Human Infancy and the Recapitulation Theory 73 



ized. As to its origin, plasticity is characteristic in small degree 

 of animals other than the higher mammals, but mutations in 

 this direction with their coincident delayed maturity were futile 

 until accompanied by the protection of parents. Plasticity is 

 for this reason conspicuous with mammals. In turn the assump- 

 tion of valuable habits had the effect of preserving and selecting 

 germinal mutations in a given direction which would otherwise 

 have been sacrificed. Finally, the vital energy necessary to the 

 production of organic complexity in the higher learning animals 

 was made possible in some part by the saving from a lowered 

 birth-rate due to the increasing parental care and solicitude 

 given to the eggs and the immature young. 18 



Two recent volumes from the pens of accomplished naturalists 

 discuss the infancy and youth of animals in a convenient and 

 exceedingly attractive fashion. 19 In the main these books con- 

 firm the earlier accounts, but with important minor qualifications. 

 The economic value of parental care as a substitute for great 

 fertility in biological competition is accepted and illustrated by 

 both writers. Pycraft, however, refers to "some puzzling facts" 

 and rejects the view which finds in the mortality of young a 

 cause of exaggerated fertility. Rather, it should be said, fertility 

 encourages mortality by offering large numbers of young for food. 

 Fertility, like extravagance in ornament and gorgeousness of 

 color, is to be regarded as a specific character and not a direct 

 response to biological necessity. Moreover, the relation of 

 fertility to mortality can often be only surmised, from ignorance 

 of the actual natural conditions surrounding many species. It 

 still does not appear that Pycraft's position need be in essential 

 contradiction to the older way of stating the matter, which 

 perhaps failed to clearly affirm that the only effect of selection 

 was the limitation or survival or inherent specific characters. 

 There seems to be small reason for doubting the broad correlation 

 of decreasing fertility and degree of parental care in relation to 



M The following extract from Washburn's Animal Mind, 1908, p. 284, should be 

 reported in this general connection: " One of the most vital meanings of the long period 

 of helplessness and dependence constituting human infancy lies in the fact that by 

 relieving from the necessity of attending exclusively to external objects, it renders 

 possible attention to the sensations resulting from movement; and thus, by supplying 

 an essential condition for the revival of such sensations in idea, it opens the way for 

 the control of movement through the movement idea." The extract should be read 

 with its context. 



Mitchell, The Childhood of Animals, 1912. Pycraft, The Infancy of Animals, 1913. 



