56 THE HORSE OF MR. VON OSTEN 



same results, or approximately the same results in the 

 case of Mr. von Osten that it did for Mr. Pfungst and 

 Mr. Schillings, but unfortunately he declined to act as 

 subject. In the meantime, however, new and decisive 

 proof presented itself which destroyed all possible doubt. 



Before adverting to it, let us consider in a few words 

 the reaction-time of the horse, — the time elapsing between 

 the final sign of the questioner and the reaction of the 

 horse (i. e., the back-step). Unfortunately this time can- 

 not be directly determined. All that can be ascertained 

 from our time-measurements, is the time intervening 

 between the moment of the head-jerk and the moment in 

 which the reaction of the horse is noted. (See page 51). 

 This time averaged, for the 127 measurements, .45 sec- 

 onds. If we stated the unavoidable error, (obtained on 

 the basis of extended supplementary measurements which 

 it is not necessary to consider here) as .15 seconds, and 

 apply it to the value found above, we obtain .3 seconds 

 as the probable reaction-time of the horse.* 



That the tapping — as well as all other movements of the 

 horse — was nothing other than a reaction upon certain 

 visual stimuli, was proved beyond a doubt by the fact that 

 the voluntary execution of the head-jerk and of other 

 movements — which we will describe in more detail later 

 on, — ^brought about all the proper responses on the part of 

 the horse. Thus, artificial synthesis became the test 

 of the correctness of analytical observation. 



To elucidate ; if the questioner retained the erect posi- 

 tion he elicited no response from the horse, say what he 



* See page 126 on the corresponding reaction-time in the case of man. 

 Similar tests have been made in the case of animals in only one instance, 

 and that for dogs, by E. W. Weyer.' But, as might have been expected, 

 they did not yield any satisfactory results. 



