PROTOPLASM. 51 



been previously heated to a temperature of 5O-6o C., an acid from the 

 oil splits up the potassium carbonate, liberates carbon dioxide, and forms 

 an extremely fine emulsion. Drops of this show a structure not unlike 

 that of cytoplasm, exhibit movements and streamings not unlike those 

 of Amoebae, and are, in short, mimic cells. Just as a working model 

 may help us to understand the circulation, so these oil-emulsion drops 

 may help us to understand the living cell, by bringing the strictly vital 

 phenomena into greater prominence. 



