THE HEREDITY OF RICHARD ROE. 



133 



to appropriate stimulation is that which especially dif- 

 ferentiates high animal organisms from low animal or- 

 ganisms. 



"Without this power and the plasticity which results 

 from it the multitudinous parts of high animals could 

 not well be co-ordinate, and therefore without it their 

 evolution could scarcely have been possible. Indeed, it 

 is not too much to say, so vitally important is this 

 power to the higher animals, that as regards them the 

 chief aim (if I may use the expression) of natural se- 

 lection has been to evolve it."* 



One more element, likewise of doubtful value, must 



be added to the inventory of Richard 

 Prenatal Rog Thig . g the element of prenata l 



influences. . 



influence on the part of his mother. 



In the process of evolution the development of the 

 female has brought her to be more and more the pro- 

 tector and helper of the young. She gives to her prog- 

 eny not only her share of its heredity, but she becomes 

 more and more a factor in its development. 



In the mammalia the little egg is retained long in 

 the body and fed, not with food yolk, but with the 

 mother's blood. The "gate of gifts" is not closed with 

 the process of fertilization as it is in the lower forms. 

 If the help of favourable environment can be counted 

 as a gift, this gate is not closed at birth nor so long as 

 the influence of the mother remains. By the growth of 

 the human family the parental environment becomes a 

 lifelong influence. The father as well as the mother 

 becomes a part of it. In Walt Whitman's words : 



" His own parents (he that had fathered him and she that had 



conceived him in her womb and birth'd him), 

 They gave this child more of themselves than that, 

 They gave afterward every day, they became part of him." 



*Archdall Reid, Science, December 17, 1897, p. 901. 



