Imitatiofi. 185 



must be brought up apart from their parents or other 

 members of their kind. If they still exhibit the activities 

 in question, such as the love-antics of many birds in the 

 pairing season, there is probably an instinctive basis, and 

 we may fairly conclude that the performance is handed on 

 in all its definiteness through hereditary transmission. 

 If they fail to exhibit the activities, other conditions being 

 as far as possible normal, the probabilities are that the 

 performance is traditional and due to imitation. 



But though we must thus carefully distinguish between 

 what is congenital and instinctive on the one hand, and 

 what is acquired through imitation and handed on by 

 tradition on the other hand, we must not forget that, in 

 animal life, as it presents itself to our observation and 

 interpretation, the two factors often combine to form what 

 we have termed instinct-habits. Instinctive procedure is 

 modified and moulded under the guiding touch of acquired 

 experience. And there are probably many activities, such 

 as the flight, and perhaps the song, of birds, which are 

 founded on an instinctive basis, which are quickened 

 through imitation, and which reach completion by much 

 practice and that constant repetition under the guidance 

 of individual experience which leads onwards to perfected 

 habit. 



