INTELLIGIBILITY OF EACH OTHER'S LANGUAGE. 337 



is understood both bj sheep and shepherd (Watson). The 

 horse learns to appreciate the cries of sporting dogs for 

 example, in the case of Houzeau's horse, who understood 

 the cries that intimated the successful driving of rabbits to 

 shelter, and that constituted a sort of call to both master 

 and horse to come and perform their share of the task in 

 the hunt. Various cries used as danger signals are under- 

 stood by animals of other species (Darwin). Various 

 animals understand have probably been taught by sad 

 experience to do so the signals of sentinel bees, when, for 

 instance, they warn off intruders (Figuier). 



A case is given in * Science Gossip ' of sparrows 

 understanding the call by bark of a terrier to be fed ; and 

 of both dog and sparrows remembering the feeding and the 

 call winter after winter. Ants of different species under- 

 stand each other's signs (Forel). Intercommunication of 

 suggestions, plans, wants, and wishes takes place between 

 the horse and cow (Macaulay). 



