THE GROWTH OF GROUPS 175 



that one cannot imagine things varying in all directions. 

 Let us examine this assumption further by making the 

 attempt. A man is provided with a mass of clay and 

 ordered to break off small pieces of it and set them aside. 

 It is assumed that his mind is free from all constructive 

 ideas. It is certain that no two of the resulting pieces 

 of clay will be exactly alike, therefore they may be con- 

 sidered as things varying " in all directions." But they 

 are not actually so. However many of them were made, 

 they would be varying not in all directions, but in certain 

 directions, determined by the fact that they were the 

 work of man's hands. Among " all " we must include 

 numberless imaginable forms, too delicate to be formed 

 by hand. 



This illustration does not help us to understand the 

 meaning of the words "in all directions " as applied to 

 variation, and any such attempt to illustrate their 

 meaning will fail. But this formula is the basis of the 

 selection theory, as commonly understood. Hence it 

 seems that the basis is unreal. 



Let us, for the sake of argument, assume that the 

 pieces of clay are things varying in all directions. Though 

 they are not so, yet we can hardly get a clearer notion of 

 such things than is afforded by this illustration. Having 

 made this assumption, let us inquire into the effect of 

 selection upon the pieces of clay. The pieces are very 

 numerous, say a million in number, and no two of them 

 are alike. In order to bring about selection, we must 

 have a selective agent or agents, each with its own 

 special requirement or thing it wishes to select. Let 

 there be two human selectors ; the one requiring a thing 

 roughly cup-shaped, the other a thing sufficiently spherical 



