- 

 tion; and to make a retention-test after sixty days of rest. The 

 dog's eyes were then to be opened. After recovery they were 

 to be given their old problem boxes, for the puipose of noting 

 any change in method that might take place ; then each dog 

 was to be made to learn the three problem-boxes which the 

 other dog had learned while blind. The last part of this test 

 was not carried out on Dogs i and 2, since neither showed 

 enough evidence of vision to warrant the continuation of the 

 experiment. 



Figure 4 — Sketch of problem-box 4 



As to the animals used, Dogs i and 2, the temporarily blind 

 females used in the work on audition, have already been de- 

 scribed on p. 20. Dog 5 was a male of mixed breed— a cross be- 

 tween the bull-terrier and the black-and-tan — and was unusually 

 quick, active and strong. He performed many tricks, among 

 them jumping, catching a ball, etc., with great skill. Dogs 

 6, 7 and 8 were the offspring of Dog 5 and Dog 2. They were all 

 males, littered June i, 191 1, in the psychological laboratory 

 of the University of Chicago. Dog 6 was normal and cowardly. 



