60 THE NATURE AND ORIGIN OF LIFE 



common to all living bodies. But it does not follow from 

 the definition. It is a theorem to be demonstrated by 

 experiment the morpho-biological theorem. Such a 

 theorem we shall develop later. 



On the other hand, the fact neglected in seeking for a 

 chemical definition of elementary life the phenomena of 

 colloidal structure makes us think that the approximate 

 law of assimilation, which is so far purely chemical, may 

 turn out more approximate than it seems when we take into 

 account differences of colloidal state capable of masking it. 

 When we spoke of the substance of calf or goat, we used 

 expressions clearly inexact ; for in the calf as in the goat 

 there are liver and lights, muscle and nerve. But suppose 

 for a moment what I hope the future will clearly show us 

 that liver and lights, muscle and nerve, are only different 

 colloid states of identical chemical substances (the fact 

 that the same tissues exist in all mammals is sufficient to 

 make us consider the hypothesis plausible). Then the law 

 of assimilation becomes almost as evident in the develop- 

 ment of a child as in the multiplication of a bacterium. 



