EXPERIMENTS AND OBSERVATIONS 83 



The interpretation of this series which it would be hard 

 to explain by a reference to the colors which were mis- 

 taken, is simply this: Cloths lying near together were 

 regularly mistaken on the part of the horse. 



Experimental control of the questioner's movements 

 decided the question. If the questioner at first indicated 

 the proper direction and then turned about after the 

 horse had already started forward, he was as a rule mis- 

 led. When the questioner did not face the cloths at all, 

 but turned away at right angles, or when he turned his 

 back upon them, Hans was completely at sea. If, on 

 the other hand, the cloths were arranged, not in a row, 

 but in several heaps, so that one might turn to a particular 

 heap, but could not indicate a particular cloth, then Hans 

 would regularly go to the proper heap, but would always 

 bring forth the wrong cloth. After much persuasion Mr. 

 von-Osten consented to make a series of these tests him- 

 self. Hans's failures were deplorable. He \vould take 

 up first one cloth then another, turn again to the first, etc. 

 We would mention, however, that this apparent searching 

 was not done spontaneously, but in reponse to Mr. von 

 Osten's calls, such as "See there!", "The blue!", etc. 

 Every time Mr. von Osten called, Hans would drop the 

 cloth he was holding in his mouth, or he would turn away 

 from the one he was about to grasp, and would then try 

 another one. 



In addition to these visual signs, the horse received 

 auditory signals in these tests, (as in all others in which 

 he was required to bring objects). As soon as the ques- 

 tioner noticed that Hans was about to take up the wrong 

 cloth, all that was necessary to make him correct his error 

 was to give some sort of an. exclamation, such as 

 " Wrong! ", " Look, you ! ", " Blue ! ", etc. Hans would 



