HO THE ORIGIN OF LIFE 



of chemical reactions can be kept up, and the 

 continual flow of matter which is a characteristic 

 property of the cell can be maintained, unless the cell 

 has a definite structure which controls the direction 

 of the flow. For Verworn and many other physio- 

 logists believe that the structure is the result of 

 the directive flow of the molecules of the substance 

 constituting the cell ; so that their entrance and 

 exit always take place in the same direction. It 

 is not easy to see how the flux could be kept up 

 in this way in bodies so large as a cell, relatively 

 to the size of the constituent molecules, the smallest 

 cell visible being about 1,000 times the diameter 

 of a molecule. With membranes, however, which 

 serve as semi-permeable walls, it is easy to see 

 how it might be directed, even if there is no actual 

 clue as to the manner in which the circulation or 

 flux is maintained. 



It is supposed that the fact that a cell, from which 

 a portion has been cut off, if the nucleus has not been 

 also removed, can again acquire its original form, 

 necessitates the structure should depend upon the 

 flux and not the flux upon the structure. It is 

 no doubt true that the flux does depend upon the 

 nucleus, but that the structure of the cell should 

 also depend upon the flux, even if it also depended 

 on the nucleus, is that which it is so difficult to see 

 the need of. 



The enormous potentiality of the cell involves a 

 highly complicated structure, and no doubt something 

 more ; and it is upon this something more that 



