222 THE BIOLOGY OF THE SEASONS 



play of experiment. Let us, first of all, consider play of 

 movement. 



" Most young things/' Hamerton says, " appear to 

 be reservoirs of pent-up natural energy that finds vent in 

 irrepressible gambols. But this takes specific forms in 

 different cases. Insects gambol in the air, birds among 

 the boughs, dolphins in the waves, and so on, endlessly 

 each in its own way. There is no use in it, except that the 

 nerves and muscles are trained for future work. The heart 

 beats more quickly, the breathing is more rapid, the 

 peripheral blood-vessels expand, and there ensues that 

 happiness which is the reflex of healthy function. 



Perhaps part of the significance of this simplest form of 

 play is to be found in the connection between pleasant 

 emotion and muscular movements. Such exuberance of 

 good spirits had the simple wood-chopper portrayed in 

 Thoreau's W alden, that when a thing amused him, " he 

 sometimes tumbled down and rolled on the ground with 

 laughter/' and perhaps we have here an expression of 

 primitive playfulness. 



When we see beautiful sights, or hear fine sounds, or 

 the like, sensory impressions have, of course, travelled into 

 our brains. But they do not, so to speak, stop there. 

 They set agoing other messages, which travel out to the 

 heart, which beats differently ; to the larynx, which 

 vibrates ; to the lungs even, and to other parts. In short, 

 internal muscular movements occur. As the result of these, 

 a third set of messages travel in again to the brain ; and 

 when the circle is completed, we are pleased. Perhaps in 

 this way one gets nearer an understanding of certain 

 gambols and of the vocal play the song of birds. The 

 latter seems to be due to internal muscular movements 

 associated with strong emotions. In any case, there is 

 reason to believe in a deep and subtle connection between 



