352 THE FIRST ORGANISMS 



in other drops, each system having its own characteristic 

 pecuHarities. 



What were the conditions which determined the existence 

 of any coacervate drop in the waters of the primaeval hydro- 

 sphere? Complex coacervates obtained artificially, by simply 

 mixing solutions of two differently charged colloids, are, as 

 we have seen, formations with a static stability. The greater 

 or less duration of their existence is determined by the condi- 

 tions of solubility or the presence of surface membranes and 

 is associated with the maintenance of the constancy of the 

 properties of the system in time. 



Thus, in such a coacervate drop, the slower any particular 

 change takes place and the more constant the surrounding 

 medium remains, the greater will be the stability of the 

 system and the less its chance of disappearing as an individual 

 formation during the time it is under observation under the 

 conditions of a laboratory experiment. 



This, however, was not the sort of stability manifested 

 by the systems which played the decisive part in the evolution 

 of matter on the way to the origin of life. This evolution 

 could only proceed on the basis of interaction between the 

 systems and the external medium in contact ^vith them, i.e. 

 on the basis of the formation of open systems. We must 

 remember that the coacervate drops, w^hich arose somehow 

 in the primaeval hydrosphere, were immersed, not simply in 

 water, but in a solution of various organic compoimds and 

 inorganic salts which were certainly capable of entering into 

 the coacervate drop and interacting chemically with the sub- 

 stances of which it was composed. If we do so it will be clear 

 to us that under these conditions the stability of the drop could 

 not retain its static nature. The drop would, to some extent, 

 assume the character of an open system. 



This would occur specially readily when the actual 

 formation of the drop was based on a previous chemical 

 organisation in time like that postulated by M. Sugita.^ 

 However, let us suppose that the drop arose under purely 

 colloidal conditions, that the whole process of its formation 

 resulted simply from the concentration of protein-like sub- 

 stances and others of high molecular weight at a definite place, 

 and from the formation of a surface membrane separating 



