DIFFUSION AND OSMOSIS 



63 



nucleus, and a cytoplasm, which is in many cases entirely 

 separated from the membrane. These cells when united 

 form a veritable tissue, in all respects similar to the cellular 

 structure of a living organism. 



In the preparation showing artificial cells the cellular 

 structure is not directly visible until the gelatine has dried. 

 One sees only a gelatinous mass analogous to the protoplasm 

 of a living organism. This mass is nevertheless organized, or 



Fig. 9. — Tissue of artificial cells lormed by the diffusion in gelatine 

 of drops of potassium ferrocyanide. 



at least in process of organization, as we may see by the 

 refraction when its image is projected on the screen. 



During the cell-formation, and as long as there is any 

 difference of concentration in the gelatine, each cell is the 

 arena of active molecular movement. There is a double 

 current, as in the living cell, a stream of water from the 

 periphery to the centre, and of the solute from the centre to 

 the periphery. This molecular activity — the life of the 

 artificial cell — may be prolonged by appropriate nourishment, 



