76 THE PLAY OF ANIMALS. 



ously need them. This premature appearance can not 

 be accounted for by inherited skill, because the inherit- 

 ance of acquired characters is extremely doubtful. Even 

 if such inheritance did have a part in it, the explanation 

 by means of selection would still be most probable, since 

 the utility of play is incalculable. This utility consists 

 in the practice and exercise it affords for some of the 

 more important duties of life, inasmuch as selection tends 

 to weaken the blind force of instinct, and aids more and 

 more the development of independent intelligence as a 

 substitute for it. At the moment when intelligence is 

 sufficiently evolved to be more useful in the struggle for 

 life than the most perfect instinct, then will selection 

 favour those individuals in whom the instincts in ques- 

 tion appear earlier and in less elaborated forms — in 

 forms that do not require serious motive, and are merely 

 for purposes of practice and exercise — that is to say, 

 it will favour those animals which play. Finally, in 

 estimating the biological significance of play at its true 

 worth, the thought was suggested that perhaps the very 

 existence of youth is largely for the sake of play. 



The animals do not play because they are young, but 

 they have their youth because they must play.* 



But I must call attention to another important phe- 

 nomenon that also has a direct relation to play, name- 

 ly, the imitative impulse. It was remarked in the pre- 

 vious chapter that while imitation is not an essential 

 feature of play, it is very often present. This is a suitable 

 place to notice this important subject, which will con- 

 stantly recur in the progress of our inquiry. First, it 



* [The author here adds several pages in which he suggests that 

 the conscious accompaniments of play — fully described in later 

 chapters — are also due to natural selection ; and points out the 

 " play comradeship " of young animals, saying, " Daher ist die 

 sociale bedeutung der Spiele ausserordentlich gross."] 



