THE GENESIS OF LIVING ORGANISMS 195 



stones. These areas, which are so exactly fitted into one 

 another, aie not left to blind chance, but are formed strictly 

 in accordance with law. If we wish to make a chemical pro- 

 cess responsible for the formation of the genetic building- 

 stones, we must suppose that certain cells affect their neigh- 

 bours chemotropically ; in this way we can imagine a hidden 

 chemical framework, which might possibly be adequate for 

 all that is required of it. 



But a chemical framework of this kind, in so far as its 

 expansion in space is concerned, differs in no way from a 

 mechanical framework, and its working is just as automatic. 

 If the germ were divided mechanically, the chemical frame- 

 work would likewise fall into two halves, and, just like any 

 mechanism, would lose, in so doing, the properties of a frame- 

 work. 



The conclusiveness of Driesch's experiments is as much 

 against the hypothesis of a chemical as of a mechanical frame- 

 work. It is quite immaterial whether we have before us a 

 mosaic held together by chemical or by mechanical agency — 

 the objections to the mosaic theory remain the same. 



THE THEORY OF FACTORS 



If we may not assume that any mechanism or chemistry, 

 however delicate and however fully in accord with plan, can 

 explain the genesis of the animal from the germ, we must 

 look about us for a third possibility. 



We are obliged to turn once more to the mode of genesis 

 of our implements, and to ask whether it is sufficient to 

 know the mechanical and chemical processes displayed in 

 the course of their manufacture. Into the construction of 

 any implement whatsoever there enter a number of processes, 

 which are independent of one another, but which link to- 

 gether in conformity with plan. Between the axe that cleaves 



