98 HISTORY OF THE OCEAN'S 



what I have called subvital areas, which I belie\e to be a form of 

 adsorption on clay particles in estuaries. The third stage is that of 

 polymerization and the formation of independent, purely organic, 

 coacervates without mineral support. These are what Pirie has 

 called the "eobionts." In the fourth stage we have the appearance 

 of what are called organelles, composed of nucleoprotein. After 

 that follow the fifth, sixth, and seventh stages, of more advanced 

 organelles with membranes leading to the nucleated cellular 

 organisms of the type of present day life; I shall not discuss these 

 in any detail. 



There are quite sufficient problems to be dealt with in the early 

 stages to occupy scientists of a large number of disciplines for a 

 long time. The general principles I have tried to use in working 

 out the origin of life are those which have been used with success 

 in all the previous attempts at establishing origins at different 

 levels of organization from galaxies to human societies. The first 

 of these is essentially the same as the uniformitarian principle used 

 in the first place by Lyell in his analysis of geological phenomena, 

 namely, as far as possible, by treating the past as if it were a 

 backwards extension of the present. It means that, except when 

 we have positive reasons not to believe it, we must imagine that 

 the same kind of phenomena that occurred in the past occurs now, 

 and then trace their possible consequences. 



The second principle which I feel should be used is that intro- 

 duced by Henderson (1913) in his Fitness of the Environment. This 

 is that the subsequent stages of complicated systems make use of 

 the inherent properties of those simpler stages already present. 

 Life, which is built out of the substance of the classical elements of 

 water and air, consequently makes use of the particular forms and 

 properties of those substances. This, for instance, limits life for 

 practical purposes to the region between 0°C and, say, 80°C, with 

 a maximum somewhere in the region of 30° to 40°C. The special 

 functions which are played in life by some ions and atoms, espe- 

 cially those of potassium, phosphorus, sulfur, and iron, depend not 

 only on their being quantum mechanically adapted to these 

 functions but also on the actual abundance of these atoms in the 

 primitive ocean. 



