ORGANIZATION OF SOLS 



23 



brium liquid and suspended coacervate droplets, the equilibrium is 

 modified as a result of changes in temperature or composition in the 

 direction of a further dehydration (heating, addition of more sensiti2er), 

 vacuoles appear in the droplets. These represent separated equilibrium 

 liquid which has remained inside the coacervate droplets (Fig. 23). 



Fig. 23. Vacuolization by lowering the temperature of coacervate drops 

 consisting of gelatin sol + resorcin (from Bungenberg de Jong, 1932). 



Probably vacuolization by dehydration is comparable with the forma- 

 tion of vacuoles in the cell, since, in that case too, liquid is being 

 separated from the plasma colloids. 



Apart from this striking analogy, Bungenberg de Jong (1932) 

 mentions other models for cytological differentiation on the basis of 

 observations with coacervates. When mixing sols of gelatin, gum 

 arable and nucleic acid from yeast, two complex coacervates arise, in 

 addition to equihbrium hquid, one of which consists mainly of gelatin 

 and gum arable, the other being composed chiefly of gelatin and nucleic 



