ANIMALS' ILLUSIONS 163 



of illusion. Old-fashioned people used to identify any 

 strange living object which frightened them with l the 

 devil/ Perhaps for horses 'the devil' is anything 

 which they cannot understand. 



* Understanding/ or investigation to that end, does 

 often remove these equine illusions. Young horses can 

 be led up to a sack lying on the ground and induced to 

 pass it by letting them smell it, and find out that it 

 really is a sack, and not the Protean thing, whatever it 

 may be, which illusion conjures up for them. Once the 

 writer saw a very quick and pretty instance of experi- 

 ment by touch made by a frightened pony. It was 

 being driven as leader in a pony tandem, and stopped 

 short in front of where the rails of a steam-tramway 

 crossed the road. It first smelt the near rail, and then 

 quickly gave it two taps with its hoof. After this it 

 was satisfied, and crossed the line. On the other hand, 

 a donkey always tried to jump the shadows of tree- 

 trunks on the road, though a similar experiment of 

 touch would have^shown that these were as unreal as the 

 tram-rail was substantial. Lastly, no horse which has 

 once knocked its head against the top of a stable door- 

 way seems quite able to get rid of the illusion that there 

 sits up in the top of all doorways an invisible something 

 which will hit him again next time he goes through. 

 Hence the troublesome, and sometimes incurable, habit 

 of horses ' jibbing ' at any doorway they may be required 



II 2 



