46 PLANT LIFE 



remain in this condition for about four days 

 the strong salt solution is gradually replaced 

 by sea-water. The ellipsoidal cells swell out 

 until they approximately fill the space they 

 previously occupied within the old membrane. 

 But the disunion has obliterated the mutual 

 relationship formerly existing between cell 

 and cell. Each one proceeds to develop with- 

 out any reference to the rest, and puts out a 

 basal attaching organ below, which usually 

 penetrates the adjacent cell cavity. Later 

 on the cell also proceeds to grow in the 

 apical direction. Thus the individual cells 

 of the filamentous colony have been, in this 

 experiment, released from the influence which 

 bound them together into an organism, and 

 have recovered complete autonomy and in- 

 dividuality. This has occurred as the result 

 of sundering the protoplasts from all com- 

 munication with one another for the period 

 of time during which they remained con- 

 tracted in the strong salt solution. 



An experiment such as this is specially 

 valuable, since it enables us to appreciate 

 not only the reality of the continuous inter- 

 change of material between cells that are 

 in close contact, whereby co-ordination is 

 rendered possible, but it serves to show how 

 closely this co-ordination to form an organism 

 is bound up with such mutual interchange. 

 For the protoplasts, although separated by 

 membranous cell walls from each other, 

 are yet in intimate connection; in many 



