EXPERIMENTS AND OBSERVATIONS 45 



category of " not seen ", 44 in the " seen ", and 39, i. e., 

 a third of the total, in the " undecided." The percentage 

 of correct answers for these three categories were, respec- 

 tively: 24%, 82% and 72%. Here we have once more 

 approximately the same ratio between the categories of 

 " seen " and " not seen " as in the case of the tests with 

 the smaller blinders. If we were to count the cases 

 which we had put under the head of " undecided," in the 

 same category as those in which vision had been ex- 

 cluded — as Mr. von Osten had done — then one would 

 have been led to the conclusion that the horse did not 

 need visual signs. Several observers had thus been led 

 astray : e. g.. General Zobel writes in the " National- 

 Zeitung" (Aug. 28, 1904), that upon request Mr. von 

 Osten had covered Hans's right eye " by means of some 

 sort of blinder, so that he was unable to see his in- 

 structor ", and that Hans did not fail to respond cor- 

 rectly. We evidently have here to do with the unreliable 

 bolster mentioned above. Furthermore, Mr. Schillings 

 made a number of tests with the small blinders, in which 

 50% of the answers were correct, and probably in the 

 same manner were obtained the results published in one 

 of the daily papers (the " Berliner Tageblatt ", Dec. 12, 

 1904), several days after the publication of the December 

 report, and reading as follows : " Tests have been made 

 upon Hans with blinders over his eyes and it is to be 

 noted that, in spite of these, he still responds correctly." 

 Mention is also made of the experiments noted in Supple- 

 ment III (page 257), in which Mr. von Osten hid be- 

 hind the questioner and merely encouraged the animal 

 by occasional exhortations, but it is not possible to say 

 with any degree of certainty in how far he was really 

 hidden from the horse's view. 



