234 SOCIAL BEHAVIOUR 
and the stages of its evolution are hidden from our view. 
All we can say is, that it is possible to trace in animal be- 
haviour some of the instinctive tendencies and intelligent modes 
of accommodation to social circumstances, together with the 
germs of imitation, intercommunication, and tradition, and the 
establishment of bonds of sympathy, without which the subse- 
quent stages of evolution would be inconceivable. 
