8i2 LIFE : OUTLINES OF GENERAL BIOLOGY 



*'as to have the appearance of a lot of shot poured out of a bottle 

 into the water". There is also a playful "porpoising", of which the 

 chief feature is an exuberant leaping out of the water; and there is 

 what is described as a game of "touch last" on the ice. A favourite 

 activity was to go aboard an ice-floe till it would hold no more, and 

 thus get carried by the tide to the lower end of the rookery, where 

 every bird would suddenly jump off and swim back against the 

 stream to catch a fresh floe and get another ride down. It thus 

 seems impossible to restrict the idea of play to the youthful period. 



But on the whole, play is a mode of behaviour characteristic of 

 the youthful period of certain well-endowed animals ; it is a precocious 

 exhibition of activities which are more or less anticipatory of those 

 characteristic of adult life, but are not yet in themselves of direct 

 or immediate utiUty. Its biological significance is partly as a safety- 

 valve for overflowing energy, partly as an early expression of 

 imitativeness, and partly as a correlate of pleasant feehngs, but 

 mainly as an irresponsible apprenticeship to adult activities and as 

 an opportunity for testing new departures, especially in habit. It 

 has four chief forms: movement-play, sham-racing, sham-hunting, 

 and experimentation. 



Since these characteristics of typical play are tolerably well- 

 defined, it is undesirable that the concept should be blurred by a 

 vague and loose application of the term. The following restrictions 

 may be suggested, (i) The term play should not be used for the 

 idle movements of animals, such as insects and fishes, unless there 

 is evidence that these are serving as an apprenticeship. Gregarious 

 swimming on the part of cuttlefishes and fishes, gregarious flying on 

 the part of insects and birds, may have no connection with migration, 

 or mating, or the quest of food — indeed, no utility at all, and yet 

 hardly deserve the name of play. Yet after all must there not be 

 something of elemental joy in the midges' dance, or the marvellously 

 sustained inter-swimming we have watched in Indian water-beetles ? 



(2) It is undoubtedly difficult to draw the line, but it seems well 

 to try to distinguish from typical play all activities that are bound 

 up with sex-display or courtship. For while these resemble play in 

 being artistic and spontaneous expressions of individuality, they 

 have an immediate outcome, though this may not be the conscious 

 or subconscious purpose of the players. They serve to arouse sex 

 interest and sex desire, whereas typical play has no such any imme- 

 diate reward. If it seem impossible to draw a line between play and 

 display, it may conduce to clearness if the word sex be used as a 

 prefix. Thus, though W. H. Hudson said that he spoke advisedly 

 of the fireflies' pastimes, it might have been clearer if he had spoken 

 of their sex-flight. Similarly one might use some phrase, such as 

 courting dance, for many of the extraordinary displays that birds 

 make at the breeding season. Thus Mr. Hudson portrays the dance 



