EXPLANATION OF OBSERVATIONS 187 



relevant experiments. I have thus far tested twenty-five 

 horses of different kinds, from the imported Arabian 

 and English full-blood, down to the heavy draft-horse. 

 The experiments were made partly in the courtyard of 

 military barracks, partly in the circus, and partly in a 

 riding-school or in private stalls. I am specially indebted 

 for kind assistance to Messrs. von Lucanus, Busch, and 

 to H. H. Burkhardt -Foottit and E. Schumann, the two 

 excellent trainers connected with the Busch Circus. 

 During these tests, the horses were always amid circum- 

 stances familiar to them, whether free or bridled, under 

 a rider or hitched to a wagon. All aids or signals, except 

 the calls, were eliminated in so far as it was possible. ^^ 



The results of those tests were in substance as follows : 

 Many horses react to a smack of the lips by a rather fast 

 trot. Many stop on the cry " Hola " or " Brr ". This / 

 last was nicely illustrated in the case of two carriage j 

 horses supplied with large blinders and held with a loose ; 

 rein, and hitched to a landau. One of them regularly 

 stopped when the " brr " was given by the driver, i 

 whereas the other, which had not been habituated to this i 

 signal, kept serenely on the trot, so that the vehicle i 

 regularly veered off the track — a sure sign that no un- 

 intentional aid was being given by means of the reins. 

 Other horses, again, were accustomed to halt in response 

 to a long-drawn-out " hola ", but it was the cadence of 

 melody rather than the word that was effective, since 

 any other word, or even a series of inarticulate sounds, 

 would produce the same result, provided they were given 

 with the proper inflection. When this was changed, then 

 the response would fail. v, _, 



The result was not so apparent when it came to con- 

 trolling the kinds of gait. One riding-school horse, when 



