Exfoliation 



The process is not accretive, but exfoliatory 

 a continual movement from within outwards. 

 When the desire or mental condition, which at 

 first was painfully conscious, has overcome opposi- 

 tion and established itself in altered bodily structure, 

 it has done its work, and becomes unconscious 

 the bodily function continuing for a long period 

 to act automatically, till finally it is thrown off 

 to make room for some later development. Thus 

 race-growth or Variation is a process by which 

 change begins in the mental region, passes into 

 the bodily region where it becomes organised, 

 and finally is thrown off like a husk. This may 

 be called the theory of Exfoliation. 



To illustrate our meaning. Let us take the 

 development of an eye. In the amoeba there 

 is a dim pervasive sensitiveness to light over the 

 whole body, but there is no eye, nothing that 

 we should call vision. Still this vague sensitive- 

 ness is of use to the amoeba. The shadow of its 

 prey falling upon the creature and exciting a 

 sensation hardly yet differentiated from touch 

 helps to guide its movements. On this dim sen- 

 sation it relies to some extent ; its attention is 

 directed towards it. Gradually, and in some 

 descendant form, there comes to be a point on 

 the body on which this attention is most specially 

 concentrated. The faculty is localised ; and from 

 that moment a change is effected there, a differen- 

 tiation and a special structure ; everything that 

 favours sensitiveness is encouraged at that place, 

 everything that dulls it is removed ; and before 



193 N 



