12 THE PLAY OF ANIMALS. 



it a full comprehension of human and animal play can 

 be obtained, must receive a negative answer; for, while 

 simple overflow of energy explains quite well that the 

 individual who finds himself in a condition of overflow- 

 ing energy is ready to do something, it does not explain 

 how it happens that all the individuals of a species 

 manifest exactly the specific kind of play expression 

 which prevails with their own species, but differs from 

 every other. " Every species," says Hudson most truly,* 

 " or group of species has its own inherited form or style 

 of performance; and however rude and irregular this 

 may be, as in the case of the pretended stampedes and 

 fights of wild cattle, that is the form in which the feel- 

 ing will always be expressed." Such a fact, depending 

 as it does on the phenomena of hereditary transmission, 

 evidently can not be explained by simple overflow of 

 energy in an individual. Spencer has attempted to make 

 use of the theory of imitation to point out the how and 

 why of play activity. But we have seen that the most 

 elementary and important plays can not be referred to 

 it. It thus becomes necessary to call in the aid of some 

 other conception of the subject. The solution of the 

 problem is near at hand. Instead of pressing the idea 

 of imitation exclusively, it is necessary to include that 

 of instinct in general. Spencer himself has approached 

 the right understanding of the problem. When he asks, 

 What acts are chiefly imitated? — he reaches the con- 

 clusion, chiefly such actions as " in the life of this par- 

 ticular creature play the most important role." f 



And proceeding to give some examples of this, he 



* Loc. cit., 281. 



f Principles of Psychology, ii., p. 709. See Wallaschek as above : 

 the imitation of actions that are " essential for the preservation of 

 life." 



