ON THE STRUCTURE OF CELLS 135 



amceba, can we attempt to construct anything 

 that will even approximate to it. But the vital 

 process in that which we can and that which we 

 cannot bring about is found to be ultimately the 

 same. 



In both cases the organism is, whether natural or 

 artificial, " a nucleated mass of protoplasm," as Max 

 Schultze defined a cell ; and in both cases this 

 nucleated mass of protoplasm can go through the 

 various processes which are associated with vitality 

 in the organised mass. Thus it is not so much upon 

 the process of vitality itself, as upon the minutest 

 and ultra-microscopic structure of the cell in which 

 vitality occurs, that the actual differences in the 

 subsequent development of the cell depend. The 

 morphology of the artificial cell is simple enough ; 

 that of the natural cell may be, and in most cases 

 certainly is, vastly more complicated. But in out- 

 line it is the same ; and the actual process by 

 which the vital actions are maintained, it would 

 appear, are in the outline, too, pretty much the same. 



It is generally supposed that chlorophyll is the 

 substance in the nucleus by which the process of 

 vitality is performed. But in the artificial cell there 

 is no chlorophyll. This, however, is merely one of 

 the many points in which, as we say, they differ. 

 The points in which they do agree seem to be those 

 which constitute some type of vitality, even if the 

 method by which these are actually accomplished 

 may be different. It is, however, a question of a 

 somewhat debatable nature as to whether chlorophyll 



