Human Infancy and the Recapitulation Theory 71 



survival. This degree of efficiency involves some practice in 

 all learning animals and in many a long continuation of it. 

 This indispensable practice would be fatal if left to the period 

 of independence. It might conceivably have been enforced by 

 parents, as it is to a very slight extent among animals, but this 

 implies a degree of intelligence and foresight beyond the capacity 

 of animal parents, indeed not easily assumed by civilized human 

 parents with all their higher resources. Self-imposed practice, 

 or play, was therefore the simplest biological expedient. If 

 the formula of Groos be understood to assert that infancy without 

 play is useless, its truth must be admitted, and it is fair to assume 

 that infancy and play evolved together. A merely docile plastic- 

 ity could scarcely give rise to the habits of maturity. Play is 

 the necessary middle term between plasticity on the one hand 

 and intelligence on the other. 



These several additions to the ideas of Fiske are brought to- 

 gether in Baldwin's "Development and Evolution" (1902), per- 

 haps without explicit reference to their bearing upon a theory of 

 infancy as such. Their interrelations are, however, there shown. 

 The doctrine of "organic selection," also reported in this book, 

 is not without its implications for the present topic. 17 This 

 theory was presented by three writers independently — Osborn, 

 Lloyd Morgan, and Baldwin — and has obtained a fairly general 

 acceptance. Its general effect is to show how plasticity has 

 determined in part the selection of non-plastic or fixed or- 

 ganic characters. It must have been noticed in the reported 

 statements of Fiske that the evolution of both reflex or instinc- 

 tive and intelligent behavior was explained in terms of use- 

 inheritance. This explanation was not inconsistent with the 

 views prevailing at the time Fiske wrote, but has come to be no 

 longer tenable by reason of the change of emphasis since regard- 

 ing the transmission of acquired characteristics. It was inevi- 

 table that plasticity and its effects should be made to accord 

 with the more acceptable doctrine of the germinal origin of 

 variation and mutation. 



Organic selection assumes that although plasticity is physically 

 inherited its resulting habits are not. But these habits, because 

 of their effect in making adaptations more adequate, would 



17 See Appendix B for the original statements with others. 



