IN LIVING MATTER 11 



such substances, the variations in rate of action, and the regulation 

 of the manifold intercurrent reactions running simultaneously 

 within the minute compass of a single cell, even more powerfully 

 than the mere synthesis of the substances point to a controlling 

 and regulating type of energy different to anything outside living 

 matter. The reversal of chemical action from period to period, 

 and the sudden change in chemical activities produced by the 

 activity of the nervous system, have no parallel outside the realm 

 of living cells. 



Much has been made of the fact that intracellular enzymes 

 have been isolated from living cells which are capable of pro- 

 ducing actions hitherto only observed in the presence of the 

 cell, and it has been surmised that all or nearly all the chemical 

 activity of the cell may be due to the action of a large number 

 of such intracellular enzymes. It has, in fact, been supposed 

 that if a solution could be prepared containing the proper 

 number of enzymes, each in appropriate concentration, that the 

 solution would act much like a cell. 



Without disparaging the importance and value of such work 

 of separation of intracellular enzymes, it may, however, be urged 

 that there is in such a view no explanation of the phasic activity 

 of the cell, no taking into account of the action of the living 

 cell in co-ordinating, so to speak, the myriad activities going, on 

 within it whereby the whole process is regulated. Such a solution 

 of enzymes compared with a living cell would be like a horde of 

 savage warriors compared to a civilised and disciplined army of 

 soldiers, or a mass of unicellular organisms compared to a highly 

 differentiated mammal. 



There must obviously in the cell be some type of energy con- 

 trolling all this metabolic activity, and this is the role played by 

 the biotic energy of the cell. 



VI. The osmotic phenomena of the cell demand for their ex- 

 planation the presence of a type of energy not found elsewhere 

 than in living structures. 



Even in the case of those cells of the body which in form 

 look most like membraneous structures, viz. the air-cells of the lung 

 and the thin endothelial cells of the wall of lymphatic and blood 

 capillaries, it has been clearly shown that the laws of diffusion 

 and osmosis as observed in the case of inert, non-living mem- 

 branes are not obeyed. These structures are not inert membranes, 



