210 The Science of Life. 



According" to Groos, play is the outcrop of instincts 

 which have been evolved like other instincts, arising" by 

 congenital or germinal variation, and fostered in virtue 

 of their utility. But what can be the utility of play, 

 which by definition has no serious purpose? 



To this Groos answers that play is of fundamental 

 importance as "the young form of work". The play 

 period is an apprenticeship, a preparation for adult life, 

 with the great advantage that mistakes are not of seri- 

 ous moment. Throughout the ages those kittens and 

 other young- carnivores which hunted best in fun have 

 hunted best in earnest; the non-players and the bad 

 players have been eliminated. Play is thus a rehearsal 

 without responsibilities, a sham-fight before the battle 

 of life begins, a preliminary canter before the real race. 

 In short, as he says, while there is some truth in the 

 assertion that animals play because they are young, it 

 is perhaps as true that they have a period of youth in 

 order that they may play, and the forms of play have 

 been defined in relation to the realities of adult life. 



A second justification of play is found in the simple 

 fact that it affords opportunity for the exercise and 

 perfecting of instinctive activities, which, therefore, do 

 not require to be so definitely engrained in the cerebral 

 constitution. Thus, it may be said that play is a device 

 which lightens the burden of inheritance. 



It is certainly a suggestive idea that the play-period 

 affords scope for the rise and progress of new varia- 

 tions before the struggle for existence has become 

 keen. It affords what the Germans call Abanderungs- 

 spielraum elbow-room for initiatives, new departures, 

 idiosyncrasies, which form the raw material of progress. 

 The importance of this biological justification of play 

 in relation to human children is obvious. 



There are few great facts of life in regard to which 

 precise observation and critical interpretation would be 

 Psychoiogi- more welcome than in regard to animal 

 cai Aspect courtship. Here, even in spite of himself, 

 f Mating. tne biologist m ust become a psychologist. 

 The historical aspect of the question admits of brief 

 statement. (a) Long before Darwin's day, naturalists 



