490 The Outline of Science 



are delightfully playful, and so are humble mammals like the 

 water-shrews, which few people know much about. Lambs have 

 many games, and goats have more; calves and foals have their 

 races; leverets and squirrels their frolics. One may distinguish 

 gambols, races, games like "tig," sham hunts, sham fights, and the 

 endless game of "experimenting" in which monkeys are pre- 

 eminent. Miss Romanes writes of her Capuchin Monkey: "He 

 is very fond of upsetting things, but he always takes great care 

 that they do not fall upon himself. Thus, he will pull a chair 

 towards him till it is almost overbalanced; then he intently fixes 

 his eyes on the top bar of the back ; and, as he sees it coming over 

 his way, darts from underneath, and watches the fall with great 

 delight ; and similarly, with heavier things. There is a washhand 

 stand, for example, which he has upset several times, and always 

 without hurting himself." This illustrates the game of experi- 

 ment. 



Similarly, Miss Frances Pitt records a game which two 

 ravens in a yard used to play with a cat. One of the ravens, with 

 a good deal of bluster, would make a frontal attack on the cat. 

 This was met on the cat's part by the usual arching of the back 

 and other expressions of contemptuous irritation. Meanwhile, 

 however, the other raven approached quietly from behind and 

 tweaked the cat's tail. Whereupon a rapid face-round, and the 

 second phase of the game began, in which the ravens exchanged 

 parts. There was no use in the performance ; it was only a "ploy" 

 in which the cat had its share. 



What is the biological significance of the play of young 

 mammals? It has been said that play is a good safety-valve for 

 overflowing energy and exuberant spirits ; it has been pointed out 

 that motion is linked in a subtle way to emotion, and that pleased 

 feelings naturally find expression in pleasant movements; it has 

 been suggested that the playing period affords opportunity for 

 trying new ways or exercising new gifts before the responsibilities 

 of life become too stringent. There is good sense in each of these 



